Introduction of Glass Cockpit Avionics 

into Light Aircraft

Safety Study

NTSB/SS-01/10

PB2010-917001 National 

Transportation 

Safety Board

NTSB/SS-10/01

PB2010-917001

Notation 7954A

Adopted March 9, 2010

Safety Study

Introduction of Glass Cockpit Avionics into Light Aircraft

National 

Transportation 

Safety Board

490 L’Enfant Plaza, S.W.

Washington, D.C. 20594
National Transportation Safety Board. 2010. Introduction of Glass Cockpit Avionics into Light 

Aircraft. Safety Study NTSB/SS-10/01. Washington, DC.

Abstract: This study used manufacturer records, aircraft investigation information, and a tailored subset 

of general aviation activity survey data to assess how the transition to electronic primary flight display 

(PFD) avionics has affected the safety of light aircraft. The study also evaluated the resources and 

requirements supporting the transition to this new technology. The results of this study suggest that, for 

the aircraft and time period studied, the introduction of glass cockpit PFDs has not yet resulted in the 

anticipated improvement in safety when compared to similar aircraft with conventional instruments. 

Advanced avionics and electronic displays can increase the safety potential of general aviation aircraft 

operations by providing pilots with more operational and safety-related information and functionality, but 

more effort is needed to ensure that pilots are prepared to realize that potential. The Federal Aviation 

Administration (FAA), manufacturers, aviation industry groups, and academia have an established history 

of collaboration through the FAA Industry Training Standards (FITS) program initiative for supporting 

aircraft model-specific and scenario-based training techniques that would teach pilots “higher-order 

thinking skills.” However, the FAA has changed the focus of the FITS initiative and has to date relied on 

manufacturers and commercial vendors to deliver the equipment-specific training originally envisioned 

for FITS. Adoption of uniform equipment-specific training elements by the FAA to ensure pilots have 

adequate knowledge of aircraft equipment operation and malfunctions, as well as improved reporting of 

equipment malfunctions and service difficulties, is likely to improve the safety of general aviation 

operations beyond those involving aircraft with glass cockpit displays. However, such actions are 

particularly important in order to achieve the potential safety benefits associated with advanced cockpit 

technologies in light aircraft.

The National Transportation Safety Board (NTSB) is an independent federal agency dedicated to promoting 

aviation, railroad, highway, marine, pipeline, and hazardous materials safety. Established in 1967, the agency is 

mandated by Congress through the Independent Safety Board Act of 1974 to investigate transportation accidents, 

determine the probable causes of the accidents, issue safety recommendations, study transportation safety issues, and 

evaluate the safety effectiveness of government agencies involved in transportation. The NTSB makes public its 

actions and decisions through accident reports, safety studies, special investigation reports, safety recommendations, 

and statistical reviews.

Recent publications are available in their entirety on the Internet at <http://www.ntsb.gov>. Other information about 

available publications also may be obtained from the website or by contacting:

National Transportation Safety Board

Records Management Division, CIO-40

490 L’Enfant Plaza, SW

Washington, DC 20594

(800) 877-6799 or (202) 314-6551

NTSB publications may be purchased, by individual copy or by subscription, from the National Technical 

Information Service. To purchase this publication, order report number PB2010-917001 from:

National Technical Information Service

5285 Port Royal Road

Springfield, Virginia 22161

(800) 553-6847 or (703) 605-6000

The Independent Safety Board Act, as codified at 49 U.S.C. Section 1154(b), precludes the admission into evidence 

or use of NTSB reports related to an incident or accident in a civil action for damages resulting from a matter 

mentioned in the report.
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Contents

Figures........................................................................................................................................... iii

Abbreviated Terms........................................................................................................................v

Executive Summary.................................................................................................................... vii

Chapter 1: Background.................................................................................................................1

Introduction of Glass Cockpit Displays into Light Aircraft ............................................................1

History of Advanced Cockpit Avionics...........................................................................................4

Advanced Avionics in General Aviation...................................................................................4

Previous Lessons Learned ........................................................................................................5

General Aviation Research to Date..................................................................................................7

General Aviation Safety Record ......................................................................................................8

Chapter 2: Study Design and Methodology...............................................................................11

Study Design Issues.......................................................................................................................11

Methodology..................................................................................................................................12

Study Aircraft Fleet.................................................................................................................13

Activity Survey.......................................................................................................................14

Accident Data .........................................................................................................................15

Analyses.........................................................................................................................................15

Statistical Comparisons ..........................................................................................................16

Chapter 3: Quantitative Analysis Results..................................................................................18

Description of Study Fleet .............................................................................................................18

Description of Study Accidents.....................................................................................................19

Accident Information.....................................................................................................................19

Accident Involvement.............................................................................................................20

Accident Severity....................................................................................................................21

Activity, Exposure Data, and Accident Rates................................................................................22

Flight Conditions ...........................................................................................................................25

Time of Day............................................................................................................................25

Weather Conditions.................................................................................................................27

Flight Plan Filed .....................................................................................................................28

Purpose of Flight............................................................................................................................29

Planned Length of Flight ........................................................................................................31

Phase of Flight ........................................................................................................................32

Accident Event Type...............................................................................................................33

Accident Pilot Information ............................................................................................................34

Number of Pilots.....................................................................................................................34

Pilot Age .................................................................................................................................34

Pilot Certificate Level.............................................................................................................35

Pilot Instrument Rating...........................................................................................................35

Pilot Flight Hours ...................................................................................................................36
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Summary of Quantitative Analysis Results...................................................................................37

Chapter 4: Qualitative Assessment ............................................................................................40

FAA Requirements and Guidance Materials.................................................................................40

Equipment-Specific Training.........................................................................................................41

Manufacturer Training Programs and Materials............................................................................43

Aircraft Manufacturers ...........................................................................................................43

Avionics Manufacturers..........................................................................................................44

Insurance Requirements.................................................................................................................44

Chapter 5: Case Study Review ...................................................................................................46

Pilot Expectations Regarding Glass Cockpit Displays..................................................................46

Equipment Design and Reliability.................................................................................................48

Standardization of Instrument Design and Operation....................................................................51

Interpretation of Equipment Malfunctions.....................................................................................54

Equipment-Specific Training.........................................................................................................56

Tracking Equipment Function and Reliability...............................................................................58

Chapter 6: Data Recording in Glass Cockpit Avionics............................................................61

Chapter 7: Discussion..................................................................................................................64

Accident Involvement and Accident Rates....................................................................................64

Safety Issues...................................................................................................................................65

Training Resources and Requirements...................................................................................65

Providing Pilots with Information about Display Operation and Limitations........................66

Equipment-Specific Training Requirements...........................................................................67

Equipment Malfunction Training ...........................................................................................68

Tracking Service Difficulties and Equipment Malfunctions..................................................69

Summary.......................................................................................................................................70

Conclusions...................................................................................................................................71

Findings..........................................................................................................................................71

Recommendations........................................................................................................................72

Appendix: Study Accidents.........................................................................................................74
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Figures

Figure 1. Example of a light aircraft conventional cockpit............................................................ 3

Figure 2. Example of a light aircraft glass cockpit. ....................................................................... 3

Figure 3. Annual general aviation accident and fatal accident totals, 1999–2008......................... 9

Figure 4. Annual general aviation accident and fatal accident rates, 1999–2008........................ 10

Figure 5. General aviation and on-demand Part 135 average annual flight hours by age of 

aircraft, 2006................................................................................................................................. 12

Figure 6. New registrations of aircraft study fleet by cockpit display configuration and year.... 18

Figure 7. Accumulated study aircraft fleet size by cockpit configuration and year..................... 19

Figure 8. Distribution of glass cockpit cohort aircraft and accidents per year............................. 21

Figure 9. Comparison of study accidents by severity of outcome. .............................................. 22

Figure 10. Comparison of study accidents by time of day........................................................... 26

Figure 11. Combined 2006 and 2007 flight hour distribution by time of day and cockpit 

configuration................................................................................................................................. 26

Figure 12. Comparison of study accidents by weather. ............................................................... 27

Figure 13. Combined 2006 and 2007 flight hour distribution by weather and cockpit 

configuration................................................................................................................................. 28

Figure 14. Comparison of study accidents by flight plan filed.................................................... 29

Figure 15. Comparison of study accidents by purpose of flight. ................................................. 30

Figure 16. Combined 2006 and 2007 flight hour distribution by purpose of flight and cockpit 

configuration................................................................................................................................. 31

Figure 17. Comparison of study accidents by phase of flight...................................................... 32

Figure 18. Comparison of study accidents by event type and aircraft configuration. ................. 33

Figure 19. Comparison of number of pilots aboard study accident aircraft................................. 34

Figure 20. Comparison of study accident pilots by certificate level............................................ 35

Figure 21. Comparison of study accident pilots by instrument rating. ........................................ 36

Figure 22. Illustration of a conventional airspeed indicator mechanism, copied from the FAA 

Instrument Flying Handbook. ....................................................................................................... 52

Figure 23. Illustrations of the internal mechanisms that drive analog attitude and heading 

indicator instruments, copied from the FAA Pilot’s Handbook of Aeronautical Knowledge. ...... 53
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Figure 24. Illustration of an AHRS, copied from the FAA Pilot’s Handbook of Aeronautical 

Knowledge..................................................................................................................................... 54

Figure 25. FAA instrument rating knowledge test sample: instrument malfunction interpretation 

(pitot tube intake and drain blockage). ......................................................................................... 55
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Abbreviated Terms

AC advisory circular

ADAHRS Air Data Attitude Heading Reference System

AERI Airmanship Education Research Initiative

AFM aircraft flight manual

AGATE Advanced General Aviation Transport Experiments

AHRS attitude and heading reference system

AOPA Aircraft Owners and Pilots Association

ATP airline transport pilot

CAB Civil Aeronautics Board

CB circuit breaker

CFR Code of Federal Regulations

CPS certification process study

CRT cathode ray tube

FAA Federal Aviation Administration

FITS FAA Industry Training Standards

GA general aviation

GAATAA General Aviation and Air Taxi Activity and Avionics Survey

GAMA General Aviation Manufacturers Association

GIFD Garmin Integrated Flight Display

G-LOC G-induced loss of consciousness

GPS global positioning system

IFR instrument flight rules

IMC instrument meteorological conditions

MFD multifunction flight display

NASA National Aeronautics and Space Administration

nm nautical miles

NTSB National Transportation Safety Board 
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PFD primary flight display

PTS Practical Test Standards

SDR service difficulty report

SFAR special federal aviation regulation

TAA technically (also, technologically) advanced aircraft

TSO technical standard order

TSRV Transport Systems Research Vehicle

VFR visual flight rules

VMC visual meteorological conditions
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Executive Summary

In a span of only a few years, the cockpits of new light aircraft have undergone a 

transition from conventional analog flight instruments to digital-based electronic displays 

commonly referred to as “glass cockpits.” These new displays integrate aircraft control, 

autopilot, communication, navigation, and aircraft system monitoring functions, applying 

technology previously available only in transport-category aircraft. The enhanced function and 

information capabilities of glass cockpits represent a significant change and potential 

improvement in the way general aviation pilots monitor information needed to control their 

aircraft. The National Transportation Safety Board (NTSB) initiated this study to determine if the 

transition to glass cockpits in light aircraft has improved the safety record of those aircraft.

Three different approaches were used in this study. First, a retrospective statistical 

analysis of manufacturer records, aircraft investigation information, and activity survey data was 

conducted to compare the accident experience of recently manufactured light single-engine 

airplanes equipped and not equipped with glass cockpit displays. Second, an evaluation of glass 

cockpit training requirements and resources was conducted to characterize the training and to 

identify areas for potential safety improvement. Finally, accident cases were reviewed to identify 

emerging safety issues associated with the introduction of glass cockpit displays into this class of 

aircraft. 

The statistical analysis found that for 2002–2008, light single-engine aircraft equipped 

with glass cockpit displays experienced lower total accident rates—but higher fatal accident 

rates—than the same type of aircraft equipped with conventional analog instrumentation. 

Accidents involving glass cockpit aircraft were more likely to be associated with 

personal/business flights, longer flights, instrument flight plans, and single-pilot operations, 

while accidents involving conventional analog cockpit aircraft were more likely to be associated 

with instructional flights, shorter flights, and two-pilot operations. Accident pilots flying glass

cockpit equipped aircraft were found to have higher levels of pilot certification and more total 

flight experience than those flying conventional aircraft.

The evaluation of light aircraft glass cockpit training requirements found that the Federal 

Aviation Administration (FAA) has been updating training handbooks and test standards to 

incorporate generic information about electronic flight instrument displays. However, current 

airman knowledge written tests (such as private pilot, instrument rating, commercial pilot, and 

flight instructor certificates) do not assess pilots’ knowledge of the functionality of glass cockpit 

displays. In addition, the FAA has no specific training requirements for pilots operating glass 

cockpit-equipped light aircraft. The lack of equipment-specific training requirements from the 

FAA results in a wide range of initial and recurrent training experiences among pilots of glass 

cockpit aircraft. With the exception of training provided by airframe manufacturers with the 

purchase of a new aircraft, pilots must currently seek out and obtain equipment-specific glass 

cockpit training on their own. 
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The review of accidents involving light aircraft equipped with glass cockpits found that 

pilots’ experiences and training in conventional cockpits do not prepare them to safely operate 

the complex and varied glass cockpit systems being installed in light aircraft today. Further, the 

lack of information provided to pilots about glass cockpit systems may lead them to 

misunderstand or misinterpret system failures. As a result, there is a need for new training 

procedures and tools to ensure that pilots are adequately prepared to safely operate aircraft 

equipped with glass cockpit avionics.

The results of this study suggest that the introduction of glass cockpits has not resulted in 

a measurable improvement in safety when compared to similar aircraft with conventional 

instruments. The analyses conducted during the study identified safety issues in two areas: 

• The need for pilots to have sufficient equipment-specific knowledge and 

proficiency to safely operate aircraft equipped with glass cockpit avionics.

• The need to capture maintenance and operational information in order to assess 

the reliability of glass cockpit avionics in light aircraft.

As a result of this safety study, the NTSB made six recommendations to the FAA: five 

address training requirements and one addresses reporting requirements.
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Chapter 1: Background

Introduction of Glass Cockpit Displays into Light Aircraft

In a span of only a few years, the cockpits of light aircraft1 have undergone a transition 

from conventional flight instruments to integrated, computerized displays commonly referred to 

as glass cockpits.2 This change has occurred rapidly. Glass cockpit avionics first started to appear 

in light aircraft as noncertified systems installed in experimental and amateur-built aircraft.

Cirrus Design Corporation began the transition to glass cockpits in Federal Aviation 

Administration (FAA)-certified light aircraft in 2003 when it started delivering single-engine 

piston airplanes with electronic primary flight displays (PFD). The new displays quickly became 

standard equipment in the company’s SR20 and SR22 models. Cessna Aircraft Company, Piper 

Aircraft Incorporated, Mooney, and Hawker Beechcraft soon followed, and data from the 

General Aviation Manufacturers Association (GAMA) indicate that by 2006, more than 90 

percent of new piston-powered, light airplanes were equipped with full glass cockpit displays.3

In addition to flight instruments, the previously separate components for autopilot, 

communication, navigation, and aircraft systems have been integrated into glass cockpit displays 

to provide flight management, terrain and traffic avoidance, enhanced/synthetic vision displays, 

and upset recovery functions. Autopilots and global positioning systems (GPS) in particular have 

become standard components in the avionics systems of light aircraft. Several manufacturers of 

glass cockpit displays now produce displays with supplemental type certification for retrofit 

installation in existing aircraft, suggesting that the number of aircraft equipped with full glass 

cockpits will continue to grow.

4

This study was designed to test the hypothesis that the transition to glass cockpit avionics 

in light aircraft will improve the safety of their operation. The study also sought to evaluate the 

resources and requirements supporting the transition to this new technology. To accomplish these 

goals, this study included three separate analyses, as described in this study report: 

The introduction of this advanced technology into light aircraft 

has brought with it a new set of potential safety concerns to the National Transportation Safety 

Board (NTSB), such as equipment design and operation; pilot performance and training; and new 

accident investigation techniques.

 1 The term “light aircraft” is used throughout this report in reference to aircraft with a maximum gross weight 

less than 12,500 pounds and certified under 14 Code of Federal Regulations Part 23. The statistical comparisons 

included in this study were limited to a specific group of light aircraft: the single-engine piston aircraft typically 

used in general aviation operations. 2 The term “glass cockpit” refers to the use of computer screens rather than analog gauges.

3 General Aviation Airplane Shipment Report, End-of-Year 2006 (Washington, DC: General Aviation 

Manufacturers Association, 2007) indicates that 92 percent of the 2,540 piston airplanes delivered during 2006 were 

equipped with glass cockpit electronic flight displays. 4 This study was limited to factory-installed cockpit displays and did not include any analyses of retrofit 

installations of glass cockpit equipment. 
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• A retrospective statistical analysis of accidents and activity data from two cohorts5

• A qualitative review of FAA and industry training resources and requirements related to 

glass cockpit displays conducted to characterize the training and identify areas for 

potential safety improvement.

of 

recently manufactured airplanes produced with and without electronic PFDs, conducted 

to identify any differences in activity, accident rates, or accident circumstances associated 

with glass cockpit displays.

• A review of accident case studies conducted to identify emerging safety issues associated 

with the introduction of glass cockpit displays into this class of aircraft. 

Changing from conventional instruments to glass cockpit displays has created new 

challenges for interface and display design with implications for the way pilots monitor 

information in the cockpit. However, the differences between conventional and glass cockpit 

displays extend beyond appearance (figures 1 and 2). Each of the conventional round-dial 

instruments relies on electromechanical, pneumatic, or pressure-sensitive components to 

generate and display specific aircraft performance and control parameters, such as airspeed, 

altitude, heading, pitch and bank attitude, rate of climb, and rate of turn. In contrast, glass cockpit 

displays rely on computerized systems that integrate multiple data inputs and controls. Glass 

cockpit displays can present more information in the space required for conventional instrument 

panels, but the increase in information places greater demands on pilot attention and creates a 

risk of overloading pilots with more information than they can effectively monitor and process. 

The complexity of the integrated computerized systems that drive glass cockpit displays may 

also limit pilots’ understanding of the functionality of the underlying systems.

The typical light aircraft glass cockpit consists of at least two displays: a primary flight 

display, or PFD, and a multifunction flight display (MFD). A PFD replaces individual flight 

instruments to display the airspeed, altitude, attitude, and rate information that pilots use for 

aircraft control.6 As the name “multifunction” suggests, a wide range of supplementary and 

status information can be selected for display on an MFD. Typical MFDs supplement or replace 

discrete navigation, communication, weather displays, and system status information, such as

engine and fuel gauges. They can also display navigational charts, airport diagrams, and 

electronic checklists. For this study, a glass cockpit aircraft is defined as having at least a PFD.

7

 5 The term “cohort” is used in statistics to refer to a group of subjects, in this case aircraft, that share similar 

characteristics. The aircraft cohorts in this study were all single-engine, piston-powered airplanes manufactured during 

the same 5-year period, with either glass or conventional cockpit instruments. 6 Electronic PFDs replace pressure-sensitive mechanical instruments with an air data computer to process static 

and dynamic pressure values for airspeed, altitude, and associated rate information. Computerized PFDs also replace 

conventional mechanical gyroscopic flight instruments with an attitude and heading reference system (AHRS) that uses 

sensors in three axes to calculate heading, attitude, and yaw information. Integrated PFD processing subsystems are 

usually further integrated with aircraft autopilot and navigation systems. 7 Some light aircraft with conventional flight instruments have been manufactured or retrofitted with MFDs and/or 

GPS equipment with moving map displays. In this study, the classification of a glass cockpit is based on the primary 

flight instrument display, consistent with the industry consensus definition of an integrated cockpit/flightdeck provided 

in GAMA Publication 12 - Recommended Practices and Guidelines for an Integrated Cockpit/Flightdeck in a 14 CFR 

Part 23 Airplane: “...at a minimum, an integrated cockpit/flightdeck must include electronic display and control of all 

primary airplane airspeed, altitude and attitude instruments, and all essential navigation and communication functions.” 

See <http://www.gama.aero/files/gama_publication_12_p23cockpit_april_2005_pdf_498cadb978.pdf>. 
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Figure 1. Example of a light aircraft conventional cockpit.

Figure 2. Example of a light aircraft glass cockpit.

NTSB accident investigators now encounter glass cockpit-equipped aircraft more 

frequently than in the past, and the onboard data recording capabilities in many of these displays 

have enabled investigators to obtain detailed recordings that document specific actions, events, 
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or equipment operations that would not be available with conventional instruments. However, 

not all manufacturers include recording capabilities in their equipment, so these records are not 

always available. Further, conventional analog instruments can be physically examined8 for 

indications of preaccident operation, but the software-based systems that drive electronic 

displays leave no evidence to indicate how they were functioning before or during an accident 

unless data are intentionally recorded.9

History of Advanced Cockpit Avionics

Electronic flight displays were first developed for military applications in the 1960s, and 

by the 1970s, computer-driven cathode ray tube (CRT) displays began replacing 

electromechanical instruments in commercial transport-category airplanes. The use of CRTs led 

to the moniker “glass cockpit,” which is still commonly applied to aircraft that incorporate 

digital flight displays, even though lighter weight, liquid-crystal-display or light-emitting diode 

technologies have replaced CRTs. 

In 1974, the National Aeronautics and Space Administration (NASA) started testing a full 

glass cockpit in a specially equipped Boeing 737 as part of the Transport Systems Research 

Vehicle (TSRV) project. The typical transport-category airplane cockpit at that time was crowded 

with more than 100 instruments and gauges. Integrated displays were developed in conjunction 

with increased automation as a means of reducing some crew tasks and combining aircraft 

control, position, and status information into a few space-saving displays.10

Although the airframe and engine systems in light aircraft are not nearly as complex, the 

glass cockpit displays now being used in these aircraft share similarities with their transportcategory predecessors, such as integrated flight management and autopilot functions, 

communications, and detailed navigation displays. The range of features offered in the cockpit 

displays that are now being introduced into light aircraft has moved ahead of many of their 

transport-category counterparts to include infrared imaging systems, synthetic vision, highwayin-the-sky navigation, and upset recovery capabilities. 

Much of NASA’s 

TSRV work made its way into the design of cockpits of civilian transport-category aircraft with 

the introduction of the Boeing 757/767. 

Advanced Avionics in General Aviation

Much of the research leading to the recent introduction of glass cockpit displays into light 

aircraft developed from the NASA-sponsored Advanced General Aviation Transport Experiments 

(AGATE) consortium. In response to decreasing general aviation activity and aircraft sales 

during the 1980s and 1990s, NASA, the FAA, the general aviation industry, and academia joined 

 8 Such evidence includes rotational scoring on gyros or witness marks from needles hitting the face of instrument 

displays during impact. 9 Chapter 6 of this report contains more discussion of data recording functions in electronic flight displays. 10 L. E. Wallace, Airborne Trailblazer: Two Decades with NASA Langley Boeing 737 Flying Laboratory, NASA 

SP-4216 (Washington, DC: National Aeronautics and Space Administration, 1994).
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to form AGATE as the first step in pursuit of a new transportation system based on light aircraft. 

The goal of AGATE was to develop new and affordable airframe and avionics technology, 

certification methods, and flight training systems for the next generation of light aircraft used in 

general aviation by adapting technology previously available only in transport-category aircraft 

operated by commercial airlines.11 At the core of the initiative was the vision of replacing shorthaul, intercity air carrier flights with personal flights in small aircraft that would be so easy to fly 

that almost anyone “could get in, select a destination, and go” with minimal training and 

expense.

12 AGATE-sponsored research resulted in new certification and design guidelines for 

affordable composite materials, cockpit displays, and avionics that are now used in such 

airplanes as the Cirrus Design Corporation SR20/22 series, the Diamond Aircraft DA40 series, 

and new models of very light jets.13

With the introduction of this new technology, the FAA and aircraft manufacturers 

anticipated a need to provide specific training for general aviation pilots transitioning from 

conventionally equipped aircraft to those with digital flight displays. To that end, the FAA 

worked with academic and industry partners like the Embry-Riddle Aeronautical University, the 

University of North Dakota, and participating manufacturers to develop the FAA Industry 

Training Standards (FITS) program. The original FITS program plan advocated aircraft typespecific training and the use of scenario-based techniques to teach pilots the “higher-order 

thinking skills” required to safely operate high performance aircraft with advanced automation 

capabilities. To date, several manufacturers and national training providers have developed FITSaccepted training courses. In addition, the FAA is incorporating FITS principles, such as 

scenario-based training, decision-making techniques, and learner-centered grading, into its 

training materials. Using a similar collaborative approach, the FAA has also worked closely with 

manufacturers and industry groups to produce new and/or updated manuals that discuss 

electronic flight displays. Such manuals include the Advanced Avionics Handbook,

The AGATE program ended in 2001 before the real-world 

effects of many of these changes could be assessed.

14 Instrument 

Flying Handbook,15 and Pilot’s Handbook of Aeronautical Knowledge.

16

Previous Lessons Learned

The applicability of air carrier experience may be limited due to the diversity in general 

aviation equipment, operations, and pilot population. Nevertheless, the large body of research 

into human-machine interaction and aircraft control issues stemming from the increase in flight 

 11 E. M. Bolen, president of the General Aviation Manufacturers Association, statement before the 

Subcommittee on Science, Technology, and Space, U.S. Senate Commerce Committee (April 24, 2001). 12 “Affordable Alternative Transportation: AGATE – Revitalizing General Aviation,” NASA Facts, July 2, 

1996, FS-1996-07-02-LaRC (Hampton, Virginia: National Aeronautics and Space Administration, 1996), available

at <http://www.nasa.gov/centers/langley/news/factsheets/AGATE.html> (accessed September 1, 2009). 13 K. Gale, The Advanced General Aviation Transport Experiments (AGATE) Alliance, AGATE Alliance 

Commercialization Impact Report, 1995-2000, NASA AGATE-WP 12.0-120011-114 (San Francisco, California:

STARnet, 2002). 14 Advanced Avionics Handbook, FAA-H-8083-6 (Washington, DC: Federal Aviation Administration, 2009). 15 Instrument Flying Handbook, FAA-H-8083-15A (Oklahoma City, Oklahoma: Federal Aviation 

Administration, AFS-600: 2008). 16 Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25A (Oklahoma City, Oklahoma: Federal 

Aviation Administration, AFS-600: 2008).
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deck automation in transport-category aircraft during the 1980s and 1990s holds lessons for what 

can be expected in light aircraft. In general, advances in automated control systems have led to 

substantial improvements in equipment reliability and have increased the precision of complex 

aircraft control functions. Airlines quickly realized that glass cockpit avionics, and the automated 

control and flight management functions that accompanied them, would increase efficiency and 

decrease operating costs. New displays also provided crews with far more status and planning 

information. Further, glass cockpit displays are generally lighter and cheaper to maintain than the 

multiple systems they replaced, and the integration of automation with aircraft systems allowed 

aircraft to be certified for operation with a two-person crew.17

Flight crew response to the new technology was also for the most part positive. However, 

the overall effect of increased automation and system integration was to shift workload from task 

performance to the higher level cognitive tasks of planning and systems monitoring. The new 

technology generally reduced workload demands on the crew, but in some cases, the greatest 

reductions occurred during times when workload was already low. In addition, crews began 

reporting that glass cockpit equipment could actually increase workload during emergencies and 

times of high demand because they were often forced to reconfigure the navigation and flight 

management systems in flight to modify routing or approach information.18 Pilot reports and 

observational research also identified crew difficulties when transitioning to glass cockpit 

aircraft19 and occasional confusion with the operation of integrated systems, even among pilots 

who reported feeling as though they understood their systems well.20

Even before electronic displays became common, anecdotal reports from flight crews, as 

well as findings from accidents and research, revealed potential problems if pilots relied too 

heavily on automated systems or if they misunderstood automated system behavior.21 In its 

findings of probable cause on the 1984 Scandinavian Airlines accident at John F. Kennedy 

Airport,22

Apply the findings of behavioral research programs and accident/incident investigations 

regarding degradation of pilot performance as a result of automation to modify pilot 

the NTSB identified the crew’s over-reliance on the aircraft auto throttle system and 

issued the following recommendation to the FAA: 

 17 A presidential task force determined in 1981 that transport-category aircraft such as the MD80 and Boeing 

757/767 could be safely flown with only a two-person crew because automation could be used to replace flight 

engineer duties. See J. L. McLucas, F. J. Drinkwater, and H. W. Leaf, Report of the President’s Task Force on 

Aircraft Crew Complement (Washington, DC: 1981). 18 E. L. Wiener, Human Factors and Advanced Technology (Glass Cockpit) Transport Aircraft, NASA-TR 

177528 (NASA Ames Research Center: National Aeronautics and Space Administration, 1989).

19 N. B. Sarter, D. D. Woods, and C. E. Billings, “Automation Surprises,” G. Salvendy, ed., Handbook of 

Human Factors and Ergonomics, 2nd ed. (New York: Wiley, 1997). 20 N. B. Sarter and D. D. Woods, “How in the World Did We Get Into That Mode? Mode Error and Awareness 

in Supervisory Control,” Human Factors, vol. 37 (1995), pp. 5-19. 21 For example, see E. L. Wiener and R. E. Curry, Flight-Deck Automation Promises and Problems, 

NASA-TM-81206 (NASA Ames Research Center: National Aeronautics and Space Administration, 1980). 22 Scandinavian Airlines System, Flight 90, McDonnell Douglas DC-10-30, John F. Kennedy International 

Airport, Jamaica, New York, February 28, 1984, Aircraft Accident Report NTSB/AAR-84/15 (Washington, DC: 

National Transportation Safety Board, 1984).
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training programs and flight procedures so as to take full advantage of the safety benefits 

of automation technology. (A-84-123)23

Subsequent fatal air carrier accidents, like the April 26, 1994, crash of a China Airlines 

Airbus 300-600 in Nagoya, Japan, and the December 20, 1995, American Airlines Boeing 757 

crash near Cali, Colombia, drew further attention to the issues of human interaction with 

computerized aircraft systems, cockpit displays, and associated data input and communication 

functions. In response to these issues, the FAA commissioned a comprehensive review of crew 

interfaces with advanced flight deck systems. Among the findings were such vulnerabilities as 

the flight crews’ inadequate understanding of complex flight deck systems and their occasionally 

inappropriate decisions about how and when to use automation.24

A 2001 study conducted by the U.S. Army Aeromedical Research Laboratory25 examined 

how the Army’s move to glass cockpits had affected safety in real-world flight operations. The 

study analyzed accident rates of four models of helicopters with conventional and glass cockpit 

configurations. Study results indicated a significantly higher accident rate for the glass cockpit 

configuration group than for the conventional cockpit group. The authors suggested that the 

findings provided reason for concern and discussed several possible reasons for the difference, 

including the possibility that concurrent mission and equipment changes rather than cockpit design 

alone contributed to higher accident rates. Subsequent survey research suggested that even though 

pilots preferred the glass cockpit design and believed it improved safety, they found learning to use 

the displays and maintaining their proficiency to be more difficult and reported issues of higher 

cognitive workload in glass cockpit aircraft than in those with a conventional design.26

General Aviation Research to Date

Less research is available specific to the safety consequences of glass cockpit avionics in 

light aircraft, mostly due to their recent introduction and a general lack of available data. In 

2003, a joint FAA and industry group published a study of technically advanced aircraft (TAA) 

issues27

 23 Closed in 1991, “Acceptable Alternate Action,” based on several actions by the FAA that included 

(1) collaborating with NASA and aviation industry representatives in the development of a comprehensive National Plan 

for Aviation Human Factors; (2) issuing Advisory Circular (AC) 120-35B, Line Operational Simulations: Line-Oriented 

Flight Training, Special Purpose Operational Training, Line Operational Evaluation; and (3) issuing an advanced 

qualification program special federal aviation regulation (SFAR) establishing alternative methods of complying with 

training requirements of 14 CFR Parts 121 and 135 to incorporate advanced training methods and techniques.

based on subject matter expert evaluations and reviews of case studies using the Human 

24 K. Abbott and others, The Interface Between Flightcrews and Modern Flight Deck Systems, Federal Aviation 

Administration Human Factors Team Report (Washington, DC: Federal Aviation Administration, 1996). 25 C. Rash and others, Accident Rates in Glass Cockpit Model U.S. Army Rotary-Wing Aircraft, Army 

Aeromedical Research Laboratory Final Report (Fort Rucker, Alabama: U.S. Army Aeromedical Research 

Laboratory, 2001). 26 C. Rash and others, A Comparison of AH-64 Pilot Attitudes Toward Traditional and Glass Cockpit 

Crewstation Designs, Army Aeromedical Research Laboratory Final Report (Fort Rucker, Alabama: U.S. Army 

Aeromedical Research Laboratory, 2002). 27 General Aviation Technically Advanced Aircraft, FAA-Industry Safety Study: Final Report of TAA Safety Study Team,

<http://www.faa.gov/training_testing/training/fits/research/media/TAA Final Report.pdf> (Washington, DC: Federal 

Aviation Administration, 2003). This report defines a TAA as follows: “A General Aviation aircraft that contains the 

following design features: Advanced automated cockpit such as MFD or PFD or other variations of a Glass Cockpit, or a 

traditional cockpit with GPS navigation capability, moving map display and autopilot.”
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Factors Analysis and Classification System (HFACS).

28

A 2005 analysis by the Aircraft Owners and Pilots Association (AOPA) Air Safety 

Foundation

The study was prompted by an industry 

observation that accident numbers for TAAs were no better than for conventionally equipped 

aircraft—contrary to expectation. Most safety problems identified in the study were attributed to 

pilot judgment errors rather than issues associated with pilot-equipment interaction. 

Unfortunately, findings from the study are of limited applicability to the current generation of 

aircraft because none of the accident aircraft included in the study was equipped with a PFD.

29 came to conclusions similar to those in the 2003 FAA report and concluded that the 

TAA accident record at the time was generally similar to that of legacy aircraft. Like the FAA’s 

TAA study, the report attributed most accidents to faulty pilot judgment rather than problems 

with the avionics or the pilot-aircraft interface. In a 2007 followup study,30 the AOPA Air Safety 

Foundation compared accidents involving TAAs to general aviation accidents from 2003 through 

2006. This study suggested that the number of TAAs involved in accidents was smaller than 

would be expected, given the percentage of these aircraft in the overall population: while TAAs 

made up 2.8 percent of the aircraft fleet, they were involved in 1.5 percent of total accidents and 

2.4 percent of fatal accidents. Additional results suggested that differences in aircraft usage might 

have contributed to the distribution of accidents. For example, the percentage of accidents 

involving weather was higher for TAAs, and the percentage of accidents during takeoff and 

climb was lower.31

General Aviation Safety Record

These findings would be expected if the TAAs were used for long distance, 

point-to-point flying rather than primary flight training. The AOPA studies were limited because 

comparisons were made to the diverse group of aircraft used in general aviation operations, and 

the flight-hour or usage data needed to determine differences in exposure or to verify the 

resulting conclusions were not available.

The annual number of general aviation accidents, fatal accidents, and fatalities occurring 

in the United States has been decreasing for many years. In 2008, U.S. general aviation 

experienced the lowest number of fatal accidents and its second-lowest number of total accidents 

since 1944.32

 28 For an explanation of the HFACS classification, see S. A. Shappell and D. A. Wiegmann, The Human 

Factors Analysis and Classification System—HFACS, DOT/FAA/AM-00/7 (Washington, DC: Federal Aviation 

Administration, 2000).

As shown in figure 3, annual general aviation accident and fatal accident totals 

29 Technically Advanced Aircraft: Safety and Training (Frederick, Maryland: Aircraft Owners and Pilots 

Association, Air Safety Foundation, 2005). 30 Technically Advanced Aircraft: Safety and Training (Frederick, Maryland: Aircraft Owners and Pilots 

Association, Air Safety Foundation, 2007). 31 The AOPA Air Safety Foundation report was based on data extracted from the NTSB’s aviation accident 

database; however, the reported accident categories are assigned by Air Safety Foundation analysts and may differ 

from the NTSB findings of probable cause. 32 Based on data compiled from Annual Review of U.S. General Aviation Accidents Occurring in Calendar Year 

1968 (Washington, DC: National Transportation Safety Board, 1969); Annual Review of Aircraft Accident Data, U.S. 

General Aviation Accidents Calendar Year 1979, NTSB/ARG-81-1 (Washington, DC: National Transportation Safety 

Board, 1981); Annual Review of Aircraft Accident Data, U.S. General Aviation Accidents Calendar Year 1989, 

NTSB/ARG-93/01 (Washington, DC: National Transportation Safety Board, 1993); and National Transportation Safety 

Board, Aviation Accident Statistics: Accidents, Fatalities, and Rates, 1989–2008, U.S. General Aviation (available at 

<http://www.ntsb.gov/aviation/Table10.htm>).
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declined from 1999 through 2008. Without any additional information, such as activity data, this 

trend might be interpreted as being due in part to the introduction of new, advanced aircraft 

technologies. 

Figure 3. Annual general aviation accident and fatal accident totals, 1999–2008.

However, general aviation activity has also been decreasing. Normalizing the number of 

accidents by annual exposure data—in this case, the FAA’s annual general aviation flight hour 

estimates—results in a rate that more accurately represents safety risk.33

 33 See chapter 2, Study Design and Methodology, for a detailed discussion of the FAA’s General Aviation and 

Air Taxi Activity and Avionics (GAATAA) Survey.

In contrast to annual 

accident totals, general aviation accident rates and fatal accident rates per 100,000 flight hours 

have remained relatively steady over the last decade. Annual accident rates and trends from 1999 

through 2008 are presented in figure 4.
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Figure 4. Annual general aviation accident and fatal accident rates, 1999–2008.

It should be noted that the diversity of aircraft, operations, and pilots comprising U.S. 

general aviation can easily mask localized safety issues and trends. Further, most analyses of 

aggregate activity and accident data lack the specificity and detail necessary to assess the effect 

of glass cockpits. Therefore, this study compared cohorts comprising conventional and glass 

cockpit aircraft of similar age and type, and a corresponding subset of activity data for both 

cohorts, to better assess how the introduction of glass cockpit display technology into light 

aircraft has affected the safe operation of those aircraft. 
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Chapter 2: Study Design and Methodology

To determine how the introduction of glass cockpit avionics has affected the safe 

operation of light aircraft, the NTSB conducted both quantitative and qualitative assessments, as 

well as a case study review. The goals for the quantitative portion of this study were to identify 

any differences in the operational characteristics of conventional and glass cockpit aircraft and to 

determine how the introduction of glass cockpit avionics into light aircraft has affected safety. 

These goals were accomplished by comparing the accident records of two cohorts of airplanes 

produced during the 5 years from 2002 to 2006, as well as aircraft activity and usage data 

collected from 2 years of owner surveys. The cohorts selected had similar airframes, numbers of 

engines, and engine types but differed principally in their type of primary flight instrumentation: 

that is, one cohort comprised glass cockpit aircraft and the other included aircraft equipped with 

conventional displays.

For the qualitative assessment, which is discussed in chapter 4, the NTSB reviewed 

changes in training, resources, and requirements associated with the transition to glass cockpits. 

To that end, the NTSB reviewed FAA and manufacturer-provided training materials, visited 

aircraft manufacturers to observe factory transition training, and spoke with representatives of 

the aviation insurance industry about their requirements for owners and operators of glass 

cockpit aircraft. For the case study review, described in chapter 5, the NTSB reviewed the 

circumstances of accidents involving the glass cockpit cohort to identify safety issues unique to 

glass cockpit displays. 

Study Design Issues

An assessment of the safety consequences of a specific aircraft equipment change is 

easily confounded34 if that change is associated with differences in aircraft use, pilot 

demographics, or additional equipment changes. For example, the average number of annual 

flight hours is known to decrease with aircraft age (see figure 5).35

 34 A statistical confound is a variable not accounted for in statistical comparisons but correlated to study 

variables in such a way that may result in misleading study findings. For example, a study may find that drownings 

increase when ice cream sales increase. Without additional study controls, one might erroneously conclude that there 

is a causal relationship between these variables. However, the confounding variable in this case is likely the time of 

year because ice cream sales and swimming activity both increase during the summer months.

Comparisons of newly built 

aircraft with all aircraft or with older aircraft of similar type are therefore likely to 

mischaracterize risk exposure. New aircraft with new equipment capabilities may also attract a 

new demographic of pilots to general aviation who may use their aircraft differently than pilots 

flying older models. 

35 General Aviation and Air Taxi Activity and Avionics Survey, 2006 (Washington, DC: Federal Aviation 

Administration, 2007), <http://www.faa.gov/data_research/aviation_data_statistics/general_aviation/CY2006/>. 
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Figure 5. General aviation and on-demand Part 135 average annual 

flight hours by age of aircraft, 2006.

Potential confounds related to aircraft age, equipment, and usage were controlled for to 

the extent possible36

Methodology

in the present study by identifying groups of similar aircraft of similar age, 

with and without glass cockpits, and then gathering the information necessary to further identify 

any differences in use or user population. 

Quantitative data analyses in the current study included (1) a comparison of specified 

aircraft models manufactured during the 5 years from 2002 through 2006, the years that spanned 

the transition of the fleet from conventional to glass cockpit displays, (2) statistical comparisons 

of retrospective accident data for the years 2002 through 2008 by display type, and (3) a 

comparison of aircraft and flight activity data obtained from the FAA aircraft registry and an

analysis of GAATAA Survey data for the years 2006 and 2007.

37

 36 The models of aircraft included in the study vary to some degree with regard to performance, range, and 

capability, but the study fleet represents a more homogenous group of aircraft than is typical of general aviation 

operations as a whole. 

Aircraft cockpit display 

configuration was determined using aircraft manufacturer records. All accident data were 

extracted from the NTSB Aviation Accident Database. Study analyses were limited to accidents 

involving U.S.-registered aircraft. 

37 The FAA conducts an annual survey of aircraft owners to generate information on general aviation and 

on-demand Part 135 aircraft use and activity. The stated purposes of the survey are to (1) anticipate and meet 

demand for National Airspace System facilities and services, (2) evaluate the impact of safety initiatives and 

regulatory changes, and (3) build more accurate measures of the safety of the general aviation community.
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The NTSB worked with GAMA and individual manufacturers to identify the airplanes of 

interest manufactured from 2002 through 2006 and to classify the instrumentation of each 

airframe by serial number. Once this study fleet was identified, the NTSB worked with the FAA 

and its survey contractor to generate activity estimates from the survey responses collected from 

owners of those aircraft, grouped by type of cockpit display. The resulting activity estimates 

derived from the subset of GAATAA Survey data from 2006 and 2007 were used along with 

NTSB Aviation Accident Database records to develop accident rate measures by cockpit display 

type for those years.

The period of study represented a unique window of opportunity during which both the 

aircraft equipment information and activity records necessary to compare similar aircraft, both

with and without glass cockpits, were available. Before the FAA changed its GAATAA Survey 

methodology in 2006, the activity data needed to compare newly manufactured aircraft were 

insufficient.

38

Study Aircraft Fleet

Similarly, such comparisons will become increasingly challenging in the future 

due to the growing number of glass cockpit retrofit options, which will make it difficult to 

readily identify aircraft equipped with this technology.

The NTSB Aviation Accident Database does not contain sufficient detail to identify 

accident aircraft by both year of manufacture and cockpit equipment. The NTSB therefore used 

supplemental data available in the FAA aircraft registry, which includes build date information. 

Because some of these data are missing, the NTSB worked with GAMA and aircraft 

manufacturers to identify—by serial number—single-engine piston airplanes manufactured in 

the 5 years from 2002 through 2006 and the cockpit display configuration of each aircraft. In 

addition to being selected because they bridged the introduction of PFDs into this group of 

aircraft, the years 2002−2006 were selected because they were covered by an expanded sampling

methodology introduced in the 2006 GAATAA Survey, which included contacting the owners of 

all aircraft manufactured during the preceding 5 years for participation in the survey.

Once the list of aircraft was compiled, that information was used to summarize the data 

and compare accident involvement by cockpit display type. Aircraft selected for the study 

included the following makes and models of airplanes manufactured between 2002 and 2006.

• Cessna Aircraft Corporation

• 172

• 182 series

• 206 series

 38 Starting with the 2006 survey, the FAA modified its GAATAA Survey methodology to include a 100-percent 

sample of aircraft manufactured during the preceding 5 years. In comparison, the 2005 survey sampled only about 

16 percent of single-engine piston airplanes. The final number of valid survey responses was still limited, however, by 

aircraft owners who declined to participate and aircraft that were subsequently exported, destroyed, or otherwise inactive. 

For specific details associated with the sampling methodology used in previous surveys, see the 2005 GAATAA Survey, 

appendix A, <http://www.faa.gov/data_research/aviation_data_statistics/general_aviation/CY2005/>. Washington, DC: 

Federal Aviation Administration, 2006.
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• Cirrus Design Corporation

• SR20

• SR22

• Diamond Aircraft

• DA40

• Lancair/Columbia Aircraft/Cessna Aircraft Company

• 300/35039

• Mooney

and 400

• M20 series

• Piper Aircraft Inc.

• PA-28-161

• PA-28-181

• PA-28-201

• PA-32-301 series

• PA-46-350P

• Hawker Beechcraft Corporation

• 36 series

A total of 8,364 airplanes were identified from FAA registry records for inclusion in the 

study. Of those, 2,848 were identified for inclusion in the conventional cockpit display cohort, 

and 5,516 were included in the glass cockpit cohort.

Activity Survey

As stated above, the FAA modified its GAATAA Survey methodology in 2006 by 

increasing its survey sample to include all aircraft manufactured during the preceding 5 years. 

The NTSB took advantage of this change to obtain the activity and usage data necessary to make 

statistical comparisons based on cockpit display type. Working with the FAA and the contractor 

responsible for conducting the survey,40

 39 The Lancair 300 was only produced with conventional cockpit displays, but it is similar to the 

Columbia/Cessna 350 produced with glass cockpit displays.

the NTSB was able to obtain analyses of survey 

responses from the selected aircraft models manufactured from 2002 to 2006 that had undergone 

a change in standard equipment from conventional to glass PFD cockpit displays. Limiting the 

sample to a group of aircraft manufactured within a 5-year period also reduced the likelihood of 

confounding effects from changes known to occur as aircraft age, such as declining levels of 

flight hours. The study sample was further defined to include single-engine, piston-powered 

airplanes to allow direct comparisons between aircraft of relatively similar operational and 

performance capability. 

40 The FAA conducts the GAATAA Survey under a contract with PA Consulting Group, Madison, Wisconsin.
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Because the 2006 survey included aircraft that were manufactured during 2006—and 

therefore had not experienced a full year of operation—activity estimates for those aircraft were 

also calculated from the 2007 GAATAA Survey responses. Due to the new survey sampling 

methodology, a total of 2,738 responses from the 2006 survey and 2,357 total responses from the 

2007 survey were identified for inclusion in this study. The targeted aircraft activity and usage 

data obtained for the study were similar in format and content to the published GAATAA Survey 

results, with separate datasets for conventional aircraft and glass cockpit-equipped aircraft. The 

NTSB conducted several summary analyses of active aircraft, flight activity, and usage data from 

GAATAA Survey responses to identify any differences associated with the type of cockpit 

display.

Accident Data 

Data from the NTSB Aviation Accident Database were used, along with the registration 

and serial number information provided by manufacturers, to identify aircraft in each cohort that 

were involved in accidents between 2002 and 2008 and to capture the details of those accidents. 

NTSB accident data include details of the accident event, such as type of occurrence, phase of 

flight, and environmental conditions; pilot demographics and experience; and accident 

investigation findings.41

Analyses

These data were used to compare the accident experience of the two 

cohorts and to make statistical comparisons of the accidents each cohort experienced.

Summary statistics were calculated to compare the aircraft cohorts on variables such as 

the number of aircraft, hours flown, usage details, and accidents. For those aircraft in the study 

sample that had been involved in accidents,42 univariate comparisons were made between the 

conventional and glass cockpit groups on the basis of data collected during the accident 

investigation, including accident occurrences and findings, weather and operational details, and 

accident pilot demographics and experience.43

Statistical tests appropriate to the various accident-related variables were used to 

determine the extent to which the conventional and glass cockpit cohorts differed. 

Because the study was targeted at a relatively 

small set of aircraft, the number of comparisons that could be made between glass cockpit and 

conventional aircraft as a function of operational and pilot characteristics was limited by the 

sample sizes (number of accident cases) for each comparison. 

 41 See appendix for the list of accidents included in the study. 42 Study accident analyses were limited to U.S.-registered aircraft. 43 Univariate comparisons are those that compare differences between two groups based on one variable in 

isolation—for example, percentage of accidents resulting in fatality by cockpit type. 
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Statistical Comparisons

Chi-square statistics44were used to compare the cohorts on categorical accident variables 

such as weather, time of day, and purpose of flight. Mann-Whitney U tests45

Accident flight information

were used to 

compare differences in continuous variables, including planned flight distance, pilot age, and 

flight experience. The following variables were selected for analysis: 

• Accident severity

• Planned length of flight

• Purpose of flight

• Day/night and visual meteorological conditions 

• Visual/instrument meteorological conditions 

• Instrument/visual flight rules flight plan 

• Accident phase of flight and event details

Pilot information

• Number of pilots aboard accident aircraft

• Age at the time of the accident 

• Highest certificate level

• Instrument rating

• Flight hours

 44 Chi-square is a statistical test that can be used to determine whether two or more groups differ significantly 

with respect to the proportional distribution of a given characteristic or quality. The chi-square statistic compares the 

observed counts of a categorical variable for one or more groups to those expected by the relative distribution of the 

groups. The chi-square test results in a measure of significance or probability that the observed distributions of a 

variable were similar for the study groups. A very low probability, such as 5 percent or less, indicates that the groups 

likely differed with regard to the variable of interest. 45 Mann-Whitney U is a statistical test for assessing differences between two groups with regard to the 

distribution of a continuous variable. The test results in a measure of the probability that observations of a variable 

from both groups are similar, which is also an indication of whether observations of that variable are greater for one 

group than the other. 
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Accident rates were calculated for comparison with the applicable exposure data, such as 

number of aircraft or flight hours. Standard error values were included with GAATAA Survey 

results and calculated rate comparisons when appropriate.46

The following rate comparisons were calculated:

• Accidents and fatal accidents per active aircraft

• Accidents and fatal accidents per flight hour

• Accidents and fatal accidents by time of day

• Accidents and fatal accidents by weather condition

• Accidents and fatal accidents by purpose of flight

Accident records for the 2002–2008 period covered by this study provided enough data to 

make statistically reliable comparisons between the two study groups. While the activity data 

were limited to 2 years of FAA surveys, the similarities between the patterns of aircraft usage 

reported by survey respondents and the patterns in the accident data for the 7-year study period 

indicate that the accident rates derived from the activity data provide valid comparisons between 

the conventional and glass cockpit groups. 

 46 Rate calculations, such as the number of accidents occurring annually per flight hour, are estimates of the 

“true” rate of an event based on historical occurrences of that event. Accident rates are subject to variability due to 

chance, particularly when the number of events and/or the size of the population of interest is small. The larger the 

population and/or number of events being studied, the more likely it is that the computed rate will be close to the 

true rate. The variability of a rate can be evaluated by computing a standard error that includes both the number of 

events and the size of the denominator (for example, registered aircraft, active aircraft, or flight hours) measured. In

this report, standard error values are presented as a percentage of the associated value or rate. Rates based on small 

numbers are particularly unstable, which is reflected in a high percent of standard errors. Standard error values were 

either excluded for rates based on fewer than 10 events or noted as such. Note that most of the accident rates 

calculated from the 2006 and 2007 GAATAA Survey data are based on small numbers and that the resulting 

differences are therefore not statistically significant but are provided as possible further explanation of the 

differences in the 2002–2008 accident record for these aircraft.
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Chapter 3: Quantitative Analysis Results

Description of Study Fleet

By comparing manufacturer aircraft serial number data with FAA aircraft registration 

records, the NTSB identified 2,848 single-engine piston airplanes for the conventional cockpit 

display cohort and 5,516 for the glass cockpit cohort, all manufactured between 2002 and 

2006.47 Figure 6 illustrates the rapidly changing distribution of the aircraft included in the study. 

Most aircraft in the conventional display cohort were manufactured between 2002 and 2004, 

while aircraft in the glass cockpit cohort first appeared on the FAA registry in 2003. 

Figure 6. New registrations of aircraft study fleet by cockpit display configuration 

and year.

After 2004, the size of the conventional cohort remained relatively constant, while the 

size of the glass cockpit cohort increased rapidly, surpassing the conventional cohort in 2005 and 

nearly doubling it in 2006. Figure 7 shows the accumulated size of the study fleet for each year 

from 2002 through 2006 and the accumulated number of aircraft in the conventional and glass 

cockpit cohorts each year.

 47 The study aircraft fleet was identified by comparing the aircraft serial number and cockpit display data 

provided by manufacturers with FAA aircraft registry data. An aircraft was included in the study fleet if it ever 

appeared on the registry, regardless of whether it was subsequently deregistered or exported, or the registration later 

became inactive.
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Figure 7. Accumulated study aircraft fleet size by cockpit configuration and year.

Description of Study Accidents

Study analyses of accidents included the years from 2002 through 2008. The years of 

aircraft manufacture from 2002–2006 were selected to correspond with the 2006 GAATAA 

100-percent sampling methodology for newly built aircraft. However, although the activity and 

accident data included aircraft manufactured throughout 2006, the number of study aircraft did 

not stabilize until the end of that year. Accident records for 2007 and 2008 were therefore 

included to represent 2 full years of accidents associated with the study aircraft, unaffected by 

the addition of newly manufactured aircraft.

Accident Information

This section contains summary analyses of the relative accident occurrences and rates 

associated with the conventional and glass cockpit cohorts defined in this study. Comparisons of 

accident numbers are limited because aircraft can be used differently and in ways that expose one 

group of aircraft to more or less risk for severe accident outcomes than another. The validity of

comparisons of accidents with aircraft manufacturing and registration records is likewise limited 
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by the possibility that aircraft may be sold, exported, deregistered, or placed in storage.

48

Accident Involvement 

Therefore, the accident data provided in this section should be considered within the context of 

corresponding activity data. Active aircraft information, flight activity, and aircraft usage data 

from the 2006 and 2007 GAATAA Surveys are presented throughout this section for comparison 

with FAA aircraft registry information and NTSB accident records from 2002 through 2008. Due 

to the unequal cohort sizes, the aircraft and accident data are presented as percentages of the 

respective cohort totals to facilitate interpretation. The complete list of study accidents is 

included in the appendix. 

A comparison of the list of study aircraft with NTSB records identified 266 total 

accidents involving study aircraft between 2002 and 2008, 62 of which resulted in one or more 

fatal injuries.49

Comparisons of accident involvement from 2002 through 2006 must account for changes 

in the size of the study fleet due to the newly manufactured aircraft added to the fleet each year. 

The distribution of study aircraft and accidents associated with the glass cockpit cohort (as 

shown in figure 8) shows that the percentage of accidents involving glass cockpit aircraft was 

smaller than would be expected based on the percentage of the study fleet that those aircraft 

represented. During 2004 and 2005, fatal accidents for conventional and glass cockpit aircraft 

were proportional to the percentage of the study fleet they represented, but starting in 2006, the 

glass cockpit group began to experience proportionately more fatal accidents. Over the entire 

period from 2002 through 2008, aircraft in the glass cockpit cohort showed a disproportionately 

lower rate of total accidents per registered aircraft but a disproportionately higher rate of fatal 

accidents per registered aircraft than those in the conventional cohort. 

Of the 266 study accidents, 141 accidents—23 of them fatal—involved 

conventionally equipped aircraft. The remaining 125 total accidents and 39 fatal accidents 

involved glass cockpit aircraft. It is important to note that direct comparisons of the overall 

accident totals would be misleading in this case because of the changes in the sizes of the cohorts 

during the time period analyzed. 

 48 For example, data provided by GAMA indicate that approximately 30 percent of aircraft produced in 2007 

and 2008 were exported. Similar data do not exist for 2002–2006, but the number of aircraft that remained active in 

U.S. civil aviation is likely well below the 8,354 total aircraft that had appeared on the FAA aircraft registry. Further 

support for this suggestion comes from the active aircraft estimate results of the 2006 and 2007 FAA GAATAA 

Survey cited in table 2 of the Activity, Exposure Data, and Accident Rates section later in this chapter. 

49 One accident (SEA03LA180) was excluded from study analyses because it occurred during the factory flight 

test. 
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a The study aircraft fleet included aircraft manufactured between 2002 and 2006; therefore, the distribution of glass 

cockpit aircraft in the study aircraft fleet remained constant from 2006 through 2008.

Figure 8. Distribution of glass cockpit cohort aircraft and accidents per year.

Accident Severity

Statistical comparisons of the 2002 through 2008 accident data, independent of the 

registry or survey information, show similar differences in accident severity by cockpit display 

type. As shown in figure 9, the percentage of accidents resulting in fatality was about twice as 

high for the glass cockpit cohort as for the conventional cohort. Of the 266 accidents involving 

study aircraft between 2002 and 2008, accidents involving aircraft in the glass cockpit cohort 

were significantly more likely to be fatal: χ2 (1, N = 266) = 8.216, p = 0.004.50

 50 Throughout this report, the results of chi-square (χ2

) statistical tests are included in the text using the 

following notation (degrees of freedom, N = number of cases compared) = resulting chi-square value, p = 

probability (that is, significance) of the result. The p value can be interpreted as the percent likelihood that the 

observed value occurred by chance. Therefore, a difference that results in a small p value is unlikely to have resulted 

from chance and is more likely the result of differences between the two groups. For the purposes of this study, p 

values of 0.05 (5 percent) and less are considered statistically significant. Refer to table 7 at the end of this chapter 

for a summary of all study chi-square statistical test results.

 
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Figure 9. Comparison of study accidents by severity of outcome.

In addition to the statistical comparisons of accident data from 2002 through 2008, 

GAATAA Survey data were used to develop rates for the years 2006 and 2007 that represent 

accident risk by providing estimates of the number of aircraft actively operated, the number of 

hours flown, and specific characteristics of how those aircraft were operated. Rates based on 

flight activity provide a clearer indication of the relative safety of the conventional and glass 

cockpit configurations by identifying differences in the number of aircraft that were actively 

flying versus those that may have been sold or placed into storage, or that may have become 

inactive for other reasons. Differences between aircraft buyers who opted for a glass cockpit 

airplane can contribute to differences in accident risk, and pilots may use aircraft differently 

based on their avionics capabilities. The 2 years of available GAATAA Survey data were used to 

further explore these possibilities and provide evidence of activity and usage differences to aid 

interpretation of the aircraft’s accident record to date.

51

Activity, Exposure Data, and Accident Rates

Of the 2,848 airplanes included in the conventional display cohort, 935 of the owners 

responded to the 2006 GAATAA Survey, and 472 responded to the 2007 survey. Of the 5,516 

aircraft in the glass cockpit cohort, 1,803 owners responded to the 2006 GAATAA Survey, and 

1,885 responded to the 2007 survey. These responses were used to calculate estimates of the 

number of active aircraft and total hours flown, as well as the number of hours flown by purpose 

of flight, day/night operations, and visual/instrument flight activity in accordance with the 

 51 Note that the study includes statistical comparisons of all accidents involving the study aircraft fleet from 

2002 and 2008. However, GAATAA Survey data were only available for the years 2006 and 2007. No attempt was 

made to apply the 2006 and 2007 survey results to the prior years 2002 through 2005.
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normal GAATAA Survey methodology.

52

Table 1. GAATAA Survey analysis results.

Results of the active aircraft and flight hour analyses 

are presented in table 1 below. 

Year Active Aircraft Flight Hours

Conventional Glass Cockpit Conventional Glass Cockpit

2006 2,412 4,203 593,853 805,152

(0.2% Std. Error) (0.2% Std. Error) (2.6% Std. Error) (1.6% Std. Error)

2007 1,738a 4,205 565,370 838,573

(0.2% Std. Error) (0.2% Std. Error) (4.0% Std. Error) (1.6% Std. Error)

a

The large drop in the estimated number of active conventional aircraft in 2007 was likely due in part to 

increased variability in survey estimates for this group because aircraft manufactured during 2002 were not 

included in the 100-percent 2007 survey sample. This subsequently resulted in fewer total responses for aircraft 

built during 2002, which were exclusively of the conventional cockpit design. The effect of this change is that the 

number of conventionally equipped aircraft and their associated activity were likely higher than the survey 

results indicate for 2007. The effect of this change is also evident in the higher standard error value associated 

with the flight hours for the conventional cohort in 2007.

Dividing the flight hours from the GAATAA Survey by the number of active aircraft 

provides an estimate of the average number of hours flown per aircraft. For the years 2006 and 

2007, the average estimated hours flown per aircraft was 286 for the conventional cohort (246 

hours/aircraft in 2006 and 325 hours/aircraft in 2007) and 195 for the glass cockpit cohort (192 

hours/aircraft in 2006 and 199 hours/aircraft in 2007).

As illustrated in table 2, accident rates calculated from NTSB accident records and 

GAATAA Survey data indicate that the 2006 and 2007 accident rates per 1,000 active aircraft 

were higher for the conventional display cohort, but the fatal rates were higher for the glass 

cockpit cohort for both years. 

Because the study cohorts included only a few thousand aircraft, and the numbers of total 

and fatal accidents within the cohorts were relatively small each year, the 2006 and 2007 activity 

and accident data were summed for comparisons of accident rates and specific accident details to 

provide more stable rate estimates and to reduce the potentially distorting effect of small 

numbers of events on rate calculations. Even when using this approach, the standard errors 

associated with the fatal rates are high due to the relatively small number of total events.

 52 Analyses of the subset of GAATAA Survey data were done by the contractor responsible for conducting the 

survey in accordance with the established survey methodology; however, this is the first published use of a subset of 

GAATAA Survey data for targeted analyses like those included in this report.
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Table 2. Accident rates for 2006 and 2007 per 1,000 active aircraft, by aircraft cockpit 

configuration.

Year Accident Rate Per 1,000 Active Aircraft

Total Fatal

Conventional Glass Cockpit Conventional Glass Cockpit

2006 9.12 7.85 1.24* 2.62

2007 12.08 6.9 1.15* 1.43*

Combined 

2006-2007

10.36 7.37 1.20* 2.02

(15.3% Std. Error) (12.7% Std. Error) (44.9% Std. Error) (24.3% Std. Error)

*Rate based on fewer than 10 events.

As previously stated, comparisons of accident rates based on active aircraft provide a 

better indication of risk than those based on numbers of aircraft manufactured because they do 

not include aircraft that were subsequently exported, placed in storage, or not flown. However, 

accident rates based on owner-reported flight activity provide the best indication of risk because 

they include both the extent of operation and the way the aircraft was operated. Accident rates 

calculated from the survey responses regarding the number of hours flown annually are shown in 

table 3, along with comparison accident rates for all general aviation operations.53

Those results indicate that the total accident rate per 100,000 flight hours was higher for 

the glass cockpit cohort in 2006, but higher for the conventional cohort in 2007. The combined 

2-year accident rates per 100,000 flight hours for 2006 and 2007 were similar for both the glass 

and conventional cohorts (3.77 and 3.71 respectively). The total accident rate for both cohorts 

was less than the 6.63 accidents per 100,000 flight hours for all general aviation operations for 

the same period, reflecting the wide range of aircraft and flight operations included in general 

aviation.

The fatal accident rate for the glass cockpit cohort exceeded the rate of fatal accidents per 

100,000 hours for the conventional cohort for both years, and for all general aviation operations 

in 2006. Like the rates per active aircraft discussed previously, the fatal rates per 100,000 flight 

hours for both cohorts—especially the conventional cohort—have large standard errors due to 

the small number of events. The resulting rates, however, are consistent with the results of other 

study analyses, indicating that accidents involving the glass cockpit cohort were more likely to 

be fatal. The combined fatal accident rate for 2006 and 2007 was higher for the glass cockpit 

cohort (1.03) than for the conventional cohort (0.43). The combined 2006 and 2007 fatal rates for 

both study cohorts were less than the 1.24 fatal accidents per 100,000 hours for all general 

aviation operations for the same period. 

 53 Includes all study accidents.
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Table 3. 2006 and 2007 accident rates per 100,000 flight hours, by cockpit configuration.

Year Accident Rate Per 100,000 Flight Hours

Total Fatal

Conventional Glass Cockpit All General

Aviation†

Conventional Glass Cockpit All General 

Aviation†

2006 3.70 4.10 6.33 0.51* 1.37 1.28

2007 3.71 3.46 6.92 0.35* 0.72* 1.20

Combined 

2006-2007

3.71 3.77 6.63 0.43* 1.03 1.24

(15.3% Std. Error) (12.7% Std. Error) ― (44.2% Std. Error) (19.2% Std. Error) ―

*Rate based on fewer than 10 events. 

†

National Transportation Safety Board, Aviation Accident Statistics: Accidents, Fatalities, and Rates, 1989 - 2008, U.S. General 

Aviation. Available at: http://www.ntsb.gov/aviation/Table10.htm.

At the time of writing, targeted GAATAA Survey flight-hour data were not available to 

calculate 2008 accident rates for the study cohorts. If the hours flown for both cohorts during 

2008 were similar to the averages in 2006 and 2007, the total accident rates for both the 

conventional and glass cockpit cohorts would again be less than the overall general aviation rate. 

However, with 13 fatal accidents during 2008, the fatal rate of aircraft in the glass cockpit cohort 

in this study would well exceed both the conventional cohort and the overall general aviation 

fatal rates for the year.54

Flight Conditions

Accident details and survey responses associated with both cohorts were compared to 

identify any differences in accident circumstances, aircraft use, or pilots that could affect the 

severity of accident outcomes and explain the observed differences between the accident and 

fatal accident rates for the conventional and glass cockpit cohorts. For example, accidents that 

occur at night or in instrument meteorological conditions (IMC) have historically been more 

likely to result in fatality than those that occur during the day in good weather.55

Time of Day

As illustrated in figure 10, the 2002 through 2008 accident data indicate that a higher 

percentage of accidents involving aircraft in the glass cockpit group occurred at night, but the 

difference was not statistically significant: χ2 (1, N = 266) = 3.058, p = 0.080.

 54 For example, if total flight hours were estimated for the study groups by averaging the 2006 and 2007 survey 

results, the 2008 fatal rate for the conventional group would be 0.35 fatal accidents per 100,000 flight hours, and the 

rate for the glass cockpit group would be 1.58, compared to the overall general aviation fatal rate of 1.20 in 2008. 55 Risk Factors Associated with Weather-Related General Aviation Accidents, Safety Study NTSB/SS-05/01

(Washington, DC: National Transportation Safety Board, 2005).
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Figure 10. Comparison of study accidents by time of day.

As figure 11 shows, distribution of GAATAA Survey flight hour estimates by time of day 

for 2006 and 2007 was similar for both cohorts. However, when compared with the accident data 

for those years, the rates of total and fatal accidents per flight hour at night were higher for the 

glass cockpit cohort (see table 4).

Figure 11. Combined 2006 and 2007 flight hour distribution by time of 

day and cockpit configuration.
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Table 4. Combined 2006 and 2007 accident rates per 100,000 flight hours by time of day 

and cockpit configuration.

Total Fatal

2006-2007 Conventional Glass Cockpit Conventional Glass Cockpit

Day 4.01 3.86 0.30 0.87

Night 1.85 3.31 1.23 1.84

Weather Conditions

As shown in figure 12, the 2002 through 2008 accident data indicate that a higher 

percentage of glass cockpit accidents occurred in IMC. The difference in accident weather 

conditions was marginally significant: χ2 (1, N = 264) = 3.639, p = 0.056.

Figure 12. Comparison of study accidents by weather.

GAATAA Survey data regarding flight hours by weather conditions, shown in figure 13, 

indicate that glass cockpit aircraft owners reported a larger percentage of flight time in IMC. A 

comparison of accidents and flight hours during 2006 and 2007 (table 5) shows similar total 

accident rates for both groups in visual meteorological conditions (VMC) but higher total and 

fatal accident rates per flight hour in IMC for the glass cockpit cohort. 
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Figure 13. Combined 2006 and 2007 flight hour distribution by weather 

and cockpit configuration.

Table 5. Combined 2006 and 2007 accident rates per 100,000 flight hours by weather and 

cockpit configuration.

Total Fatal

2006-2007 Conventional Glass Cockpit Conventional Glass Cockpit

IMC 1.63 2.68 1.63 2.34

VMC 3.86 3.94 0.29 0.67

Flight Plan Filed

Consistent with the previous results showing that glass cockpit aircraft spent a higher 

percentage of flight hours in IMC, the aircraft cohorts also differed with regard to flight plan 

filed for the accident flight. Figure 14 shows that among those accidents during 2002 through 

2008 with flight plan information available, pilots in the glass cockpit cohort were significantly 

more likely to have filed an instrument flight rules (IFR) flight plan for the accident flight: 

χ2 (1, N = 250) = 11.718, p = 0.001. GAATAA Survey data do not provide estimates of the 

number of hours flown by type of flight plan.
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Figure 14. Comparison of study accidents by flight plan filed.

Purpose of Flight

The study cohorts differed noticeably with regard to aircraft usage. Figure 15 shows that 

accident flights involving aircraft in the conventional cohort were almost equally split between 

instructional flights and personal/business flights, while glass cockpit accidents were significantly 

more likely to involve personal/business flights: χ2 (1, N = 258) = 31.616, p < 0.001.
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Figure 15. Comparison of study accidents by purpose of flight.

GAATAA Survey results regarding reported aircraft use indicated that a larger percentage 

of the conventional cohort’s activity during 2006 and 2007 involved instructional flights, while 

the glass cockpit aircraft were more often used for personal and business flying (see figure 16). A 

comparison of accidents with reported aircraft use from 2006 through 2007, summarized in 

table 6, indicates that the conventional aircraft experienced higher total accident rates during 

both instructional and personal/business flying. Both cohorts experienced equally low fatal 

accident rates for instructional flights, but the glass cockpit cohort experienced a higher fatal 

accident rate during personal/business flights.
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Figure 16. Combined 2006 and 2007 flight hour distribution by purpose of 

flight and cockpit configuration.

Table 6. Combined 2006 and 2007 accident rates per 100,000 flight hours by purpose of flight 

and cockpit configuration. 

Total Fatal

2006-2007 Conventional Glass Cockpit Conventional Glass Cockpit

Instructional 3.98 2.79 0.20 0.20

Personal/Business 6.62 5.05 1.26 1.65

Planned Length of Flight

Among those accidents for which both point of departure and intended destination were 

known, the median planned length of accident flights associated with the glass cockpit cohort 

was 96 nautical miles (nm), compared to a median of 25 nm for conventional aircraft flights. 

Differences in the planned length of study flights for both cohorts were evaluated using the 

Mann-Whitney U test statistic. Results indicated that accident flights involving the glass cockpit 

cohort were significantly longer than those for aircraft in the conventional cockpit cohort 

(U = 5649.5, N (conventional) = 140, N (glass cockpit) = 122, p < 0.001).

56

 56 Throughout this report, the results of Mann-Whitney U statistical tests are included in the text using the 

following notation (calculated value of the U statistic, n1 and n2 = number of cases in each study cohort, p = 

probability, or significance of the result). Like the results of the chi-square test previously discussed, the p value can 

be interpreted as the percent likelihood that the observed value occurred by chance. The Mann-Whitney test is 

calculated by ranking each of the observed values and summing the rank scores within the groups being compared. 

The sums of ranks are compared for both groups to identify the group with the higher result. In this case the sum of 

ranks for the conventional group is less than the sum of ranks for the glass cockpit group, so the significant U score 

can be attributed to accident flights involving glass cockpit aircraft being longer than those involving aircraft with 

conventional cockpit instruments. Refer to table 8 at the end of this chapter for a summary of all study 

Mann-Whitney U statistical test results.

Much of the 
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difference in planned flight distance between the two cohorts can be attributed to the large 

percentage of conventional aircraft operating on local or very short flights, versus the percentage 

of glass cockpit aircraft, which were more likely to be operating on longer flights. Of the 140 

conventional aircraft accidents with flight length information, 71 (51 percent) were conducting 

local flights that were planned to return to the departure airport or very short flights of less than 

25 nm. Only 26 percent of glass cockpit accident flights were local—or less than 25 nm—but 

42 percent of accident flights involving glass cockpit aircraft were planned for more than 150 nm 

versus only 16 percent of flights associated with conventional aircraft. 

Phase of Flight

In general, aircraft in the glass cockpit cohort were involved in a higher percentage of 

accidents during the in-flight phases from initial climb to approach, while conventional aircraft 

were involved in higher percentages of accidents during takeoff, landing, and “other,” which 

include taxiing and standing (see figure 17).

Figure 17. Comparison of study accidents by phase of flight. 57

 57 Totals do not sum to 100 percent due to rounding.
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Accident Event Type

Glass cockpit aircraft were involved in higher percentages of loss-of-control in flight and 

collision-with-terrain events, and conventional aircraft were involved in more loss-of-control on

ground and hard-landing events. This is consistent with the results of the previous comparison

showing more glass cockpit accidents during in-flight phases and more takeoff and landing 

accidents for the conventional cohort. A summary comparison of accident event types is 

presented in figure 18. 

Figure 18. Comparison of study accidents by event type and aircraft configuration. 58

The higher percentage of collisions with terrain versus all other events for the glass 

cockpit cohort was the only statistically significant difference between the two cohorts in 

accident events: χ2 (1, N = 255) = 3.980, p = 0.046.

 58 Totals do not sum to 100 percent due to rounding.
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Accident Pilot Information

Information regarding accident pilots was compared to identify differences that might 

have affected the safety record of study aircraft. For example, if one cohort was more likely to be 

flown by less experienced pilots, the accident record would likely be worse for those aircraft.

Number of Pilots 

As illustrated in figure 19, aircraft with conventional cockpits were more likely to have 

two flight crewmembers aboard than those with glass cockpits, which were more likely to be 

operated by a single pilot. The difference in the number of flight crew was statistically 

significant: χ2 (1, N = 266) = 7.063, p = 0.008. In approximately half of the conventional aircraft 

cases with two pilots, the second pilot was identified as a flight instructor, which is consistent 

with the previously presented results indicating that conventional aircraft were more likely to be 

used for instructional flights.

Figure 19. Comparison of number of pilots aboard study accident aircraft.

Pilot Age 

Age data were available for 257 of the 266 accident pilots considered in the study. 

Accident pilots in the glass cockpit cohort ranged in age from 18 to 76, with a median age of 47. 

Accident pilots in the conventional cohort ranged in age from 17 to 77, with a median age of 43. 

Accident pilots flying glass cockpit aircraft were significantly older than those flying 

conventional aircraft (U = 6736.5, N (conventional) = 139, N (glass cockpit) = 118, p = 0.014). 

Much of the difference between the conventional and glass cockpit study cohorts with regard to 

age can be attributed to differences in the percentage of young pilots. Of the 139 accident pilots 
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in the conventional aircraft cohort whose age was known, 38 (27 percent) were under 30 years 

old. In contrast, for the glass cockpit cohort, only 14 of the 118 accident pilots (12 percent) for 

whom age information was available were under 30 years old.

Pilot Certificate Level

Of those accident pilots for whom certificate information was available, 26 percent held 

airline transport pilot (ATP) or commercial certificates, 50 percent held private pilot 

certificates, and 24 percent held student pilot certificates. As shown in figure 20, nearly equal 

proportions of the two cohorts held commercial or ATP certificates, but the two cohorts 

differed significantly with regard to student and private pilot certificates: χ2 (2, N = 261) = 

21.931, p < 0.001. In comparison, the data concerning the FAA’s U.S. civil airman certificate 

for 2002 through 200859 indicate that an average of approximately 14 percent of active pilots 

held a student pilot certificate, 38 percent a private pilot certificate, and 43 percent a 

commercial pilot certificate or ATP.

Figure 20. Comparison of study accident pilots by certificate level.

Pilot Instrument Rating

As illustrated in figure 21, approximately 65 percent of accident pilots in the glass 

cockpit cohort were rated for instrument flight, compared to 37 percent of those in the 

 59 See <http://www.faa.gov/data_research/aviation_data_statistics/civil_airmen_statistics/2008/>.
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conventional cohort.60 The difference in instrument rating between the aircraft cohorts was 

statistically significant: χ2 (1, N = 257) = 20.828, p < 0.001. In comparison, the FAA’s U.S. civil 

airman statistics indicate that, on average, 51 percent of the active pilot population from 2002 to 

2008 held an instrument rating. 

Figure 21. Comparison of study accident pilots by instrument rating.

Pilot Flight Hours

The most commonly available measures of accident pilot flight experience were total flight 

hours in all aircraft and total time in the accident aircraft make and model. The total flight time of 

accident pilots in glass cockpit aircraft ranged from 22 to approximately 25,000 hours, while the 

total flight time for accident pilots in conventional aircraft ranged from 1 to 23,000 hours. The 

median number of total flight hours for glass cockpit pilots was higher than the median total flight 

hours for pilots of conventional aircraft (466 hours and 167 hours, respectively), and accident 

pilots in the glass cockpit cohort had significantly more total flight hours than those in the 

conventional cohort: U = 5503.0, N (conventional) = 138, N (glass cockpit) = 118, p <0.001. 

Flight experience in the accident aircraft make and model for pilots in glass cockpit 

aircraft ranged from 11 to approximately 1,430 hours and for accident pilots in conventional 

aircraft, from 1 to approximately 6,200 hours. Median flight experience in make and model for 

glass cockpit pilots was higher than for those flying conventional aircraft (99 hours and 70 hours, 

 60 Insufficient data were available to compare instrument flight experience and currency at the time of the 

accident.
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respectively). However, the overall distributions of flight time in the accident make/model were 

not significantly different: U = 6087.5, N (conventional) = 129, N (glass cockpit) = 106, p= 0.148. 

It is important to note that data concerning flight experience in aircraft make and model made no 

distinction in cockpit design, so some pilots may have been experienced in the aircraft type while 

having little experience with the particular cockpit display in the aircraft.

Summary of Quantitative Analysis Results

Study comparisons of total and active aircraft, flight hours, and accidents showed similar

patterns of accident rates for study aircraft. A comparison of the accidents from 2002 through 

2008 involving the glass cockpit and conventional study cohorts with the number of registered 

aircraft indicates that the glass cockpit aircraft study cohort experienced a lower accident rate but 

a higher fatal accident rate. Analyses of the study-specific estimates obtained from the FAA’s 

2006 and 2007 GAATAA Surveys indicate that the 2-year, 2006 and 2007 accident rate per 

100,000 flight hours was similar for both study groups, but the fatal accident rate per flight hour 

was higher for the glass cockpit cohort.

Statistical comparisons of accident characteristics identified several variables with 

distributions significantly different between the conventional and glass cockpit groups, including 

(1) accident severity, (2) purpose of accident flights, (3) planned length of accident flight, 

(4) number of pilots, (5) pilot age, (6) pilot certification level, (7) pilot total flight experience, 

and (8) pilot instrument rating. Accidents involving glass cockpit aircraft were more likely to be 

associated with personal/business flights, longer flights, and single-pilot operations, while 

conventional aircraft were more likely to be associated with instructional flights, shorter flights, 

and two-pilot operations. Accident pilots of glass cockpit-equipped aircraft were older, held 

higher levels of pilot certification, were more likely to hold an instrument rating, and had more 

flight hours than those flying aircraft with conventional instruments. The glass cockpit cohort 

was involved in more accidents in IMC, but the difference was only marginally significant. 

These results are consistent with GAATAA Survey data indicating that the conventional 

cohort flew more instructional flight hours. A younger pilot group, two-pilot crews, and shorter 

flights are consistent with new pilots learning to fly. Aircraft in the conventional cockpit cohort 

were more likely to be involved in an accident but less likely to be involved in a fatal accident, 

which is also consistent with the conventional aircraft being used to conduct more instructional 

flights, which historically have had lower fatal accident rates than personal flying.61

Differences in accident rates between the study cohorts followed a similar pattern. The 

2-year fatal accident rates for 2006 and 2007 were similarly low for both cohorts during 

instructional flights. The total accident rate was higher for conventional aircraft during both 

instructional and personal/business flying, but the fatal accident rate was highest for glass 

cockpit aircraft during personal/business flights. 

 61 Annual Review of U.S. General Aviation Accident Data, 2005, Annual Review NTSB/ARG-09/01, “Focus on 

General Aviation Safety: Instructional Flight” (Washington, DC: National Transportation Safety Board, 2009).
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Finally, accident and fatal accident rates were higher for the glass cockpit cohort in IMC 

and at night despite the aircraft being flown by pilots with higher levels of certification and more 

flight experience—and the additional capabilities of glass cockpit displays, which were intended 

to improve the safety of those flight operations. The tables that follow summarize the results of 

all statistical tests included in this study. Table 7 summarizes all comparisons of categorical 

accident variables in this chapter, with total numbers of cases included in each comparison, 

relative percentages, chi-square values, and significance. 

Table 7. Summary of chi-square analyses.

Total 

Accidents

Conventional Glass cockpit χ2

 p

N % within cohort N % within cohort

Accident Severity 266 8.216 0.004

Fatal 23 16% 39 31%

NonFatal 118 84% 86 69%

Total 141 125

Light Condition 266 3.058 0.080

Day 122 87% 98 78%

Night 19 13% 27 22%

Total 141 125

Weather 264 3.639 0.056

VMC 129 92% 105 85%

IMC 11 8% 19 15%

Total 140 124

Flight Plan 250 11.718 0.001

VFR/None 110 83% 76 64%

IFR 22 17% 42 36%

Total 132 118

Purpose of Flight 258 31.616 < 0.001

Instructional 66 49% 19 16%

Personal/Business 70 51% 103 84%

Total 136 122

Accident Event Type 255 3.980 0.046

Collision with Terrain 11 8% 19 16%

Other 126 92% 99 84%

Total 137 118

Flight Crew Aboard 266 7.063 0.008

Single Pilot 117 83% 117 94%

Two Pilots 24 17% 8 6%

Total 141 125

Highest Pilot Certificate 261 21.931 < 0.001

Student 49 35% 14 12%

Private 55 40% 76 62%

Commercial or ATP 35 25% 32 26%

Total 139 122

Pilot Instrument Rating 257 20.828 < 0.001

Not Instrument Rated 88 63% 41 35%

Instrument Rated 51 37% 77 65%

Total 139 118
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Table 8 summarizes all comparisons of continuous accident variables in this chapter, with 

total numbers of cases included, median values, sums of ranks, Z-scores and Mann-Whitney U 

values, and significance. 

Table 8. Summary of Mann-Whitney analyses.

N Median Sum of Ranks Z U p

Pilot Age 2.467 6736.5 0.014

Conventional 139 43yrs 16466.5

Glass Cockpit 118 47yrs 16686.5

Total 257

Pilot Total Flight Time 4.469 5503.0 <0.001

Conventional 138 167hrs 15094.0

Glass Cockpit 118 466hrs 17802.0

Total 256

Pilot Flight Time in Make/Model 1.445 6087.5 0.148

Conventional 129 70hrs 14472.5

Glass Cockpit 106 99hrs 13257.5

Total 235

Planned Flight Length 4.807 5649.5 <0.001

Conventional 140 25nm 15519.5

Glass Cockpit 122 96nm 18933.5

Total 262
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Chapter 4: Qualitative Assessment

In addition to conducting the retrospective data analyses included in this study, the NTSB 

reviewed FAA and manufacturer training materials and programs applicable to glass cockpit 

aircraft and visited aircraft manufacturers to observe factory training available to general aviation 

pilots transitioning to glass cockpit avionics. The NTSB also spoke with several representatives of 

the aviation insurance industry regarding experience and training requirements for coverage of 

glass cockpit-equipped light aircraft. This review enabled the NTSB to understand and assess the 

current state of training requirements and glass cockpit training available to general aviation pilots. 

FAA Requirements and Guidance Materials 

The FAA has established minimum requirements for persons wishing to obtain initial or 

additional pilot certification and ratings. Pilot applicants must log a minimum number of flight 

hours, meet specified flight and ground training requirements, and pass a knowledge and/or 

practical test to receive a pilot certificate or additional qualifications, such as an instrument 

rating. Knowledge tests are designed to sample an applicant’s understanding of the information 

necessary to exercise the privileges of a particular certificate or rating. Prospective pilots must 

pass the required knowledge test and obtain an instructor’s endorsement to be eligible to take the 

practical test for a certificate or rating. The current pool of questions for FAA airman knowledge 

tests, such as private pilot, instrument rating, commercial pilot, and flight instructor certificates, 

do not assess pilots’ knowledge of the functionality of glass cockpit displays.62

The FAA currently has no specific initial or recurrent training requirements for pilots of 

Part 23 certified

However, most of 

the FAA’s training handbooks and Practical Test Standards (PTS) have been updated to 

incorporate information about electronic flight instrument displays. 

63 aircraft related to cockpit equipment or avionics. There are general requirements 

for all pilots to be knowledgeable about the operation and limitations of the aircraft they fly—

including all aircraft systems—and to be proficient in the use of those systems. The FAA PTS 

requires that applicants be able to demonstrate proficiency with all equipment installed in their 

airplanes, and the FAA’s most recent Instrument Rating64 and Flight Instructor, Instrument65

 62 Based on the June 26, 2009, revision of FAA airman knowledge test banks, available online: 

<

PTS 

mentions electronic flight displays with regard to knowledge of the operating characteristics of 

installed equipment and operating procedures such as preflight checks. The Aircraft and Equipment 

http://www.faa.gov/training_testing/testing/airmen/test_questions/>. 63 Title 14 CFR Part 23 contains airworthiness standards for airplanes in the normal, utility, acrobatic, and

commuter categories. The maximum takeoff weight of an airplane in the normal, utility, or acrobatic category 

cannot exceed 12,500 pounds, and the maximum takeoff weight of an airplane in the commuter category cannot 

exceed 19,000 pounds. In comparison, 14 CFR Part 25 contains airworthiness standards for airplanes in the transport 

category, which typically have a maximum gross weight of more than 12,500 pounds. 64 FAA-S-8081-9C, available online: 

<http://www.faa.gov/training_testing/testing/airmen/test_standards/media/FAA-S-8081-9C.pdf>. 65FAA-S-8081-4E, available online: 

<http://www.faa.gov/training_testing/testing/airmen/test_standards/media/FAA-S-8081-4E.pdf>.
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Required for the Practical Test section of the PTS also mentions electronic primary flight 

instrument and abnormal or emergency procedures for instrument failures. 

The FAA Instrument Rating PTS specifically addresses electronic flight instruments in its 

guidance to pilot examiners regarding the evaluation of an applicant’s response to instrument 

failures as follows:

The loss of the primary electronic flight instrument display must be tailored to failures 

that would normally be encountered in the aircraft. If the aircraft is capable, total failure 

of the electronic flight instrument display, or a supporting component, with access only to 

the standby flight instruments or backup display shall be evaluated.

Equipment-Specific Training

Even before it began updating its training materials and PTS, the FAA recognized a need 

to improve general aviation pilot training. The FAA developed its FITS initiative in anticipation 

of the increasing demands of managing advanced technology in general aviation cockpits. With a 

focus on scenario-based training techniques, the FITS initiative attempted to make pilot training 

more engaging and more relevant to real-world demands. Another element included in the initial 

FITS initiative was aircraft- and equipment-specific training. 

Findings of the 2003 General Aviation Technically Advanced Aircraft: FAA–Industry 

Safety Study noted a divide between the potential safety benefits of increased use of technology 

and the realization of those benefits, as described below: 

TAAs provide increased “available safety,” i.e., a potential for increased safety. 

However, to actually obtain this available safety, pilots must receive additional training in 

the specific TAA systems in their aircraft that will enable them to exploit the 

opportunities and operate within the limitations inherent in their TAA systems.66

and 

The template for securing this increased safety exists from the experiences with previous 

new technology introductions—the current aircraft model-specific training and insurance 

requirements applicable to high-performance single and multi engine small airplanes. 

However, the existing training infrastructure currently is not able to provide the needed 

training in TAAs.67

The FITS program plan,

68

 66 Finding 4 of the FAA-Industry study. 

published by the FAA in 2003, cited several intended product 

categories. In addition to general FITS training, the program sought to produce a “specific FITS 

67 Finding 5 of the FAA-Industry study. 68 FAA-Industry Training Standards (FITS) Program Plan (Washington, DC: Federal Aviation Administration, 

2003).
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program for a specific aircraft or technology.” The FITS program plan described the intended 

product as follows:

Specific standards will be initially developed in partnership with [manufacturers and 

training centers]. They will prototype and implement initial, transition, recurrent, and 

flight instructor training requirements of their customers and flight operations. Incentive 

mechanisms in these programs will include regulatory incentives within the current 

[Code of Federal Regulations] CFR (i.e. 141.57, Special curricula) as well as industry 

incentives such as insurance. Development will be in conjunction with certification under 

14 CFR Part 142 and Part 141. 

The description went on to suggest that similar specialized training was expected to be 

developed for individual avionics systems and displays and for pilots transitioning to upgraded 

equipment that was being retrofitted into existing aircraft.

The NTSB identified the need for pilots to receive specialized training for advanced 

aircraft equipment in a 1992 special investigation and analysis of several accidents involving the 

Piper Aircraft Corporation model PA-46 airplane.69

Amend 14 CFR 61.31(f) to include integrated flight guidance and control systems as part 

of the ground and flight training requirements specified in subparagraphs (f) (1) (i) and 

(ii). (A-92-88)

The PA-46 included an autopilot and flight 

director system that was an advanced technology for single-engine light aircraft at that time. In 

response to the investigation of several accidents and one incident in which pilots misunderstood 

or misused that system, the NTSB issued the following recommendation to the FAA:

The FAA did not establish the recommended training requirements, but in 1997, it 

enacted 14 CFR 61.31(h) requiring pilots to receive aircraft type-specific training and a logbook 

endorsement for aircraft identified by the Administrator as requiring such training.70

Since publication of the 2003 TAA report and FITS program plan, the FAA has shifted 

the focus of FITS away from equipment-specific training for advanced aircraft systems, as 

mentioned in the original program plan, and has focused instead on updating training manuals 

and promoting instructional techniques, such as scenario-based training and student-led 

performance reviews, for pilots of all aircraft. To date, the FAA has encouraged manufacturers 

On July 30, 

1998, the NTSB noted that the FAA did not plan to make the recommended regulatory changes 

and classified Safety Recommendation A-92-88 “Closed—Unacceptable Action.” One of the 

anticipated actions described in the FITS program plan was development of mandatory pilot 

training and qualification standards in accordance with 14 CFR 61.31(h). This approach would 

have created equipment-specific requirements akin to a type rating for a Part 23 aircraft. The 

program plan suggested that “Promulgation could be through an amendment to the aircraft flight 

manual, which refers to the FITS standard directory.”

 69 Piper Aircraft Corporation PA-46 Malibu/Mirage Accidents/Incident, May 31, 1989, to March 17, 1991, 

Special Investigation Report NTSB/SIR-92/03 (Washington, DC: National Transportation Safety Board, 1992). 70 The type-specific training requirement of 14 CFR 61.31(h) was never applied to the PA-46.
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and training providers to develop specific training but has not incorporated equipment-specific 

elements into its training, testing, or currency requirements. 

Manufacturer Training Programs and Materials

The NTSB observed FITS-accepted training programs provided by two of the large 

manufacturers of aircraft included in this study and reviewed training materials provided by 

several glass cockpit display manufacturers.

Aircraft Manufacturers

In general, aircraft manufacturers provide transition training for buyers of new aircraft,

and most include training or require that pilots take a training course as part of the purchase 

contract. Manufacturer training includes several components. Written and electronic study 

materials, typically completed by the new owner before arriving at the factory to begin flight 

training, include several hours of familiarization study on aircraft systems, checklists, and 

operating procedures. Ground training and flight training, which generally occur at the factory, 

include 2 to 3 days of instruction, with the possibility of additional instruction if desired. Flight 

and ground training includes takeoffs/landings and flight maneuvers, normal and emergency 

procedures, and aircraft systems and equipment. Pilots who are instrument rated typically also 

practice instrument flying and instrument approaches. NTSB observations and anecdotal reports 

from pilots and instructors suggest that for many general aviation pilots, the transition to new 

avionics requires as much—or often more—effort than the transition to the new aircraft itself. 

Both manufacturers visited by the NTSB incorporated flight training devices and avionics 

simulators into their training to provide additional avionics instruction.

Typical factory training is designed as familiarization training or as a “checkout,” rather 

than as a proficiency evaluation. Persons who complete the course receive a certificate or proof 

of completion that insurance companies accept—and often require—and that can be credited 

toward the FAA’s WINGS pilot proficiency program.71 Factory training typically does not result 

in an endorsement for a flight review or instrument proficiency check,72

 71 See <

but manufacturers will 

provide the additional instruction necessary to complete a flight review or instrument proficiency 

check at additional owner expense. Manufacturers can also arrange to have a flight instructor 

accompany the owner on the flight home in the new aircraft, and most maintain networks of 

training centers and/or factory-trained instructors to provide additional and recurrent training 

throughout the country. Although aircraft manufacturers will provide training to anyone, free 

factory training programs almost exclusively target the original aircraft owner. Some new owners 

choose to allocate the transition training included with the purchase of a new aircraft to local 

flight instructors so that they can continue to receive factory-approved training after returning 

home. Buyers of used aircraft, or other pilots wishing to receive factory-approved training, can 

also purchase training at the factory, but they would typically receive training through the 

https://www.faasafety.gov/WINGS/pppinfo/default.aspx> for an explanation of the FAA Safety Team, 

WINGS pilot proficiency program. 72 See 14 CFR 61.57 for the requirements of the flight review and instrument proficiency check.
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distributed network of training centers or factory-approved instructors. Some aviation insurance 

providers require periodic factory-approved recurrent training or encourage such training through 

discount incentives. 

In some cases, manufacturers and aviation insurance companies have collaborated with 

academic institutions to develop training programs and accident reduction initiatives. In addition 

to the FAA’s FITS program and the training materials and programs currently in place, industry 

efforts are underway to identify new methods for reducing accidents.73

Avionics Manufacturers

Most manufacturers of glass cockpit avionics produce training materials to support their 

products. A common training tool produced by some of the larger avionics manufacturers is a 

software simulator for use on a personal computer that allows pilots to interact with the display 

interface to become familiar with display operation and capabilities, menu organization, and 

control functions. These software simulators are not intended to replicate the functionality of an 

approved flight simulator or training device74

Some glass cockpit avionics manufacturers also produce training curricula and manuals. 

For example, Garmin produces a guide to its cockpit avionics for flight instructors and pilot 

examiners

but rather to serve as interactive procedural 

trainers that allow pilots to practice using glass cockpit avionics and experience various display 

system malfunctions and failures that may not be easily or safely replicated in the aircraft. Some 

avionics manufacturers provide free software simulators, while others charge a small fee but 

provide a free copy with purchase of the avionics equipment.

75 that includes an overview of potential failure modes and operational scenarios that 

correspond to pilot knowledge and performance requirements of the FAA Instrument Rating 

PTS. Garmin also produces a pilot training guide and knowledge test, along with resource 

materials for flight instructors to train and evaluate pilots on the operation of its G1000 glass 

cockpit system.76

Insurance Requirements

Although the FAA currently has no specific training requirements for pilots of light 

aircraft related to aircraft avionics and displays, aviation insurance providers often require pilots 

to complete training to receive and maintain coverage. The NTSB spoke with several aviation 

 73 For example, the Airmanship Education Research Initiative (AERI) is a collaborative research effort by Cirrus 

Design Corporation, Avemco Insurance, and the University of Illinois Urbana-Champaign aimed at identifying methods 

for teaching improved decision-making techniques: <http://www.humanfactors.illinois.edu/news/news.aspx?29>. 74 Title 14 CFR Part 60 and FAA Advisory Circular AC-61-136 provide guidance for the approval of flight 

simulators and training devices for pilot training and certification. 75 Garmin International, Inc., Integrated Flight Deck, Guide for Designated Pilot Examiners and Certificated 

Flight Instructors, 190-00368-02 Revision C, May 2008. (Olathe, Kansas). Available online at:

<http://www8.garmin.com/manuals/G1000:Non-AirframeSpecific_GuideforDPEsandCFIs.pdf>. 76 Garmin International, Inc., Integrated Flight Deck, Pilot’s Training Guide, Instructor’s Reference (-06). 190- 00368-06 Revision B, May 2008 (Olathe, Kansas). See <http://www8.garmin.com/manuals/G1000:NonAirframeSpecific_PilotsTrainingGuide_InstructorsReference-06_.pdf>.
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insurance company representatives and insurance underwriters to better assess the nonregulatory 

training requirements for pilots and owners of glass cockpit-equipped aircraft.

Actuarial data, including claims information and person-specific details, allow insurance 

companies to determine coverage costs and establish tailored training requirements for pilots 

transitioning to glass cockpit aircraft. Insurance companies consider each pilot’s history and 

flight experience, as well as the pilot’s record as a customer with a particular company, when 

establishing requirements for coverage. A private pilot with an instrument rating, 1,000 hours of 

flight time, and no history of major claims may be required to complete factory transition 

training, while a new private pilot who does not hold an instrument rating may be required to 

receive additional initial and/or recurrent factory-approved training beyond the basic transition 

course. Some providers suggested that they may decline coverage to pilots wanting to insure 

high-performance aircraft with glass cockpit avionics unless the pilots were previous customers 

with a good claims history. The exact details of insurance company requirements are tailored to 

individual pilots and vary from one company to the next. However, these requirements are often 

more rigorous than the regulatory requirements that the FAA has established for general aviation 

pilots based on other equipment-specific properties, such as high performance, complexity, or 

conventional landing gear.77

In some cases, however, insurance requirements are not particularly rigorous or do not 

establish additional requirements for pilots transitioning into aircraft with glass cockpit avionics. 

For example, the NTSB spoke with some insurance providers who suggested that they would not 

require additional training for an existing customer upgrading from an older aircraft with 

conventional instruments to a similar new aircraft with glass cockpit displays (for example, from a 

1980 Cessna 172 to a 2006 Cessna 172), but that they would adjust coverage and premiums based 

on the value of the airframe. Other providers said they would require a one-time, 

equipment-specific checkout. With regard to new glass cockpit displays retrofitted to existing 

aircraft, insurance providers said that they typically would not be aware of the new equipment 

unless owners contacted them to increase their coverage, and that in that case, they would be 

unlikely to impose additional requirements for training. Manufacturers and insurance company 

representatives also mentioned that they are aware that in some cases, owners have chosen to 

“self-insure” their aircraft or forgo coverage and assume the responsibility for any problems they 

might encounter.

The lack of equipment-specific training requirements from the FAA and the variability of 

insurance company requirements result in a wide range of initial and recurrent training 

experiences among pilots of glass cockpit aircraft. With the exception of the training provided by 

manufacturers with the purchase of a new aircraft, pilots must currently seek out 

equipment-specific training.

 77 Title 14 CFR 61.31 details requirements for aircraft-specific training required to act as pilot-in-command.
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Chapter 5: Case Study Review

In addition to the data analyses and the assessment of training resources and requirements 

described above, the NTSB reviewed accident investigations involving glass cockpit-equipped 

aircraft to identify cases in which glass cockpit displays either malfunctioned or functioned in a 

manner that was different from a conventional display and/or pilot expectation. This chapter 

discusses those case studies and several issues identified in those reviews.

Pilot Expectations Regarding Glass Cockpit Displays

On April 9, 2007, at 1159 mountain daylight time, a Cirrus Design Corporation SR22, 

N953CD, piloted by a private pilot, sustained substantial damage when it collided with trees 16 

miles north of Luna, New Mexico, following a ballistic parachute deployment.78

The pilot said he was climbing from 15,000 feet to 16,000 feet to avoid building 

thunderstorms and snow showers. The pilot reported that he was in IMC when the airspeed 

indication started to decrease and the airspeed and altimeter readouts on the PFD went to “hash 

marks” (an indication of system malfunction or data loss, which would have appeared on the 

display as red Xs). The pilot stated that he manually overrode the autopilot to initiate a descent 

and turned the pitot heat on. The pilot reported that shortly thereafter, the airspeed indication 

returned. The pilot sensed that he was in a descent and “pulled back” to slow the airplane down,

and the attitude indicator went “haywire.” The terrain warning system activated, and the pilot 

elected to activate the ballistic recovery parachute on the airplane. The airplane impacted trees 

and came to rest inverted at the top of several trees. The empennage separated from the airplane. 

The outboard portion of the right wing was crushed aft and had partially separated. 

The personal 

flight was being conducted under the provisions of 14 CFR Part 91 on an IFR flight plan. The 

pilot was not injured. The cross-country flight originated at Tucson, Arizona, and was en route to 

Englewood, Colorado. 

The pilot’s written statement indicated that the airplane was “getting hit by snow pellets.” 

He stated that he “turned the TKS [supplemental ice protection system] on to maximum and set 

the windshield defroster to its highest setting.” The pilot contacted air traffic control and 

requested another altitude to “get out of the clouds,” as he was “in light icing.” The pilot wrote 

that when he completed a routing change, he noted that the numbers on the airspeed indicator 

were red.79

 78 See DEN07LA082 <

The pilot stated that he “immediately pushed the nose down.” Shortly thereafter, the 

airspeed indication went to “hash marks.” He stated that the “altitude indicator also gave no 

indication of altitude and appeared to have completely failed.” The pilot wrote that a cross-check 

of the backup airspeed indicator showed no readings, and in a followup telephone interview, he 

stated that the event happened so quickly that he did not initially look at the backup airspeed 

http://www.ntsb.gov/ntsb/GenPDF.asp?id=DEN07LA082&rpt=fa>. 79 Numbers changing to red is consistent with the aircraft’s approaching stall speed.
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indicator, but when he did, it was at zero. The pilot also stated that he did not look at either the 

backup altimeter or backup attitude indicator.80

Data recovered from the aircraft PFD indicated that when the airspeed indication decreased 

to zero, internal validity checks in the PFD flagged the pitot data input as “invalid.”81 The 

extracted data further indicated that system logic checks identified the invalid airspeed value as an 

air data computer failure and subsequently flagged all air data parameters as invalid. According to 

the manufacturer, the result would be to replace all air data information on the display: airspeed, 

altitude, and vertical speed with red “X” indications, and outside temperature with dashed lines.

The display operated as designed in this case, but the resulting behavior was different from that of 

conventional cockpit instruments. (If the pitot tube drain remains open, blockage of the pitot tube 

intake will typically result in a decreased or zero airspeed indication on a conventional airspeed 

indicator while the remaining instruments will continue to function normally.) In this case, the PFD 

displayed failure indications for all air data parameters,82

During the investigation of an accident only a few months later, which involved a Piper 

Aircraft PA-46-500TP Meridian equipped with dual PFDs produced by the same avionics 

manufacturer as in the previous accident example, NTSB investigators found similar flagging of 

air data parameters in response to suspected pitot tube intake blockage due to airframe icing.

which led the pilot to initially interpret a 

likely pitot tube intake blockage due to icing to be an air data computer failure.

83

Data recovered from the accident aircraft indicated that the PFD software had also flagged as 

invalid the airspeed, altitude, and vertical speed information as the dynamic pressure sensed by 

the system decreased to zero. In that case, the pilot and copilot PFDs in the accident airplane 

were fed from separate pitot inputs, and the backup airspeed was fed from the pilot’s side pitot 

input. According to the manufacturer,84 blockage of both pitot tube intakes would have resulted 

in loss of all air data on both primary displays and a loss of usable information on the backup 

analog airspeed indicator. The flagged air data would also have resulted in the autopilot 

automatically disengaging with an audible warning.85

Although the PFD displays in these accidents functioned differently than conventional 

displays would have under similar circumstances, they performed in accordance with the 

The Piper Meridian was not equipped with 

a ballistic parachute as was the Cirrus involved in the earlier accident. The accident aircraft 

experienced a loss of control and subsequent in-flight breakup, resulting in fatal injuries to the 

pilot and two passengers.

 80 Refer to the document “Statements” in the NTSB Docket Management System records for accident case 

DEN07LA082. 81 Refer to the flight data recorder group chairman’s factual report in the NTSB Docket Management System 

records for accident case DEN07LA082. 82 The other data parameters affected in this case included altitude and vertical speed. 83 NTSB investigation number CHI07FA183, June 28, 2007. This accident is included here as an example of the 

PFD function, but it was not included in the statistical study analyses because it involved a turboprop-powered 

aircraft. 84 Refer to manufacturer letter dated August 12, 2009, in the NTSB Docket Management System records for 

accident case CHI07FA183. 85 For a complete discussion of system operation, see final accident report in the NTSB Aviation Accident 

Database at <http://www.ntsb.gov/ntsb/GenPDF.asp?id=CHI07FA183&rpt=fa>, as well as the manufacturer and 

FAA correspondence included in the official NTSB docket for this case.
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intended design and software logic. Title 14 CFR 23.1309(b) requires that warning information 

be provided to alert pilots to unsafe operating conditions to enable them to take appropriate 

corrective action, and the requirements of 14 CFR 23.1581 state that an aircraft flight manual 

(AFM)—which must contain information about the safe operation of aircraft systems in the 

event of malfunction—must be furnished for each aircraft. 

Given its concerns about pilots’ need to understand complex aircraft system operation, 

which was established in its 1992 special investigation of several Piper Aircraft model PA-46 

airplane accidents,86

Require the manufacturers of integrated flight guidance and control systems, for which 

supplements to the airplane flight manual and pilots operating handbook must be 

provided, to develop and make available to operators detailed training information that 

will enable pilots to diagnose system failures, understand pilot-induced flight control 

system problems, and use the system in a safe and proficient manner. (A-92-89)

the NTSB issued the following recommendation to the FAA: 

In response to NTSB recommendation A-92-89, the FAA issued Change 1 to AC 23-8A, 

Flight Test Guide for Certification of Part 23 Airplanes, and AC 23.13091B, Equipment, Systems, 

and Installations in Part 23 Airplanes, emphasizing that complex integrated systems may dictate 

that cockpit warning indicators and/or detailed emergency procedures information be included in 

the FAA-approved AFM or AFM Supplement. Based on this action by the FAA, the NTSB 

classified Safety Recommendation A-92-89 “Closed—Acceptable Action” on June 28, 1996.

The AFM Supplement for the PFD installed in the Piper Aircraft Corporation Meridian 

included a full description of a loss of air data computer information, along with guidance to use 

the analog backup instruments in the event of failure. However, the manual did not provide 

specific information about system behavior in response to the loss of specific data inputs, such as 

a pitot tube intake blockage. In response to communication from NTSB investigators, the FAA 

and the avionics manufacturer reviewed this case and determined that flagging all air data 

parameter indications as invalid in response to a loss of pitot input was not ideal. The 

manufacturer agreed to change the functionality in future software revisions, and the FAA agreed 

that a revision would be added to the AFM to better inform pilots of the system functionality 

until the software could be changed.

Equipment Design and Reliability

Like all aircraft systems and equipment installations, glass cockpit displays are subject to 

14 CFR Part 23 requirements for reliability and safety assessment. The reliability of electronic 

PFDs is generally assumed by the FAA and the pilot community to exceed that of their 

conventional analog equivalents due to the mechanical reliability of solid-state systems and the 

additional redundancy often required for electronic systems. For example, guidance provided in 

14 CFR 23.1311—and in the associated AC 23.1311-1B, Installation of Electronic Display in 

 86 Piper Aircraft Corporation PA-46 Malibu/Mirage Accidents/Incident, May 31, 1989, to March 17, 1991, 

Special Investigation Report NTSB/SIR-92/03 (Washington, DC: National Transportation Safety Board, 1992).
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Part 23 Aircraft—specifies that to satisfy the requirements of 14 CFR 23 for IFR flight, 

electronic displays of airspeed, attitude, and altitude information require either dedicated standby 

instruments or dual independent PFDs. Similar redundant instrumentation is not required for 

Part 23 aircraft in order to be certified for IFR flight with conventional analog instruments. The 

general principle guiding this and similar requirements for electronic displays is that the safety, 

workload, and operational consequences of a new technology should be at least as good as the 

equipment it replaces. Manufacturers must provide evidence that the operational reliability 

aspect of this requirement is met during initial certification. Following certification, 

manufacturers must report certain equipment failures to the FAA, and their manufacturing 

processes are subject to inspection by the FAA, but reliability information is generally not 

available outside the manufacturer.87

Human performance objectives of increasing pilot awareness while simultaneously 

reducing workload and error are more difficult to achieve and validate than equipment reliability. 

AC 23.1309-1D addresses this difficulty in section 19(a), Flight Crew and Maintenance Task,

stating that “quantitative assessments of the probabilities of flight crew and maintenance errors 

are not considered reasonable.” The qualitative standard is that crews should respond to 

equipment malfunctions in a timely manner without jeopardizing other safety-related tasks and 

that such a response should not require exceptional skill or strength. 

While arguably difficult to validate, assessments of the interaction between equipment 

design and human performance could greatly improve safety, especially in light of the criticality 

of human/equipment interactions. In its 2006 Safety Report on the Treatment of Safety-Critical 

Systems in Transport Airplanes,

88

Amend the advisory materials associated with 14 CFR 25.1309 to include consideration 

of structural failures and human/airplane system interaction failures in the assessment of 

safety-critical systems. (A-06-37)

the NTSB expressed concern about the failure to consider 

guidance for human performance evaluation of Part 25 aircraft and issued the following 

recommendation to the FAA to consider human/airplane system interactions in the assessment of 

safety-critical systems in transport aircraft certification: 

89

This recommendation was directed at Part 25 aircraft, but human/airplane system 

interaction failures are also a safety concern in Part 23 aircraft. At the time of writing, the FAA is 

reviewing the Part 23 certification process and related guidance. In addition, several FAA ACs

that address avionics systems are currently open for comment, such as AC 23-17C, Systems and 

Equipment Guide for Certification of Part 23 Airplanes and Airships; AC 23.1309-1E, System 

Safety Analysis and Assessment for Part 23 Airplanes; and AC 23.1311-1C, Installation of 

 87 Title 14 CFR 21.3 requires holders of TSO authorization to report certain equipment failures to the FAA, and 

14 CFR 21.615 requires that each manufacturer of equipment under TSO authorization allow the FAA to inspect 

equipment, inspect manufacturing facilities, review technical data files, inspect the manufacturer’s quality control 

system, and observe any equipment tests upon request of the Administrator. However, these activities are typically 

prompted by specific events rather than being part of a continuous review process. 88 Safety Report on the Treatment of Safety-Critical Systems in Transport Airplanes, NTSB/SR-06/02. 

(Washington, DC: National Transportation Safety Board, 2006).

89 As of November 2009, this recommendation was classified “Open—Acceptable Response.” 
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Electronic Display in Part 23 Airplanes. In July 2009, the FAA released its Part 23 - Small 

Airplane Certification Process Study (CPS),90

One area identified in the CPS report as needing greater uniformity was the application of 

good human factors design principles to keep pace with the increasing capabilities and 

complexities of avionics systems. The aviation industry has attempted to develop design 

frameworks and voluntary guidance for the design of glass cockpit avionics,

which included findings and recommendations 

from the FAA and industry groups, such as the AOPA, GAMA, the Experimental Aircraft 

Association, and the National Business Aviation Association. This report, which predicted that 

the introduction of new 14 CFR Part 23 technologies would continue to accelerate over the next 

two decades, went on to recognize increased responsibility on the part of the FAA: “This is good 

news for [general aviation], but it increases the FAA oversight burden. The FAA must develop 

new regulatory, policy and guidance materials to address such technologies.”

91 and the FAA 

includes human performance considerations in its ACs92 and Policy Statements93

Avionics and aircraft systems in Part 23 airplanes are offering more features and 

integration of these features. There is a broad range of system complexities offered in 

Part 23; some intuitive and others non-intuitive for pilots.

for 

certification. Nevertheless, design challenges persist due to the complexity and rapid 

development of display technology. FAA and industry representatives included a finding in the 

CPS report acknowledging the following:

Not all airplane and avionics designers have considered the pilot-machine interface by 

using good human factors practices. General aviation needs airplanes that are intuitive to 

operate, requiring as little training as possible.94

Analyzing Part 23 certification requirements was not within the intended scope of this 

NTSB study, other than to highlight the historic emphasis on equipment reliability—despite an 

acknowledgment of human performance as a leading factor in aviation safety. The approach to 

certification of Part 23 aircraft equipment has implied that human error can be reduced with 

increased use of technology. This approach and the importance placed on avionics technology 

are summarized in AC 23.1309-1D:

 90 U.S. Department of Transportation, Federal Aviation Administration, Part 23 - Small Airplane Certification 

Process Study (Washington, DC: Federal Aviation Administration, July 2009).

91 See for example, GAMA Publication 10 - Recommended Practices and Guidelines for Part 23 Cockpit/Flight 

Deck Design (<http://www.gama.aero/files/gama_publication_10_hf_september_2000_pdf_498cad6edd.pdf>) and 

GAMA Publication 12 - Recommended Practices and Guidelines for an Integrated Cockpit/Flightdeck in a 14 CFR 

Part 23 Airplane <http://www.gama.aero/files/gama_publication_12_p23cockpit_april_2005_pdf_498cadb978.pdf>.

92 FAA AC 23.1311-1B, available online at 

<http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/48bc1051f079b7418625702100639

56c/$FILE/AC23.1311-1B.pdf>.

93 FAA Policy Statement PS-ACE100-2001-004, available online at 

<http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/ad52dc6379f1e4e786256c40004a0128/$FILE/

polmen.pdf>.

94 Finding 5.2.
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For all airplanes, but particularly GA [general aviation] airplanes, pilot decision-making 

causes most accidents. Pilot decision-making accidents, the largest single cause, often are

the result of a lack of situational awareness relative to terrain or weather, or to a loss of 

control due to excess workload. Correct pilot interventions and actions have prevented 

some of these accidents. An increase in avionics equipage rates that improved pilot 

situational awareness or simplify the task had a significant positive impact on the GA 

accident rate.

The text of the AC goes on to cite the AOPA Air Safety Foundation study of TAAs as 

evidence of that positive effect. However, the AC also acknowledges that increased aircraft 

technology must be accompanied by pilot training in that “technologically advanced aircraft has 

delivered multiple safety benefits to GA pilots, but pilot training tied to experience has to evolve 

with it.”

Standardization of Instrument Design and Operation

Unlike glass cockpit displays, the design and operation of conventional flight instruments 

is similar regardless of aircraft or manufacturer. The six instruments that make up a conventional 

cockpit include three pitot/static and three attitude instruments. Pitot/static instruments use 

aneroid capsules, calibrated diaphragms that expand and contract in response to changes in static 

air pressure to provide information about altitude (altimeter and vertical speed indicator) and the 

differential between static and dynamic pressure associated with speed (airspeed indicator). The 

attitude instruments (attitude indicator, heading indicator, and rate-of-turn indictor) use 

vacuum-driven and/or electrically driven gyros to provide information about aircraft orientation. 

Individual manufacturers may vary the design of their instruments or instrument display 

face slightly, but the basic operation is so similar for all Part 23 aircraft that instructional 

materials often explain instrument design and functionality using detailed cutaway views of the 

instruments. Not all pilots may share an equal understanding of the inner workings of analog 

instruments, but the information is readily available in training material. The following sample 

illustration of a conventional airspeed indicator (figure 22) is taken from the FAA’s most recent 

(2007) edition of the Instrument Flying Handbook. 
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Figure 22. Illustration of a conventional airspeed indicator mechanism, adapted from the FAA 

Instrument Flying Handbook.

A similar example of instructional materials for analog instruments can be found in the 

FAA’s newly revised Pilot’s Handbook of Aeronautical Knowledge.95

 95 Federal Aviation Administration, Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25.

The illustrations in 

figure 23 were copied from chapter 7 of that handbook and show the operating and design 

principles at work in the instruments that display attitude and heading information. Like the 

altimeter, the basic design of the analog version of these instruments can be explained using 

cutaway images.
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Figure 23. Illustrations of the internal mechanisms that drive analog attitude and heading 

indicator instruments, copied from the FAA Pilot’s Handbook of Aeronautical Knowledge.

Unlike the relatively simple system of gyros and linkages that drives analog instruments,

very little information is available to pilots about the glass cockpit display equivalent. The

computerized systems at the heart of electronic PFDs are combinations of electronic components 

and software that are both unique to the manufacturer and equipment, and that are subject to 

change with any future system software revision. In contrast to the cutaway illustrations for

analog instruments, illustrations of digital instruments do not lend themselves to the same 

amount of detail. Figure 24, for example, shows an AHRS, which drives the attitude and heading 

indicator displays of a PFD. As this illustration shows, the system is both figuratively and 

literally a “black box.” Although the FAA Pilot’s Handbook of Aeronautical Knowledge includes 

more than five pages of text and illustrations to describe the design and function of the analog 

gyroscopic instruments, it includes only four sentences describing the design of an AHRS. 

Rather than being indicative of an incomplete manual, this difference reflects the nature of the 

design of electronic display systems. 
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Figure 24. Illustration of an AHRS, copied from the FAA Pilot’s Handbook of Aeronautical 

Knowledge.

The FAA summarizes the problem in its inspector handbook as part of the background 

information provided to inspectors regarding FITS acceptance of training courses or materials:

In the past, displays, avionics, and navigation equipment all looked and functioned in a 

similar manner regardless of the manufacturer. This is not the case with today’s advanced 

avionics systems and displays. Training in the operation of one manufacturer’s GPS 

receiver may not give the pilot sufficient knowledge to safely operate another 

manufacturer’s receiver. This is even more evident with full glass cockpits. Not only does 

the functionality of PFDs and MFDs vary between manufacturers, but also due to aircraft 

systems differences, the same avionics equipment in a different type aircraft may 

function differently.96

Interpretation of Equipment Malfunctions

The wide variability in system design has implications for pilots’ ability to identify and 

diagnose system malfunctions. For example, one of the fundamental skills required to fly an 

aircraft by reference to flight instruments is instrument cross-checking. Cross-checking, or 

scanning, refers to the task of comparing information from individual instruments and integrating 

that information into an overall understanding of the aircraft’s orientation and performance. If 

information from one or more instruments does not agree with pilots’ understanding of the 

aircraft attitude or performance, the pilots must rely on an understanding of instrument design 

and operation to reconcile discrepancies while ruling out the possibility of instrument 

malfunction. With conventional cockpit instruments, partially obstructed or blocked pitot tubes 

and static ports, vacuum pump failures, and gyro malfunctions exhibit characteristic symptoms 

 96 FAA Order 8900.1, Flight Standards Information Management System (FSIMS), Issue an FAA Industry 

Training Standards (FITS) Acceptance When Requested by a Flight School, Training Center, or Other Training 

Provider (Vol. 5, Chapter 9, Sec. 5), 5-1669, CNG 0.
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that can be identified by comparing information from all six instruments. Although these 

instruments use common sources of input, the independence between inputs and the redundancy 

among instrument displays are sufficient to enable pilots to diagnose common failure modes. 

Figure 25 is an example of a graphic referenced in questions from the FAA airman instrument 

rating knowledge test in which a pilot applicant must interpret an instrument failure 

identification. A typical knowledge test question associated with this type of graphic would ask 

the pilot applicant to identify the system that has failed and/or determine the corrective action 

necessary to return the airplane to straight-and-level flight. Similar graphics and questions are 

included in the knowledge test, requiring pilots to identify unusual aircraft attitudes and 

determine the corrective action necessary for recovery.

Figure 25. FAA instrument rating knowledge test sample: instrument malfunction interpretation 

(pitot tube intake and drain blockage).

As the pilot of the Luna, New Mexico, accident saw firsthand, however, the task of 

interpreting malfunctions and failures in glass cockpit displays is different than for conventional 

cockpit instruments. Different glass cockpit systems can also behave very differently from one 

another. For example, the pitot tube intake blockage in the system installed in the New Mexico 

accident aircraft resulted in the air data parameters being flagged as invalid. Further, some 

manufacturers of glass cockpit systems use designs that combine both the air data computer and 
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AHRS component functions so that a similar blockage could affect not only the airspeed and 

altitude displays but also the aircraft attitude display.97

Most of the current generation of light aircraft equipped with glass cockpit displays 

includes conventional airspeed, attitude, and altitude instruments as backup in the event of a PFD 

malfunction. These backup instruments typically share the same pitot and static inputs as the 

PFD. In some cases, a single small PFD-like electronic flight display is provided as a backup 

instead of conventional instruments. Due to differences in the design and operation of different 

electronic flight displays, it is possible that the backup display and the primary display will 

respond differently to a loss of data input, and that both will function differently than 

conventional instruments would under the same circumstances.

Equipment-Specific Training 

Problems associated with pilots learning to operate new and complex aircraft systems are 

by no means new, nor are they unique to glass cockpits. On February 3, 1959, a Beechcraft 

Bonanza, N3794N, crashed just after departure from Mason City Municipal Airport, Mason City, 

Iowa. The aircraft collided with terrain in an approximately 90-degree bank, nose-down pitch 

attitude, killing the pilot and three passengers: Charles Hardin, J. P. Richardson, and Richard 

Valenzuela, also known, respectively, as Buddy Holly, The Big Bopper, and Richie Valens.98

The CAB considered the problem serious enough that it included as an attachment to the 

report a Safety Message for Pilots, stating the following in regard to flight instruments:

The 

accident gained a level of notoriety in popular culture because of the celebrity of the passengers 

and subsequent movie and television depictions of the circumstances surrounding the accident. 

Less well known, however, are the findings of the accident investigation. In its final report on the 

accident, the Civil Aeronautics Board (CAB)—predecessor to the NTSB—found the probable 

cause of the accident to be the pilot’s decision to depart into IFR flight conditions when he was 

not qualified to do so. In addition, the pilot’s unfamiliarity with the attitude indicator, which 

provided a pitch display opposite that of the “artificial horizon” to which he was accustomed, 

was found to be a contributing factor to the accident. 

The assumption may be that, providing one is aware of this difference, no difficulty 

should be experienced in utilizing either instrument. This assumption, however, is true 

only if the pilot has had sufficient training on both instruments.

The attachment went on to issue a warning to pilots:

 97 For example, the Airplane Flight Manual Supplement for the Aspen Avionics EFD1000 system (A-01-175-00 

Rev. D) contains a warning that, “Because the EFD1000 uses pitot and static pressures as part of the ADAHRS [Air 

Data Attitude Heading Reference System] solution, loss or corruption of this data, such as from a line blockage, will 

impact the accuracy of data output by the ADAHRS. Affected parameters can include the airspeed, altitude and 

attitude information displayed by the EFD1000. If erroneous pitot or static inputs are detected by the EFD1000, the 

EFD1000 will present a ‘CROSS CHECK ATTITUDE’ annunciation.”

98 Beech Bonanza, N3794N, Mason City, Iowa, February 3, 1959, File No. 2-0001 (Aircraft Accident Report, 

Washington, DC: Civil Aeronautics Board, September 15, 1959).
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KNOW YOUR AIRCRAFT EQUIPMENT, ITS CAPABILITIES AND 

LIMITATIONS. DO NOT RELY UPON ANY EQUIPMENT UNDER 

CIRCUMSTANCES REQUIRING ITS USE FOR THE SAFE CONDUCT OF 

THE FLIGHT UNTIL YOU HAVE ACQUIRED SUFFICIENT EXPERIENCE 

UNDER SIMULATED CONDITIONS TO INSURE YOUR ABILITY TO USE 

IT PROPERLY.” (emphasis included in the original)

Pilots transitioning to glass cockpit-equipped aircraft face a situation similar to that of the 

Mason City accident pilot, but glass cockpit avionics present new and unique challenges for 

flight training that do not apply to conventional round-dial instruments. Rapidly changing 

equipment, the complexity of the systems, and the lack of standardization also increase the 

burden on flight instructors and pilot examiners to maintain their knowledge and proficiency 

with the variety of systems they may encounter when providing instruction. 

The difficulty or inability to simulate various failure modes and functions can limit an 

instructor’s or examiner’s ability to train pilots and evaluate their ability to respond to various 

emergencies or equipment malfunctions. For example, the easiest type of equipment malfunction 

to simulate in a typical glass cockpit aircraft is the failure of a display screen or the associated 

backlighting. This is commonly simulated by decreasing screen brightness until it appears blank. 

In the event of an actual failure, a pilot would transfer functions to the remaining display and 

refer to backup instruments as necessary. It is also possible to simulate the discrete failure of the 

air data computer or AHRS components of some PFDs, depending on the system, by either 

switching off the unit or pulling a circuit breaker. However, a circuit breaker should not be used 

as a switch,99 and pulling a circuit breaker is therefore not an appropriate method of simulating 

failures, even though some avionics manufacturer may suggest the practice.100

 99 For example, FAA Advisory Circulars AC 23-17B and AC 120-80 include guidance stating that a circuit 

breaker (CB) should not be used as a switch. AC 120-80 (page 11-12) states, “Since CBs are designed to open an 

electrical circuit automatically at a predetermined overload of current, they should not be used for day-to-day 

operational functions because they would not be performing their intended function, which is protection against 

overloads. Circuit breakers, even those suitable for frequent operation, should not be used as a switch to turn 

protected items on or off.” 

In aircraft 

equipped with analog gauges, failure of an instrument can be simulated by covering that 

instrument, using static covers designed for the purpose or “sticky notes.” However, the various 

flight data parameters of airspeed, attitude, heading, vertical speed, and altitude are combined on 

a PFD, making partial failures harder to simulate. Display manufacturers recommend against the 

use of sticky notes or static covers because they might harm expensive display screens. Some 

third-party vendors have developed full-screen overlays to simulate various failure modes. 

100 The “Recommendations for Failure Simulation” section (page 17) of Garmin International, Inc., Integrated 

Flight Deck, Guide for Designated Pilot Examiners and Certificated Flight Instructors, 190-00368-02, Revision C, 

May 2008 (Olathe, Kansas) includes instructions for two methods of simulating failures. The instructions state that 

the preferred method is to use the display dimming controls to simulate a display failure and that the other, less 

desirable, method is to pull various circuit breakers. However, the guide subsequently (page 19) notes that Cessna 

does not recommend this practice for its aircraft: “Cessna does not recommend pulling circuit breakers as a means of 

simulating failures on the GIFD [Garmin Integrated Flight Display]. Pulling circuit breakers—or using them as 

switches—has the potential to weaken the circuit breaker to a point at which it may not perform its intended 

function.” The guide also acknowledges that pulling circuit breakers can interfere with the safe operation of other 

equipment.
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In summary, accident records have demonstrated the importance of pilots understanding 

the capabilities and limitations of their aircraft. The nature and complexity of glass cockpit 

displays, and the variety of unique glass cockpit system designs, have created a need for new 

training procedures and tools to ensure that pilots have that understanding.

Tracking Equipment Function and Reliability

The NTSB identified relatively few instrument failures in the set of study accidents that 

involved either conventional or glass cockpit aircraft,101 and the information necessary to compare 

the reliability of conventional and glass displays was not available. In fact, one of the issues 

identified during the review of study accident reports was a lack of information being captured 

about system malfunctions and service difficulties, which could be used to research ways of 

preventing future accidents. One accident citing instrument malfunction in a glass cockpit aircraft 

occurred on January 15, 2005, when a Cirrus Design SR22, N889JB, was destroyed as the result 

of impact with a house and terrain following a loss of control in flight.102

The pilot departed on an IFR flight plan in instrument meteorological flight conditions 

and shortly thereafter, misinterpreted a series of air traffic control instructions. Subsequent 

callouts and responses by the pilot indicated confusion, to the point at which he stated, “I gotta 

get my act together here.” Less than 1 minute later, the pilot reported “avionics problems,” and 

about 40 seconds after that, during his last transmission, he stated that he was “losin’ it.” The 

airplane subsequently descended nose-down, out of clouds, and impacted a house and terrain. 

The certificated 

commercial pilot was fatally injured. 

NTSB investigators were unable to determine the nature of the failure reported by the 

accident pilot due to the severity of impact damage. However, a review of the accident aircraft 

maintenance records identified a history involving several PFD issues. According to aircraft 

maintenance records, the PFD was replaced three times before the accident: first in response to 

an air data failure, then to fix a navigation course indicator failure, and finally in response to an 

AHRS data failure. During the third replacement, maintenance personnel found that the display 

had been replaced again previously―without logbook entry―due to damage to pitot and static 

fittings during installation of an air conditioning system.

The FAA maintains a service difficulty report (SDR) system to collect information about 

aircraft or equipment problems to accomplish the following:

Provide assistance to aircraft owners, operators, maintenance organizations, 

manufacturers, and the Federal Aviation Administration (FAA) in identifying aircraft 

problems encountered during service. The Service Difficulty Program provides for the 

 101 Of those cases with a probable cause published at the time of writing, two accidents in the glass cockpit 

cohort (NTSB case numbers IAD05FA032 and DEN07LA082), and one accident in the conventional cohort (NTSB 

case number MIA06FA050) included reported malfunctions or failures of flight instruments. 102 NTSB case number IAD05FA032.
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collection, organization, analysis, and dissemination of aircraft service information to 

improve service reliability of aeronautical products.

103

Title 14 CFR Parts 121 and 135 include requirements for air carriers to report certain 

aircraft and equipment malfunctions, failures, and maintenance difficulties.104 Title 14 CFR 

Part 125 includes a similar requirement for reporting malfunctions or defects involving large 

aircraft not engaged in common carriage.105

Any other failure, malfunction, or defect in an aircraft that occurs or is detected at any 

time if, in its opinion, the failure, malfunction, or defect has endangered or may endanger

the safe operation of the aircraft.

In addition to the list of specified failures, operators 

are required to report the following: 

Although the SDR system was designed to collect information related to large aircraft, it 

also accepts malfunction and defect reports from light aircraft used in general aviation 

operations. The NTSB has previously identified the need to improve malfunction and defect 

reporting and service difficulty reporting for all aircraft, issuing the following recommendation 

to the FAA in 1993:

Review the reporting items and establish standardized reporting formats for malfunction 

or defect reports and service difficulty reports that include the capability for electronic 

submission. Encourage all operations under 14 CFR Parts 21, 43, 91, 121, 125, 127, 135, 

and 145 to use electronic reporting methods for submission of service difficulty 

information. (A-93-61)106

The NTSB also issued the following recommendation to the FAA to improve malfunction 

and defect reporting for light aircraft and general aviation operations in particular: 

Encourage all persons or organizations that operate under 14 CFR Parts 43 and 91 to 

submit malfunction or defect reports and provide appropriate guidance to improve the 

quality and content of the general aviation service difficulty data base. (A-93-62)107

In response, the FAA published AC 20-109A, providing guidance for use of the SDR 

system by the general aviation community, but the reporting of malfunctions or defects is 

voluntary and not required for general aviation. A search of the FAA’s SDR system found no 

records associated with any of the display failures or the installation damage event involving 

N889JB. 

The FAA’s Part 23 CPS report included a finding highlighting under-use of the SDR 

system by general aviation maintenance personnel as a continuing problem.

108

 103 FAA Advisory Circular 20-109A.

The report 

104 Title 14 CFR 121.703 and 135.415, respectively. 105 Part 125 applies to aircraft with a seating capacity of 20 or more passengers or maximum payload capacity of 

6,000 pounds or more when common carriage is not involved. 106 Closed in 2006, “Unacceptable Action.” 107 Closed in 1994, “Acceptable Action.” 108 Finding 4.4 of the FAA CPS Report.
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included five recommendations to improve SDR reporting for 14 CFR Part 23 aircraft, covering 

issues such as improving maintenance personnel training requirements, communication with the 

aviation community about the SDR system, and the usability and functionality of the SDR 

database.

In addition to collecting voluntary failure, malfunction, or defect reports from operators, 

owners, and maintenance personnel, the FAA requires manufacturers to report certain types of 

equipment failures. In accordance with 14 CFR 21.3, holders of FAA type certificates, 

supplemental type certificates, parts manufacturer approvals, or technical standard order (TSO) 

authorizations are required to report to the FAA any failure, malfunction, or defect in any 

product, part, process, or article manufactured that may result in “failure or malfunction of more 

than one attitude, airspeed, or altitude instrument during a given operation of the aircraft.” In a 

typical scenario, a pilot experiencing an equipment malfunction or failure would report the 

problem to a maintenance facility for repair. The manufacturer would then be notified of the 

problem through a warranty claim or an order for repair or replacement of the affected 

equipment. A manufacturer who determines that the problem involves a failure, malfunction, or 

defect outlined in 14 CFR 21.3 must notify the FAA through the appropriate Directorate Aircraft 

Certification Office. That report must include specific details of the aircraft and equipment 

involved and the nature of the failure. FAA Order 8150.1B regarding the TSO program explains 

that the Aircraft Certification Office will work with the manufacturer to determine the need for 

corrective action.

The failure, malfunction, and defect reporting requirements for manufacturers under 

14 CFR 21.3 are limited to a specific set of circumstances, and problems similar to those 

experienced by N889JB prior to the January 15, 2005, accident would likely not result in a 

manufacturer’s report to the FAA. An additional requirement under 14 CFR 21.3(e) states the 

following:

Whenever the investigation of an accident or service difficulty report shows that an 

article manufactured under a TSO authorization is unsafe because of a manufacturing or 

design defect, the manufacturer shall, upon request of the Administrator, report to the 

Administrator the results of its investigation and any action taken or proposed by the 

manufacturer to correct that defect. If action is required to correct the defect in existing 

articles, the manufacturer shall submit the data necessary for the issuance of an 

appropriate airworthiness directive to the Manager of the Aircraft Certification Office for 

the geographic area of the FAA regional office in the region in which it is located.

In summary, NTSB accident investigations have identified cases in which system 

malfunctions and service difficulties with glass cockpit equipment were not captured in a 

systematic way prior to an accident. FAA requires equipment manufacturers to report specific 

failures and malfunctions and allows for voluntary reports to its SDR system of malfunctions and 

defects affecting light aircraft. However, the reported underutilization of the SDR system for 

reporting of problems associated with light aircraft leaves accident and incident investigation as the 

only publicly accessible means of identifying many types of equipment malfunctions and defects.
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Chapter 6: Data Recording in Glass Cockpit 

Avionics

One of the biggest changes associated with the introduction of glass cockpit displays in 

light aircraft is the capability for onboard recording of flight parameters and system information. 

The software-based systems that drive glass cockpit displays and their internal memory provide 

recording capabilities previously available only to large aircraft with dedicated flight data 

recorders. 

On August 21, 2006, about 1341 eastern daylight time, a Cirrus SR22-GTS, N518SR, 

experienced an in-flight loss of aircraft control during cruise flight near McRae, Georgia. The 

personal flight was operated under the provisions of 14 CFR Part 91 under visual flight rules 

(VFR). Neither the private pilot nor the two passengers were injured, but the airplane was 

substantially damaged by aerodynamic forces. 

The pilot stated that the aircraft “encountered clear air turbulence ... bounced once, and 

then after losing altitude, hit a very hard bounce of severe turbulence.” After stabilizing the 

airplane, the pilot noticed thin lines of paint missing from the top of the right wing. The pilot 

slowed the plane and landed at the nearest airport with no issues. The pilot contacted the 

manufacturer regarding the occurrence, and after examining the airplane, the manufacturer 

contacted the NTSB to report that the aircraft had sustained substantial damage.

This case initially generated interest because it involved a relatively new and popular 

airframe. Structural damage to the extent sustained by the accident aircraft would not be 

expected to result from a transient turbulence encounter. Had this event involved an aircraft 

equipped with a conventional cockpit, the investigation would have had to rely on analysis of the 

airframe structure and materials to estimate the forces encountered. However, the glass cockpit 

avionics in this aircraft provided additional information critical to understanding the event.

The Avidyne PFD installed in the accident aircraft contains flash memory that stores 

information processed by the unit to generate the various flight data displays. The PFD software 

includes a data logging function used by the manufacturer for maintenance and diagnostics. 

Working with the manufacturer, NTSB investigators were able to retrieve data recorded in the 

PFD from the AHRS, such as pitch, roll, heading, and accelerations, and by the air data 

computer, such as pressure altitude, indicated airspeed, and vertical speed recorded during the 

accident flight. The information recorded by the flight displays provided an entirely different 

description of the accident event than that described in the pilot’s initial report. 

Recorded data indicated that the airplane actually climbed to 15,400 feet above mean sea 

level, nearly 17,500 feet density altitude, which was the maximum operating altitude for the 

airplane. The airplane then slowed, stalled, and began a rapid descent, losing 13,000 feet of 

altitude in about 40 seconds before recovering. During the dive, the aircraft experienced several 

positive and negative pitch excursions (+50 to -80 degrees), rolled to the right about its 
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longitudinal axis through two complete 360-degree revolutions, and started a third roll before 

recovering to straight-and-level flight. The airspeed increased from a low of 72 knots at the start 

of the dive to a maximum of about 336 knots indicated—135 knots (about 67 percent) above its 

published maximum limit.109 During recovery, the airplane sustained a positive loading of at 

least 4.733 vertical Gs,110 with an average of more than 4 Gs vertical loading for more than 20 

seconds.111

During interviews with the NTSB investigator-in-charge of this accident, the pilot stated 

that he did not use oxygen during the flight. The NTSB’s medical officer reviewed the 

circumstances of this event and determined that the sustained G-loading experienced by the pilot 

would likely have resulted in G-induced loss of consciousness (G-LOC) or near-loss of 

consciousness. The NTSB’s medical officer determined further that the pilot’s apparent failure to 

accurately recall the events of the flight most likely resulted from the confusion associated with 

hypoxia and the subsequent confusion and amnesia associated with G-LOC or near G-LOC.

Data recovered from PFDs and MFDs have significantly changed the understanding of 

other accident events. An example is the April 9, 2007, Cirrus accident near Luna, New Mexico, 

described in chapter 5 of this report. The pilot initially reported that the accident resulted from a 

PFD failure. Only after review of data recovered from the aircraft PFD and MFD was the 

mismatch between equipment function and pilot expectation understood. 

Another example involved a Piper aircraft model PA-44-180 operated by the University 

of North Dakota on a VFR night cross-country flight.112

 109 The aircraft pilot operating handbook specifies a maximum never exceed speed (Vne) of 201 knots indicated 

airspeed.

On October 23, 2007, about 2212 

central daylight time, the twin-engine PA-44-180, N327ND, was substantially damaged during 

an in-flight collision with terrain near Browerville, Minnesota. The accident pilot and flight 

instructor were fatally injured. With no additional information, this accident could well have 

been assumed to have been the result of crew disorientation or loss of control at night. However, 

data recovered from the aircraft PFD indicated that during cruise flight, the aircraft experienced 

an abrupt departure from controlled flight in both roll and pitch. Subsequent microscopic 

examination and DNA testing by forensic ornithologists identified material recovered from the 

wing skin section as remains of a Canada goose. As a result, investigators determined that a bird 

strike resulted in damage to the aircraft’s left stabilator, causing the airplane to become 

uncontrollable. Based on the findings of this investigation, the University of North Dakota 

provided additional training to its pilots and instructors regarding bird strike hazards and

recommended procedures for reducing the probability of bird strikes during night cross-country 

flights.

110 The PFD unit is limited to recording a vertical G-loading of 4.733 Gs even though the actual Gs loading may 

have been higher. 111 For a detailed description of the recorded data, refer to Specialist’s Factual Report of Recorded Cockpit 

Display Data for NTSB case ATL06LA134 in the NTSB Docket Management System. 112 NTSB investigation number CHI08FA027: this accident is included here as an example of glass cockpit data 

recording, but it was not included in the statistical study analyses because it involved a twin-engine aircraft.
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Prior to the advent of PFDs and the availability of recorded information, techniques used 

to collect information from flight instruments during general aviation accident investigations 

were often limited to analysis of witness marks from needles striking instrument faceplates and 

inspection of internal instrument components. Investigators were similarly limited to the analysis 

of physical evidence of ground scars, witness marks on flight instruments, postaccident engine 

tests, and aircraft wreckage when determining details of an aircraft accident or assessing aircraft 

performance prior to an accident. In contrast, software-driven systems typically leave no physical 

evidence of their performance but do allow for the recording of digital flight information that 

was previously limited to dedicated flight data recorders in large aircraft, enabling investigators 

to review aircraft and engine performance data from the flight. 
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Chapter 7: Discussion

This study set out to assess the safety effect of advanced avionics capabilities on general 

aviation accident rates. To that end, the study compared the operational and accident history of 

two selected aircraft cohorts, one with conventional flight displays and the other with glass 

cockpit primary displays. Study analyses identified several differences in the activity and 

accident records of these two groups of aircraft.

Accident Involvement and Accident Rates

Study analyses showed that glass cockpit-equipped aircraft experienced proportionately 

fewer total accidents than a comparable group of aircraft with conventional round-dial 

instruments. The 2007 AOPA report, Technically Advanced Aircraft: Safety and Training,

included similar findings—that is, that fewer glass cockpit aircraft were involved in accidents 

than would be expected, given the percentage of the aircraft fleet they represent. However, unlike 

the NTSB analyses, which showed that glass cockpit aircraft had a proportionately higher 

number of fatal accidents than their numbers would indicate, the AOPA study found that glass 

cockpit aircraft experienced a proportionately lower number of fatal accidents. Differences in the 

results are due in part to differences in the methodologies of the two studies: while the AOPA 

study made comparisons throughout general aviation as a whole, the NTSB study limited its 

comparisons to a defined group of glass cockpit aircraft and a cohort of the same makes/models 

of aircraft with conventional instruments to reduce the potential for confounds associated with 

comparing aircraft of different age and capability. The NTSB study also used survey data to 

make additional comparisons between aircraft using activity-based accident rates that reflect 

accident risk.

The fact that the rate of total accidents observed for conventionally equipped aircraft was 

higher than that of the glass cockpit aircraft would suggest a safety benefit resulting from the

new technology—if it were not for the glass cockpit cohort’s significantly higher percentage of 

fatal accidents during the years 2002 through 2008 and the higher fatal accident rate observed for 

the cohort in 2006 and 2007. Activity and usage data from the FAA’s GAATAA Survey 

confirmed that differences in the activity of the two cohort groups were likely to influence the 

type and severity of accidents involving the aircraft in each group.

When considered as a whole, the results describe two distinct aircraft operational profiles. 

Aircraft with conventional cockpit displays were more likely to be used for flight instruction. 

Accordingly, these aircraft were also found to have flown more hours per aircraft113 although 

they were used for shorter flights114 and flew less time in instrument conditions.115

 113 Based on 2006 and 2007 GAATAA Survey data.

As a result, 

aircraft in the conventional group were involved in more accidents during takeoffs and landings, 

114 Based on statistical comparisons of accident flights. 115 Based on 2006 and 2007 GAATAA Survey data and statistical comparisons of accident flights.
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which often resulted in less severe outcomes, most likely due to the relatively low speeds during 

those phases and the resulting low impact forces. 

Conversely, the operational profile of glass cockpit-equipped aircraft was found to 

involve fewer flight hours per year but longer trips. Consequently, the glass cockpit-equipped 

aircraft reportedly spent more time than conventional aircraft operating on instrument flight 

plans. The accident record is consistent with the way the aircraft were reportedly used. Glass 

cockpit aircraft experienced more accidents while on long trips and in IMC but also reported 

spending more time operating in instrument conditions. 

Previous NTSB research has identified a higher risk of aircraft on longer flights being 

involved in weather-related accidents and has noted that accidents occurring in IMC are more 

likely to be fatal due to the event profiles and impact forces typically associated with such

accidents.116

Although the study analyses provided clear evidence of a difference in operational 

profiles, they did not reveal whether aircraft owners chose to purchase glass cockpit-equipped 

aircraft because they wanted the increased capabilities to support the type of flight operations 

they engaged in, or if the increased capabilities of their new aircraft encouraged them to conduct 

longer flights and/or fly in more adverse conditions. Pilot motivation and perception of the 

capabilities of their aircraft influence the risks they are willing to accept. Additional research is 

warranted to better understand how pilots of light aircraft perceive glass cockpit displays and 

how those perceptions influence safety. However, based on the pattern of study results, the 

NTSB concludes that study analyses of aircraft accident and activity data showed a decrease in 

total accident rates but an increase in fatal accident rates for the selected group of glass cockpit 

aircraft when compared to similar conventionally equipped aircraft during the study period. 

Overall, study analyses did not show a significant improvement in safety for the glass cockpit 

study group.

The higher number of hours flown during long trips or in IMC results in increased 

exposure to the risks associated with those circumstances, but a comparison of activity-based 

accident rates would be expected to reveal similar rates for both cockpit configurations if the 

underlying accident risk were similar. The glass cockpit cohort instead experienced higher fatal 

accident rates and higher accident rates in IMC than the conventional aircraft—despite the fact 

that the pilots had higher levels of certification, were more likely to be instrument rated, had 

more total flight experience, and had more experience in the aircraft type. 

Safety Issues

Training Resources and Requirements

The study included reviews of training resources, requirements, and initiatives indicative 

of the FAA’s efforts to address the needs of pilots transitioning to glass cockpit aircraft. Despite 

 116 Risk Factors Associated with Weather-Related General Aviation Accidents, Aviation Safety Study 

NTSB/SS-05/01 (Washington, DC: National Transportation Safety Board, 2005.)
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these efforts on the part of the FAA, the NTSB did identify several safety issues and areas for 

improvement during the course of the study.

A review of training resources and requirements showed that the FAA has been updating 

its training materials and PTS in response to the introduction of glass cockpit displays in Part 23 

aircraft. However, FAA airman knowledge tests, such as those required for the Private Pilot 

Certificate, Commercial Pilot Certificate, and Instrument Rating, do not currently assess pilots’ 

knowledge of glass cockpit displays. The NTSB concludes that pilots must be able to 

demonstrate a minimum knowledge of primary aircraft flight instruments and displays in order to 

be prepared to safely operate aircraft equipped with those systems, which is necessary for all 

aircraft but is not currently addressed by FAA knowledge tests for glass cockpit displays. 

Therefore, the NTSB recommends that the FAA revise airman knowledge tests to include 

questions regarding electronic flight and navigation displays, including normal operations, 

limitations, and the interpretation of malfunctions and aircraft attitudes.

A review of the FAA’s training initiatives showed that the FAA worked with 

representatives from the general aviation industry and academia to develop its FITS initiative in 

response to a recognized need for improved training for advanced aircraft systems. Initial 

planning documents show that the FITS initiative intended to combine teaching techniques, such 

as scenario-based training, with requirements for equipment-specific training. The FAA is now 

incorporating scenario-based training and pilot decision-making tools, but to date it has not 

implemented the equipment-specific training requirements suggested in the original FITS 

program documents. Rather, the FAA has recognized several factory and national training 

provider programs as being “FITS accepted.” This study relied on a retrospective review of 

accident records that did not allow for detailed comparisons of the training history of all accident 

pilots, but a review of manufacturer training programs suggests that they primarily benefit the 

first owner (purchaser) of a new aircraft or pilots who seek out such training. In some cases, 

insurance companies may require pilots to receive equipment-specific transition and/or recurrent 

training, but those requirements are neither uniformly nor universally applied. Further, some 

aircraft owners may avoid insurance requirements by choosing to self-insure their aircraft. The 

lack of FAA training requirements and the variability of nonregulatory training requirements and 

programs suggest that additional equipment-specific training requirements are necessary to 

ensure that all pilots of glass cockpit-equipped aircraft possess the knowledge and skill necessary 

to operate their aircraft safely.

Providing Pilots with Information about Display Operation and Limitations

The study considered several accident case studies that highlighted the complexity and 

unique functionality of glass cockpit displays in comparison to conventional instruments, as well 

as potential safety-critical issues associated with the design and operation of software-based 

systems. The case studies illustrate the importance of pilots’ receiving sufficient information 

about system operations and limitations so that they are prepared to identify and safely respond 

to system malfunctions and failures.
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The functions of conventional instruments can be replicated in many ways using solidstate systems, and manufacturers have developed unique designs of pressure transducers, 

specially mounted gyros, accelerometers, and magnetometers controlled by proprietary software. 

The wide variety of complex glass cockpit equipment designs, and their proprietary technology, 

demands that any discussion of these displays be system-specific. Consequently, as electronic 

systems replace analog gauges, the expectation that average general aviation pilots will 

understand the inner workings of their cockpit instruments is no longer realistic. This problem is 

compounded by the fact that, unlike analog gauges, the functionality and capability of electronic 

display systems can continue to evolve after they are installed because of subsequent software 

revisions. The resulting increase in system complexity burdens pilots with the need to keep up 

with changes so that they can understand their avionics systems well enough to identify and 

troubleshoot any abnormal system operations or malfunctions that they might encounter in flight. 

An additional difficulty is that, in comparison to the detailed information included in FAA 

training handbooks about conventional flight instruments, the information about glass cockpits is 

currently limited to very general descriptions of system components and displays.

In addition, as the pilot of the Luna, New Mexico, accident aircraft found, glass cockpit 

displays may function differently than conventional displays under certain conditions. In that 

case, a blocked pitot tube intake that would have affected only the airspeed indicator of a 

conventional cockpit display resulted in loss of airspeed, altitude, and rate-of-climb information 

in a glass cockpit display. The information provided to the pilot indicated only that the air data 

computer had failed, with no indication of why it had failed or whether the situation could be 

safely corrected in flight. The NTSB concludes that pilots are not always provided all of the 

information necessary to adequately understand the unique operational and functional details of 

the primary flight displays in their airplanes. Therefore, the NTSB recommends that the FAA 

require all manufacturers of certified electronic PFDs to include information in their approved 

AFM and pilot’s operating handbook supplements regarding abnormal equipment operation or 

malfunction due to subsystem and input malfunctions, including but not limited to pitot and/or 

static system blockages, magnetic sensor malfunctions, and attitude-heading reference system 

alignment failures.

Equipment-Specific Training Requirements

Integrated electronic displays have the potential to increase the safety of general aviation 

aircraft operations by providing pilots with more operational and safety-related information and 

functionality. For that potential to be realized, however, the burden of responsibility falls on 

pilots to operate the equipment safely and efficiently. Any deficiencies or inefficiencies in 

equipment functionality and interface design must be addressed through superior pilot training 

and skill. 

As aircraft equipment becomes more complex, the demands placed on pilots to manage 

and monitor equipment operation will continue to increase. FAA Part 23 - Certification Process 

Study Report117

 117 FAA, July 2009.

findings and comments included in pertinent draft FAA ACs suggest that the 
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human-equipment interaction issues previously identified for Part 25 transport-category aircraft 

will become increasingly critical for Part 23 aircraft. In contrast to the generalized training 

traditionally required to operate the relatively simple systems in Part 23 aircraft, the complexity 

and variation of Part 25 aircraft systems have been addressed by requiring pilots to hold a type 

rating to act as pilot-in-command.118

Equipment Malfunction Training

However, now that light aircraft are incorporating 

integrated glass cockpit avionics that rival in complexity those in Part 25 aircraft, generalized

systems training may not be sufficient for pilots of these aircraft. Different system architectures 

require different operating techniques, and responses to failure and knowledge of one type of 

glass cockpit display are not likely to transfer to other systems. The NTSB concludes that 

generalized guidance and training are no longer sufficient to prepare pilots to safely operate glass 

cockpit avionics; effective pilot instruction and evaluation must be tailored to specific

equipment. Therefore, the NTSB recommends that the FAA incorporate training elements 

regarding electronic PFDs into its training materials and aeronautical knowledge requirements 

for all pilots. The NTSB also recommends that the FAA incorporate training elements regarding 

electronic primary flight displays into its initial and recurrent flight proficiency requirements for 

pilots of 14 CFR Part 23 certified aircraft equipped with those systems that address variations in 

equipment design and operation of such displays. 

Although PFD screen failure is easy to simulate in a training environment, the accident 

case studies cited in this safety study suggest that screen failure may not be the most likely type 

of glass cockpit failure or abnormal operation that a pilot will encounter. That is, training pilots 

to fly by backup instruments when faced with a blank primary display may not adequately 

prepare them to respond to a partial failure in which they are likely to see a compelling display 

that is presenting erroneous or incomplete data. To be adequately prepared to respond to flight 

instrument system malfunctions and failures, pilots should be trained to identify and respond to 

all anticipated failure modes. However, in many cases, it is neither appropriate nor practical to 

train for all anticipated types of glass cockpit avionics failures and malfunctions in the aircraft. 

The NTSB concludes that simulators or procedural trainers are the most practical alternative 

means of training pilots to identify and respond to glass cockpit avionics failures and 

malfunctions that cannot be easily or safely replicated in light aircraft. Pilots who do not have 

ready access to approved flight simulators or training devices could benefit from 

equipment-specific training using software applications or procedural trainers that replicate glass 

cockpit displays. Therefore, the NTSB recommends that the FAA develop and publish guidance 

for the use of equipment-specific electronic avionics display simulators and procedural trainers 

that do not meet the definition of flight simulation training devices prescribed in 14 CFR Part 60 

to support equipment-specific pilot training requirements. 

 118 Title 14 CFR 61.31.
NTSB Aviation Safety Study

69

Tracking Service Difficulties and Equipment Malfunctions 

NTSB investigations have revealed multiple instances of glass cockpit avionics

malfunctions that were not required to be reported to the FAA and that did not result in an SDR 

system report. Findings of the FAA Part 23 - Small Airplane Certification Process Study suggest 

a general difficulty with tracking Part 23 equipment performance due to SDR system 

underreporting for light aircraft. The NTSB concludes that identification and tracking of service 

difficulties, equipment malfunctions or failures, abnormal operations, and other safety issues will 

be increasingly important as light aircraft avionics systems and equipment continue to increase in 

complexity and variation of design, and current reporting to the FAA’s SDR system does not 

adequately capture this information for 14 CFR Part 23 certified aircraft used in general aviation 

operations. The NTSB also concludes that the FAA’s current review of the 14 CFR Part 23 

certification process provides an opportunity to improve upon deficiencies in the reporting of 

equipment malfunctions and defects identified by the FAA and aviation industry representatives 

in the July 2009 Part 23 - Small Airplane Certification Process Study. 

However, the review of 14 CFR Part 23 and resulting regulatory actions will likely 

require considerable time. Therefore, to improve the voluntary submissions to the FAA SDR 

system in the interim, the NTSB recommends that the FAA inform aircraft and avionics 

maintenance technicians about the critical role of voluntary SDR system reports involving 

malfunctions or defects associated with electronic primary flight, navigation, and control systems 

in 14 CFR Part 23 certified aircraft used in general aviation operations.

Despite the identified problems associated with tracking the function and reliability of 

glass cockpit displays in Part 23 aircraft, the technology has provided a new potential source of 

safety information. The NTSB concludes that some glass cockpit displays include recording 

capabilities that have significantly benefited accident investigations and provide the general 

aviation community with the ability to improve equipment reliability and the safety and 

efficiency of aircraft operations through data analyses.
NTSB Aviation Safety Study

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Summary

This study used manufacturer records, aircraft investigation information, and a tailored 

subset of general aviation activity survey data to assess how the transition to electronic PFD 

avionics has affected the safety of light aircraft. The study also evaluated the resources and 

requirements supporting the transition to this new technology. The results of this study suggest 

that, for the aircraft and time period studied, the introduction of glass cockpit PFDs has not yet 

resulted in the anticipated improvement in safety when compared to similar aircraft with 

conventional instruments. Advanced avionics and electronic displays can increase the safety 

potential of general aviation aircraft operations by providing pilots with more operational and 

safety-related information and functionality, but more effort is needed to ensure that pilots are 

prepared to realize that potential. The FAA, manufacturers, aviation industry groups, and 

academia have an established history of collaboration through the FITS program initiative for 

supporting aircraft model-specific and scenario-based training techniques that would teach pilots 

“higher-order thinking skills.” However, the FAA has changed the focus of the FITS initiative 

and has to date relied on manufacturers and commercial vendors to deliver the 

equipment-specific training originally envisioned for FITS. Adoption of uniform 

equipment-specific training elements by the FAA to ensure pilots have adequate knowledge of 

aircraft equipment operation and malfunctions, as well as improved reporting of equipment 

malfunctions and service difficulties, is likely to improve the safety of general aviation 

operations beyond those involving aircraft with glass cockpit displays. However, such actions are 

particularly important in order to achieve the potential safety benefits associated with advanced 

cockpit technologies in light aircraft.
NTSB Aviation Safety Study

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Conclusions

Findings

1. Study analyses of aircraft accident and activity data showed a decrease in total accident rates 

but an increase in fatal accident rates for the selected group of glass cockpit aircraft when 

compared to similar conventionally equipped aircraft during the study period. Overall, study 

analyses did not show a significant improvement in safety for the glass cockpit study group.

2. Pilots must be able to demonstrate a minimum knowledge of primary aircraft flight 

instruments and displays in order to be prepared to safely operate aircraft equipped with 

those systems, which is necessary for all aircraft but is not currently addressed by Federal 

Aviation Administration knowledge tests for glass cockpit displays.

3. Pilots are not always provided all of the information necessary to adequately understand the 

unique operational and functional details of the primary flight instruments in their airplanes. 

4. Generalized guidance and training are no longer sufficient to prepare pilots to safely operate 

glass cockpit avionics; effective pilot instruction and evaluation must be tailored to specific 

equipment.

5. Simulators or procedural trainers are the most practical alternative means of training pilots to 

identify and respond to glass cockpit avionics failures and malfunctions that cannot be easily 

or safely replicated in light aircraft. 

6. Identification and tracking of service difficulties, equipment malfunctions or failures, 

abnormal operations, and other safety issues will be increasingly important as light aircraft 

avionics systems and equipment continue to increase in complexity and variation of design, 

and current reporting to the Federal Aviation Administration’s service difficulty reporting 

system does not adequately capture this information for 14 Code of Federal Regulations Part 

23 certified aircraft used in general aviation operations.

7. The Federal Aviation Administration’s current review of the 14 Code of Federal Regulations

Part 23 certification process provides an opportunity to improve upon deficiencies in the 

reporting of equipment malfunctions and defects identified by the Federal Aviation 

Administration and aviation industry representatives in the July 2009 Part 23 - Small 

Airplane Certification Process Study.

8. Some glass cockpit displays include recording capabilities that have significantly benefited 

accident investigations and provide the general aviation community with the ability to 

improve equipment reliability and the safety and efficiency of aircraft operations through 

data analyses.
NTSB Aviation Safety Study

72

Recommendations

As a result of this safety study, the National Transportation Safety Board makes the 

following recommendations to the Federal Aviation Administration: 

Revise airman knowledge tests to include questions regarding electronic flight 

and navigation displays, including normal operations, limitations, and the 

interpretation of malfunctions and aircraft attitudes. (A-10-36) 

Require all manufacturers of certified electronic primary flight displays to include 

information in their approved aircraft flight manual and pilot’s operating 

handbook supplements regarding abnormal equipment operation or malfunction 

due to subsystem and input malfunctions, including but not limited to pitot and/or 

static system blockages, magnetic sensor malfunctions, and attitude-heading 

reference system alignment failures. (A-10-37) 

Incorporate training elements regarding electronic primary flight displays into

your training materials and aeronautical knowledge requirements for all pilots.

(A-10-38)

Incorporate training elements regarding electronic primary flight displays into 

your initial and recurrent flight proficiency requirements for pilots of 14 Code of 

Regulations Part 23 certified aircraft equipped with those systems that address 

variations in equipment design and operation of such displays. (A-10-39)

Develop and publish guidance for the use of equipment-specific electronic 

avionics display simulators and procedural trainers that do not meet the definition 

of flight simulation training devices prescribed in 14 Code of Federal Regulations 

Part 60 to support equipment-specific pilot training requirements. (A-10-40) 

Inform aircraft and avionics maintenance technicians about the critical role of 

voluntary service difficulty reporting system reports involving malfunctions or 

defects associated with electronic primary flight, navigation, and control systems 

in 14 Code of Federal Regulations Part 23 certified aircraft used in general 

aviation operations. (A-10-41)
NTSB Aviation Safety Study

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BY THE NATIONAL TRANSPORTATION SAFETY BOARD 

DEBORAH A.P. HERSMAN ROBERT L. SUMWALT 

Chairman Member 

CHRISTOPHER A. HART

Vice Chairman 

Adopted: March 9, 2010
NTSB Aviation Safety Study

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Appendix: Study Accidents

ntsb_no ev_date Registration Make Model Glass Severity

ANC06CA036 24-Mar-06 N514ER Cessna Aircraft Company 172 Conventional NonFatal

ANC06CA114 12-Aug-06 N2469U Cessna Aircraft Company 172 Glass cockpit NonFatal

ATL03LA022 3-Dec-02 N289HG Piper Aircraft, Inc. PA-28-161 Conventional NonFatal

ATL03LA034 11-Jan-03 N5199H Cessna Aircraft Company 172 Conventional NonFatal

ATL04FA096 19-Apr-04 N8157J Cirrus Design Corporation SR20 Glass cockpit Fatal

ATL04LA060 27-Dec-03 N742CD Cirrus Design Corporation SR22 Conventional NonFatal

ATL04LA140 24-Jun-04 N2116P Cessna Aircraft Company 172 Conventional NonFatal

ATL04LA143 20-Jul-04 N2069S Cessna Aircraft Company 172 Conventional NonFatal

ATL04WA042 12-Oct-03 N100BR Cirrus Design Corporation SR22 Conventional Fatal

ATL05CA153 24-Aug-05 N21670 Cessna Aircraft Company 172 Conventional NonFatal

ATL05CA160 10-Sep-05 N1251C Cessna Aircraft Company 182 Glass cockpit NonFatal

ATL05FA034 9-Dec-04 N42SE Diamond Aircraft DA40 Conventional Fatal

ATL05LA105 20-Jun-05 N53538 Cessna Aircraft Company 182 Conventional Fatal

ATL05LA156 31-Aug-05 N5213M Cessna Aircraft Company 172 Conventional NonFatal

ATL06CA068 16-Apr-06 N21527 Cessna Aircraft Company 172 Conventional NonFatal

ATL06CA089 6-Jun-06 N1046P Mooney M20 Glass cockpit NonFatal

ATL06CA117 3-Aug-06 N124CK Cessna Aircraft Company 172 Conventional NonFatal

ATL06FA029 29-Dec-05 N799TM Cirrus Design Corporation SR22 Glass cockpit Fatal

ATL06LA035 13-Jan-06 N87HK Cirrus Design Corporation SR22 Conventional NonFatal

ATL06LA058 31-Mar-06 N2157V Cessna Aircraft Company 182 Conventional NonFatal

ATL06LA134 21-Aug-06 N518SR Cirrus Design Corporation SR22 Glass cockpit NonFatal

ATL07CA035 28-Jan-07 N221GW Cirrus Design Corporation SR22 Conventional NonFatal

ATL07CA047 5-Mar-07 N2145T Cessna Aircraft Company 172 Conventional NonFatal

ATL07CA049 11-Mar-07 N313L Cirrus Design Corporation SR22 Glass cockpit NonFatal

ATL07CA093 15-Jun-07 N2228L Cessna Aircraft Company 172 Glass cockpit NonFatal

ATL07CA105 15-Jul-07 N13151 Cessna Aircraft Company 172 Glass cockpit NonFatal

ATL07FA010 22-Oct-06 N2135L Cessna Aircraft Company 182 Glass cockpit Fatal

ATL07LA041 9-Feb-07 N315P Hawker Beechcraft 36 Conventional NonFatal

ATL07LA115 17-Aug-07 N869CD Cirrus Design Corporation SR20 Glass cockpit NonFatal

CEN09CA002 3-Oct-08 N5172J Cessna Aircraft Company 172 Conventional NonFatal

CEN09CA020 11-Oct-08 N764C Piper Aircraft, Inc. PA-28-181 Conventional NonFatal

CEN09CA049 3-Nov-08 N558SR Cirrus Design Corporation SR22 Glass cockpit NonFatal

CEN09FA083 6-Dec-08 N6053B Cessna Aircraft Company 206 Glass cockpit Fatal

CEN09WA033 22-Oct-08 N467BD Cirrus Design Corporation SR22 Glass cockpit Fatal

CHI02FA231 4-Aug-02 N316PM Piper Aircraft, Inc. PA-46-350 Conventional Fatal

CHI02LA258 17-Aug-02 N336CB Hawker Beechcraft 36 Conventional NonFatal

CHI03FA057 18-Jan-03 N9523P Cirrus Design Corporation SR22 Conventional Fatal

CHI03FA284A 22-Aug-03 N53033 Cessna Aircraft Company 172 Conventional Fatal

CHI03LA061 31-Jan-03 N670CS Cessna Aircraft Company 172 Conventional NonFatal

CHI04CA251 9-Sep-04 N379BF Cessna Aircraft Company 182 Glass cockpit NonFatal

CHI04FA257 12-Sep-04 N843MC Cessna Aircraft Company 182 Conventional Fatal

CHI05CA007 16-Oct-04 N555MN Cirrus Design Corporation SR22 Glass cockpit NonFatal

CHI05CA027 31-Oct-04 N814FA Cessna Aircraft Company 182 Conventional NonFatal

CHI05CA035 21-Nov-04 N967SA Cessna Aircraft Company 172 Conventional NonFatal

CHI05CA085 2-Apr-05 N8150F Cirrus Design Corporation SR22 Glass cockpit NonFatal
NTSB Aviation Safety Study

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ntsb_no ev_date Registration Make Model Glass Severity

CHI05FA042 9-Dec-04 N587C Piper Aircraft, Inc. PA-32-301 Conventional Fatal

CHI05LA223 10-Aug-05 N795WW Cirrus Design Corporation SR20 Glass cockpit NonFatal

CHI05LA227 11-Aug-05 N632FA Cessna Aircraft Company 172 Conventional NonFatal

CHI06CA122 28-Apr-06 N1129P Cessna Aircraft Company 182 Glass cockpit NonFatal

CHI06CA133 20-May-06 N814SN Cirrus Design Corporation SR22 Conventional NonFatal

CHI06CA135 23-May-06 N409TA Cessna Aircraft Company 172 Conventional NonFatal

CHI06CA183 8-Jul-06 N335SP Cessna Aircraft Company 172 Conventional NonFatal

CHI06CA189 13-Jul-06 N918TA Cessna Aircraft Company 172 Conventional NonFatal

CHI06CA197 22-Jul-06 N52728 Cessna Aircraft Company 206 Conventional NonFatal

CHI06CA267 15-Sep-06 N6500V Lancair/Columbia Aircraft/Cessna Aircraft Company 350 Glass cockpit NonFatal

CHI06CA276 6-Sep-06 N2430A Cessna Aircraft Company 206 Glass cockpit NonFatal

CHI06FA043 11-Dec-05 N621PH Cirrus Design Corporation SR22 Glass cockpit Fatal

CHI06FA186 11-Jul-06 N8163Q Cirrus Design Corporation SR22 Glass cockpit Fatal

CHI06FA218 5-Aug-06 N658CD Cirrus Design Corporation SR22 Glass cockpit NonFatal

CHI06FA245 28-Aug-06 N91MB Cirrus Design Corporation SR22 Glass cockpit Fatal

CHI07CA308 29-Sep-07 N2327J Cessna Aircraft Company 172 Glass cockpit NonFatal

CHI07LA164 7-May-07 N51827 Cessna Aircraft Company 172 Conventional NonFatal

CHI08CA002 3-Oct-07 N437ND Piper Aircraft, Inc. PA-28-161 Conventional NonFatal

CHI08CA029 29-Oct-07 N77LU Cessna Aircraft Company 172 Conventional NonFatal

CHI08CA091 17-Mar-08 N53417 Cessna Aircraft Company 172 Conventional NonFatal

CHI08CA138 21-May-08 N1387C Lancair/Columbia Aircraft/Cessna Aircraft Company 400 Glass cockpit NonFatal

CHI08CA263 25-Aug-08 N1281 Cirrus Design Corporation SR20 Glass cockpit NonFatal

DCA07MA003 11-Oct-06 N929CD Cirrus Design Corporation SR20 Conventional Fatal

DCA07WA024 2-Feb-07 N901SR Cirrus Design Corporation SR20 Glass cockpit Fatal

DEN03LA017 20-Nov-02 N850FS Piper Aircraft, Inc. PA-28-201 Conventional NonFatal

DEN04CA137 29-Aug-04 N2099J Cessna Aircraft Company 172 Conventional NonFatal

DEN04FA087 7-Jun-04 N6162E Hawker Beechcraft 36 Conventional Fatal

DEN04LA053A 26-Mar-04 N5345G Cessna Aircraft Company 172 Conventional NonFatal

DEN05LA022 29-Oct-04 N203RF Cirrus Design Corporation SR22 Glass cockpit NonFatal

DEN06CA022 10-Dec-05 N1053X Cessna Aircraft Company 172 Conventional NonFatal

DEN06FA023 13-Dec-05 N1257Z Cessna Aircraft Company 172 Conventional Fatal

DEN06FA114 15-Aug-06 N8127J Cirrus Design Corporation SR20 Glass cockpit NonFatal

DEN06FA131 15-Sep-06 N787SL Cirrus Design Corporation SR20 Glass cockpit Fatal

DEN07CA128 26-Jul-07 N1049V Cessna Aircraft Company 182 Glass cockpit NonFatal

DEN07CA154 13-Aug-07 N249FS Cessna Aircraft Company 172 Glass cockpit NonFatal

DEN07LA082 9-Apr-07 N953CD Cirrus Design Corporation SR22 Glass cockpit NonFatal

DEN07LA119 11-Jul-07 N97PP Cessna Aircraft Company 206 Glass cockpit NonFatal

DEN07LA137 14-Aug-07 N395MR Mooney M20 Glass cockpit NonFatal

DEN07WA005 8-Oct-06 N147SR Cirrus Design Corporation SR22 Glass cockpit NonFatal

DEN08CA051 17-Jan-08 N819C Piper Aircraft, Inc. PA-32-301 Glass cockpit NonFatal

DEN08FA141 15-Aug-08 N487TC Cessna Aircraft Company 182 Glass cockpit Fatal

DEN08LA111 21-Jun-08 N5178Y Cessna Aircraft Company 172 Conventional NonFatal

DFW05CA077 21-Jan-05 N832TC Cessna Aircraft Company 182 Conventional NonFatal

DFW05CA253 29-Sep-05 N5343U Cessna Aircraft Company 172 Conventional NonFatal

DFW06CA098 9-Apr-06 N358TW Cessna Aircraft Company 172 Conventional NonFatal

DFW06LA038 9-Dec-05 N302BY Cirrus Design Corporation SR22 Glass cockpit NonFatal

DFW06LA101 7-Apr-06 N142SF Cirrus Design Corporation SR20 Glass cockpit NonFatal

DFW07CA012 15-Oct-06 N1013Y Cessna Aircraft Company 182 Glass cockpit NonFatal
NTSB Aviation Safety Study

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ntsb_no ev_date Registration Make Model Glass Severity

DFW07CA210 28-Sep-07 N364GW Cessna Aircraft Company 172 Conventional NonFatal

DFW07FA019 5-Nov-06 N53443 Cessna Aircraft Company 172 Conventional Fatal

DFW07LA021 31-Oct-06 N506C Piper Aircraft, Inc. PA-32-301 Glass cockpit NonFatal

DFW07LA207 25-Sep-07 N22237 Cessna Aircraft Company 172 Glass cockpit NonFatal

DFW08CA021 26-Oct-07 N5181A Cessna Aircraft Company 172 Conventional NonFatal

DFW08FA060 2-Feb-08 N824BJ Cirrus Design Corporation SR22 Glass cockpit Fatal

DFW08FA111 22-Apr-08 N729SR Cirrus Design Corporation SR22 Glass cockpit Fatal

DFW08FA204 10-Aug-08 N214MT Cessna Aircraft Company 182 Conventional Fatal

ERA09CA007 7-Oct-08 N889LD Cirrus Design Corporation SR20 Glass cockpit NonFatal

ERA09CA016 6-Oct-08 N22AS Cessna Aircraft Company 182 Glass cockpit NonFatal

ERA09CA017 7-Oct-08 N771CP Cessna Aircraft Company 182 Glass cockpit NonFatal

ERA09CA035 1-Nov-08 N2055R Cessna Aircraft Company 172 Conventional NonFatal

ERA09CA041 6-Nov-08 N1242C Cessna Aircraft Company 172 Glass cockpit NonFatal

ERA09CA110 27-Dec-08 N178AF Cessna Aircraft Company 172 Conventional NonFatal

ERA09FA053 13-Nov-08 N827GM Cirrus Design Corporation SR22 Conventional Fatal

FTW02CA249 4-Sep-02 N9855S Piper Aircraft, Inc. PA-28-161 Conventional NonFatal

FTW04CA163 16-Jun-04 N2101M Cessna Aircraft Company 172 Conventional NonFatal

FTW04LA072 7-Feb-04 N2124Z Cessna Aircraft Company 172 Conventional NonFatal

FTW04LA123A 9-May-04 N89SE Diamond Aircraft DA40 Conventional NonFatal

FTW04LA178 24-Jun-04 N810SA Cessna Aircraft Company 172 Conventional NonFatal

IAD03FA039 20-Mar-03 N1005P Mooney M20 Conventional Fatal

IAD04CA009 5-Feb-04 N5165M Cessna Aircraft Company 172 Conventional NonFatal

IAD05CA014 19-Nov-04 N2120M Cessna Aircraft Company 172 Conventional NonFatal

IAD05CA056 16-Apr-05 N127X Diamond Aircraft DA40 Glass cockpit NonFatal

IAD05CA131 5-Sep-05 N209SL Cirrus Design Corporation SR22 Glass cockpit NonFatal

IAD05FA032 15-Jan-05 N889JB Cirrus Design Corporation SR22 Glass cockpit Fatal

IAD05LA043B 9-Mar-05 N3513F Cessna Aircraft Company 172 Conventional NonFatal

IAD05LA111 20-Jul-05 N1328N Cessna Aircraft Company 182 Glass cockpit NonFatal

LAX02LA192 8-Jun-02 N480DW Cessna Aircraft Company 172 Conventional NonFatal

LAX03LA170 29-May-03 N5329L Cessna Aircraft Company 172 Conventional NonFatal

LAX03LA186 8-Jun-03 N519ER Cessna Aircraft Company 172 Conventional NonFatal

LAX03LA228 7-Jul-03 N288PA Piper Aircraft, Inc. PA-28-181 Conventional NonFatal

LAX03LA231 12-Jul-03 N5327G Cessna Aircraft Company 172 Conventional NonFatal

LAX03LA273 31-Aug-03 N280KT Piper Aircraft, Inc. PA-46-350 Conventional NonFatal

LAX04CA130 14-Feb-04 N262TA Cessna Aircraft Company 172 Conventional NonFatal

LAX04CA288 8-Aug-04 N5327G Cessna Aircraft Company 172 Conventional NonFatal

LAX04LA060 6-Dec-03 N396TA Cessna Aircraft Company 172 Conventional NonFatal

LAX04LA211 14-May-04 N5341G Cessna Aircraft Company 182 Conventional NonFatal

LAX04LA324 19-Sep-04 N931CD Cirrus Design Corporation SR22 Conventional NonFatal

LAX05CA028 5-Nov-04 N20519 Cessna Aircraft Company 172 Conventional NonFatal

LAX05CA299 4-Sep-05 N53056 Cessna Aircraft Company 172 Conventional NonFatal

LAX05FA032 10-Nov-04 N803ZG Piper Aircraft, Inc. PA-32-301 Glass cockpit Fatal

LAX05FA088 6-Feb-05 N286CD Cirrus Design Corporation SR22 Glass cockpit Fatal

LAX05LA073 18-Jan-05 N2157H Cessna Aircraft Company 172 Conventional Fatal

LAX05LA109 7-Mar-05 N517SW Cirrus Design Corporation SR22 Glass cockpit NonFatal

LAX05LA118 22-Mar-05 N562AB Cessna Aircraft Company 172 Conventional NonFatal

LAX05LA210 18-Jun-05 N626Z Cirrus Design Corporation SR22 Glass cockpit NonFatal

LAX06CA039 30-Oct-05 N51732 Cessna Aircraft Company 182 Conventional NonFatal
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ntsb_no ev_date Registration Make Model Glass Severity

LAX06CA128 9-Mar-06 N8141L Cirrus Design Corporation SR22 Glass cockpit NonFatal

LAX06CA173 28-Apr-06 N1488C Cirrus Design Corporation SR20 Conventional NonFatal

LAX06CA218 27-Jun-06 N562H Cessna Aircraft Company 206 Glass cockpit NonFatal

LAX06FA014 17-Oct-05 N285JB Lancair/Columbia Aircraft/Cessna Aircraft Company 400 Glass cockpit Fatal

LAX06FA087 9-Jan-06 N526CD Cirrus Design Corporation SR20 Glass cockpit Fatal

LAX06FA186 27-May-06 N451JE Cessna Aircraft Company 182 Glass cockpit Fatal

LAX06FA243 23-Jul-06 N241JL Hawker Beechcraft 36 Glass cockpit Fatal

LAX07CA092 14-Feb-07 N289SP Cessna Aircraft Company 172 Conventional NonFatal

LAX07CA101 3-Mar-07 N526ER Cessna Aircraft Company 172 Conventional NonFatal

LAX07CA139 28-Apr-07 N1273E Cessna Aircraft Company 206 Glass cockpit NonFatal

LAX07CA171 7-May-07 N533ER Cessna Aircraft Company 172 Conventional NonFatal

LAX07CA185 2-Jun-07 N65755 Cessna Aircraft Company 172 Conventional NonFatal

LAX07CA193 24-Jun-07 N567DD Cessna Aircraft Company 172 Glass cockpit NonFatal

LAX07CA199 1-Jul-07 N214GZ Cessna Aircraft Company 172 Glass cockpit NonFatal

LAX07CA202 3-Jul-07 N619TH Cessna Aircraft Company 172 Glass cockpit NonFatal

LAX07CA213 9-Jul-07 N747PZ Diamond Aircraft DA40 Glass cockpit NonFatal

LAX07FA021 25-Oct-06 N121LD Cirrus Design Corporation SR22 Glass cockpit Fatal

LAX07FA062 18-Dec-06 N457S Cirrus Design Corporation SR22 Glass cockpit Fatal

LAX07FA160 11-May-07 N512DS Diamond Aircraft DA40 Glass cockpit Fatal

LAX08CA084 22-Mar-08 N3105Q Piper Aircraft, Inc. PA-32-301 Glass cockpit NonFatal

LAX08CA102 13-Apr-08 N21705 Cessna Aircraft Company 172 Conventional NonFatal

LAX08CA124 7-Apr-08 N65630 Cessna Aircraft Company 172 Conventional NonFatal

LAX08CA158 28-May-08 N2252Z Cessna Aircraft Company 182 Glass cockpit NonFatal

LAX08CA189 24-Jun-08 N877CM Cirrus Design Corporation SR22 Glass cockpit NonFatal

LAX08FA023 28-Oct-07 N21101 Cessna Aircraft Company 172 Conventional Fatal

LAX08FA261 7-Aug-08 N15963 Cessna Aircraft Company 172 Glass cockpit Fatal

LAX08FA265B 10-Aug-08 N8341 Cirrus Design Corporation SR22 Glass cockpit Fatal

LAX08LA179 12-Jun-08 N233GW Cessna Aircraft Company 172 Conventional NonFatal

LAX08LA191 22-Jun-08 N2436F Cessna Aircraft Company 172 Glass cockpit Fatal

LAX08LA217 6-Jul-08 N2544W Lancair/Columbia Aircraft/Cessna Aircraft Company 400 Glass cockpit NonFatal

LAX08LA283 30-Jul-08 N5329L Cessna Aircraft Company 172 Conventional NonFatal

MIA03CA125 18-Jun-03 N53352 Cessna Aircraft Company 172 Conventional NonFatal

MIA03LA096 12-Apr-03 N52903 Cessna Aircraft Company 172 Conventional NonFatal

MIA03LA144B 18-Jul-03 N431ER Cessna Aircraft Company 172 Conventional NonFatal

MIA04CA028 21-Nov-03 N378FA Cessna Aircraft Company 172 Conventional NonFatal

MIA04CA077 17-Apr-04 N5280D Cessna Aircraft Company 172 Conventional NonFatal

MIA04CA106 17-Jul-04 N315PA Piper Aircraft, Inc. PA-28-181 Conventional NonFatal

MIA04CA109 12-Aug-04 N21063 Cessna Aircraft Company 172 Conventional NonFatal

MIA04FA045 19-Jan-04 N298PA Piper Aircraft, Inc. PA-28-181 Conventional Fatal

MIA05CA121 2-May-05 N66113 Cessna Aircraft Company 172 Conventional NonFatal

MIA05CA156 13-Sep-05 N513JG Cessna Aircraft Company 172 Conventional NonFatal

MIA05FA140 30-Jul-05 N65982 Cessna Aircraft Company 172 Conventional Fatal

MIA05LA042A 6-Dec-04 N294PA Piper Aircraft, Inc. PA-28-181 Conventional NonFatal

MIA05LA043 17-Dec-04 N375LP Cessna Aircraft Company 172 Conventional NonFatal

MIA05LA083 28-Mar-05 N53589 Cessna Aircraft Company 172 Conventional NonFatal

MIA05LA129 2-Jul-05 N53269 Cessna Aircraft Company 172 Conventional NonFatal

MIA05LA143 4-Aug-05 N513CD Cirrus Design Corporation SR22 Glass cockpit NonFatal

MIA06CA021 18-Nov-05 N5182Z Cessna Aircraft Company 172 Conventional NonFatal
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ntsb_no ev_date Registration Make Model Glass Severity

MIA06CA072 26-Mar-06 N326XT Piper Aircraft, Inc. PA-32-301 Conventional NonFatal

MIA06CA079 5-Apr-06 N4654M Mooney M20 Glass cockpit NonFatal

MIA06FA050 4-Feb-06 N667WP Cirrus Design Corporation SR22 Conventional Fatal

MIA06LA067 18-Mar-06 N777YM Cirrus Design Corporation SR20 Glass cockpit NonFatal

MIA07CA008 21-Oct-06 N401ER Cessna Aircraft Company 172 Glass cockpit NonFatal

MIA07CA019 19-Nov-06 N53095 Cessna Aircraft Company 172 Conventional NonFatal

MIA07CA045 27-Jan-07 N20956 Cessna Aircraft Company 172 Conventional NonFatal

MIA07CA101 24-May-07 N904MM Mooney M20 Glass cockpit NonFatal

MIA07CA115 1-Jul-07 N321MD Mooney M20 Glass cockpit NonFatal

MIA08CA056 15-Feb-08 N618VT Cessna Aircraft Company 172 Conventional NonFatal

MIA08CA068 26-Jan-08 N65329 Cessna Aircraft Company 172 Conventional NonFatal

MIA08CA073 6-Mar-08 N213LP Cessna Aircraft Company 182 Glass cockpit NonFatal

MIA08CA092 20-Apr-08 N375LP Cessna Aircraft Company 172 Conventional NonFatal

MIA08CA112 5-Jun-08 N300PB Cirrus Design Corporation SR22 Glass cockpit NonFatal

MIA08CA124 20-Jun-08 N65357 Cessna Aircraft Company 172 Conventional NonFatal

MIA08CA165 9-Aug-08 N1600U Cessna Aircraft Company 172 Conventional NonFatal

MIA08CA192 11-Sep-08 N710ND Hawker Beechcraft 36 Glass cockpit NonFatal

MIA08FA081 20-Mar-08 N615WM Cirrus Design Corporation SR22 Glass cockpit Fatal

MIA08FA115 7-Jun-08 N206GG Cessna Aircraft Company 206 Glass cockpit Fatal

MIA08LA132 14-Jun-08 N166DS Lancair/Columbia Aircraft/Cessna Aircraft Company 350 Glass cockpit NonFatal

NYC02FA089 24-Apr-02 N837CD Cirrus Design Corporation SR22 Conventional Fatal

NYC04CA085 10-Mar-04 N316MA Diamond Aircraft DA40 Conventional NonFatal

NYC04CA094 25-Mar-04 N340PA Piper Aircraft, Inc. PA-28-181 Conventional NonFatal

NYC04CA164 30-Jun-04 N421RW Cessna Aircraft Company 172 Conventional NonFatal

NYC04LA061 22-Jan-04 N344CD Cirrus Design Corporation SR22 Conventional NonFatal

NYC04LA209 11-Sep-04 N579AL Cirrus Design Corporation SR22 Glass cockpit NonFatal

NYC05LA024 21-Nov-04 N5294W Cessna Aircraft Company 172 Conventional NonFatal

NYC05LA040 22-Dec-04 N714KL Piper Aircraft, Inc. PA-46-350 Conventional NonFatal

NYC05LA110 30-Jun-05 N3452L Cirrus Design Corporation SR22 Glass cockpit NonFatal

NYC05LA131 7-Aug-05 N915DJ Cirrus Design Corporation SR20 Conventional NonFatal

NYC06CA058 22-Jan-06 N285MG Cirrus Design Corporation SR22 Glass cockpit NonFatal

NYC06CA116 14-May-06 N642KM Cessna Aircraft Company 172 Glass cockpit NonFatal

NYC06CA232 30-Sep-06 N61WT Cessna Aircraft Company 172 Glass cockpit NonFatal

NYC06FA072 22-Feb-06 N400WX Lancair/Columbia Aircraft/Cessna Aircraft Company 400 Glass cockpit Fatal

NYC06WA203 12-Aug-06 N357MV Cirrus Design Corporation SR22 Conventional NonFatal

NYC07CA010 19-Oct-06 N246MT Cirrus Design Corporation SR22 Glass cockpit NonFatal

NYC07CA074 9-Mar-07 N323RW Mooney M20 Conventional NonFatal

NYC07CA112 4-May-07 N462ER Cessna Aircraft Company 172 Glass cockpit NonFatal

NYC07CA116 9-May-07 N924LP Cessna Aircraft Company 172 Conventional NonFatal

NYC07CA131 2-Jun-07 N2298W Cessna Aircraft Company 172 Glass cockpit NonFatal

NYC07FA037 30-Nov-06 N665CD Cirrus Design Corporation SR22 Glass cockpit Fatal

NYC07FA083 24-Mar-07 N324ST Piper Aircraft, Inc. PA-32-301 Glass cockpit Fatal

NYC07FA126 26-May-07 N2537A Lancair/Columbia Aircraft/Cessna Aircraft Company 350 Glass cockpit Fatal

NYC07LA032 17-Nov-06 N1442E Lancair/Columbia Aircraft/Cessna Aircraft Company 400 Glass cockpit NonFatal

NYC07LA134 8-Jun-07 N729P Hawker Beechcraft 36 Conventional NonFatal

NYC08CA179 10-May-08 N65433 Cessna Aircraft Company 182 Glass cockpit NonFatal

NYC08CA187 7-May-08 N513JG Cessna Aircraft Company 172 Conventional NonFatal

NYC08CA214 13-Jun-08 N65939 Cessna Aircraft Company 172 Conventional NonFatal
NTSB Aviation Safety Study

79

ntsb_no ev_date Registration Make Model Glass Severity

NYC08CA233 29-Jun-08 N357TG Cessna Aircraft Company 182 Glass cockpit NonFatal

NYC08CA282 10-Aug-08 N5210A Cessna Aircraft Company 172 Conventional NonFatal

NYC08FA041 21-Nov-07 N108GD Cirrus Design Corporation SR20 Conventional Fatal

NYC08FA138 14-Mar-08 N141SR Cirrus Design Corporation SR22 Glass cockpit Fatal

NYC08LA004 5-Oct-07 N5205X Cirrus Design Corporation SR22 Conventional NonFatal

SEA04LA040 10-Feb-04 N6503C Lancair/Columbia Aircraft/Cessna Aircraft Company 350 Glass cockpit NonFatal

SEA05FA023 4-Dec-04 N1159C Cirrus Design Corporation SR22 Glass cockpit Fatal

SEA05FA038 20-Jan-05 N6057M Cirrus Design Corporation SR22 Glass cockpit Fatal

SEA05FA075 12-Apr-05 N448T Hawker Beechcraft 36 Conventional Fatal

SEA06CA187 22-Sep-06 N320CP Cessna Aircraft Company 172 Conventional NonFatal

SEA06TA118 30-May-06 N8210G Cessna Aircraft Company 206 Conventional NonFatal

SEA07CA003 5-Oct-06 N134GW Cessna Aircraft Company 182 Conventional NonFatal

SEA07CA064 24-Feb-07 N224MT Cirrus Design Corporation SR22 Glass cockpit NonFatal

SEA07CA089 31-Mar-07 N65067 Cessna Aircraft Company 206 Glass cockpit NonFatal

SEA07CA207 18-Jul-07 N907JW Cessna Aircraft Company 172 Conventional NonFatal

SEA07FA247 31-Aug-07 N2520P Lancair/Columbia Aircraft/Cessna Aircraft Company 400 Glass cockpit Fatal

SEA07LA013 31-Oct-06 N2097G Cessna Aircraft Company 172 Conventional NonFatal

SEA08CA052 26-Dec-07 N13974 Cessna Aircraft Company 172 Glass cockpit NonFatal

SEA08CA131 10-May-08 N196DC Diamond Aircraft DA40 Glass cockpit NonFatal

SEA08CA205 19-Sep-08 N420FP Diamond Aircraft DA40 Glass cockpit NonFatal

SEA08FA023 8-Nov-07 N881CP Cessna Aircraft Company 182 Glass cockpit Fatal

SEA08FA078 16-Feb-08 N621ER Lancair/Columbia Aircraft/Cessna Aircraft Company 400 Glass cockpit Fatal

SEA08FA108 8-Apr-08 N868PC Cirrus Design Corporation SR22 Glass cockpit Fatal

SEA08LA015A 30-Oct-07 N309PA Piper Aircraft, Inc. PA-28-181 Conventional NonFatal

SEA08LA095 25-Mar-08 N432RM Piper Aircraft, Inc. PA-28-181 Glass cockpit NonFatal

WPR09CA007 9-Oct-08 N206TT Cessna Aircraft Company 206 Glass cockpit NonFatal

WPR09CA066 21-Dec-08 N379P Piper Aircraft, Inc. PA-46-350 Glass cockpit NonFatal

WPR09CA273 5-Oct-08 N6048Z Cessna Aircraft Company 172 Glass cockpit NonFatal

WPR09LA049 27-Nov-08 N936EW Hawker Beechcraft 36 Glass cockpit NonFatal