Annual Review of Aircraft Accident Data

U.S. General Aviation, Calendar Year 1998

National 

Transportation 

Safety Board

Washington, D.C.

A

A

N TION

L TRA SPOR

ATIO

N

B OARD

SAF E T Y

N

T

E PLURIBUS UNUM 

NTSB/ARG-03/01

PB2003-104874

National Transportation Safety Board

490 L’Enfant Plaza, S.W.

Washington, D.C. 20594

Annual Review of Aircraft Accident Data

U.S. General Aviation, Calendar Year 1998

NTSB/ARG-03/01

PB2003-104874

Notation 7534

Adopted March 20, 2003
National Transportation Safety Board. 2003. ransportation Safety Board. 2003. U.S. General Aviation, Calendar Year 1998. Annual Review of eview of

Aircraft Accident Data NTSB/ARG-03/01 Washington, D.C.

Abstract: A total of 1,928 aircraft were involved in 1,904 accidents during calendar year 1998. The total number of general

aviation accidents occurring in 1998 represented a 3.2% increase over calendar year 1997. Of the total number of accidents, 364

were fatal accidents that resulted in a total of 624 fatalities. Although the number of fatal general aviation accidents in 1998

represented a 4% increase over calendar year 1997, the number of resulting fatalities declined 1.1% between 1997 and 1998. The

circumstances of these accidents and the details related to the aircraft, pilots, and locations involved are represented throughout this

report.

The National Transportation Safety Board 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 Safety Board 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 Web at <http://www.ntsb.gov>. Other information about available publications also may be

obtained from the Web site or by contacting:

National Transportation Safety Board

Public Inquiries Section, RE-51

490 L’Enfant Plaza, S.W.

Washington, D.C. 20594

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

Safety Board publications may be purchased, by individual copy or by subscription, from the National Technical Information Service. To purchase this

publication, order report number PB2003-104874 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 Board reports related to an

incident or accident in a civil action for damages resulting from a matter mentioned in the report.
INTRODUCTION ........................................................1

Purpose of the Annual Review..............................................1

What Is General Aviation?................................................1

Which Operations Are Included in this Review?..................1

Which Aircraft Are Included in this Review?....................1

Changes to the Annual Review............................................2

1998 GENERAL AVIATION ACCIDENT SUMMARY................3

OVERVIEW OF THE STATE OF THE GENERAL AVIATION

ENVIRONMENT IN 1998.............................................4

General Economic and Aviation Industry Indicators ...........4

Fleet Makeup..................................................................5

General Aviation Activity...................................................6

HISTORICAL AND CURRENT ACCIDENT DATA......................9

Typical General Aviation Accident Characteristics..............12

Time of Accident.............................................................13

Location.......................................................................14

1998 IN DEPTH .....................................................15

Location of General Aviation Accidents in 1998................15

United States Aircraft Accidents..............................15

Foreign Aircraft Accidents.....................................16

Aircraft Type.........................................................16

Type of Flying........................................................17

Flight Plan............................................................18

Airport Involvement...............................................18

Injuries and Damage for 1998........................................18

Aircraft Damage...................................................18

Accident Injuries...................................................19

Injuries by Role for 1998................................................20

Accident-involved Pilots....................................................21

Rating..................................................................21

Total Time............................................................22

Time in Type of Aircraft..........................................24

Age...............................................................................25

Medical Certification............................................26

Accident Occurrences for 1998........................................28

Phase of Flight................................................................30

Most Prevalent Causes/Factors for 1998..........................31

Probable Causes, Factors, and the Broad

Cause/Factor Classification..................................31

Human Performance.............................................33

GENERAL AVIATION SAFETY ISSUES................................34

Survivability.......................................................................34

Midair Collisions................................................................36

Collisions with Terrain or Objects........................................37

Weather as a Cause/Factor.................................................38

SPECIAL TOPIC.........................................................40

Accidents in Instrument Meteorological Conditions...........40

APPENDIXES

A: Definitions...................................................................45

B: The National Transportation Safety Board

Investigative Process...........................................................46

C: The National Transportation Safety Board

Aviation Accident/Incident Database...............................47

D: National Transportation Safety Board

Regional Offices..............................................................48

CONTENTS

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INTRODUCTION

Purpose of the Annual Review

The National Transportation Safety Board’s 1998 Annual Review

of Aircraft Accident Data for U.S. General Aviation presents a

statistical compilation and review of general aviation accidents

that occurred in 1998 involving U.S.-registered aircraft. In

addition to providing accident statistics for 1998, the review also

includes general economic indicators that may have influenced

general aviation activity for 1998 and contextual accident data

from several years preceding the reporting period.

The accident data used in this review were extracted from the

Safety Board’s Aviation Accident/Incident Database.1 The activity

data used in this review were extracted from the General Aviation

and Air Taxi Activity Survey (GAATA Survey)

2 and from U.S. Civil

Airmen Statistics, both of which are published by the Federal

Aviation Administration (FAA), Statistics and Forecast Branch,

Planning and Analysis Division, Office of Aviation Policy and Plans.

Additional information was extracted from the General Aviation

Manufacturers Association (GAMA), General Aviation Statistical

Databook.

What Is General Aviation?

General Aviation can be described as any civil aircraft operation

that is not covered under 14 Code of Federal Regulations (CFR)

Parts 121, 129, and 135, commonly referred to as commercial

air carrier operations.3

Which Operations Are Included in this Review?

This review includes accidents involving U.S.-registered aircraft

operating under 14 CFR Part 91, as well as civilian public use4

aircraft operations. Aircraft operating under Part 91 include

aircraft that are flown for recreation and personal transportation,

as well as certain aircraft operations that are flown with the

intention of generating revenue,5 including business flying, flight

instruction, corporate/executive flights, positioning or ferry flights,

pipeline/powerline patrols, and news and traffic reporting.

Which Aircraft Are Included in this Review?

General aviation operations are conducted in a wide range of

aircraft, including airplanes, rotorcraft, gliders, balloons and

blimps, and registered ultralight, experimental, or amateur-built

aircraft.

1 A detailed description of the Aviation Accident/Incident Database is included in Appendix C.

2

 Data are available at <http://api.hq.faa.gov/pubsarchive.asp>. Although included in the GAATA Survey, data associated with air taxi and air tour operations are not

included in this review.

3

 For an analysis of accidents related to air carrier operations, see National Transportation Safety Board, Annual Review of Aircraft Accident Data, U.S. Air Carrier Operations,

Calendar Year 1998, NTSB/ARC-02-02 (Washington, DC: NTSB, 2002), available at <http://www.ntsb.gov>.

4

 Although the precise statutory definition has changed over the years, public aircraft operations are qualified government missions that may include law enforcement, lowlevel observation, aerial application, firefighting, search and rescue, biological or geological resource management, and aeronautical research.

5

 See 14 CFR 119.1.

1
The wide range of operations and aircraft types included within

the scope of general aviation must be considered when

interpreting the data presented in this review. For example, the

1998 general aviation review includes accidents involving aircraft

ranging in size from 250-pound ultralights to 40,000-pound

business jets.

Not included in this review are any accident data associated with

aircraft operating under 14 CFR Parts 121, 129, or 135, such

as scheduled 121 air carrier operations, foreign air carrier

operations, scheduled 135 air carrier operations (commuters),

and nonscheduled 135 air carrier operations (air taxis).

Also not included are data involving military or non-U.S.-registered

aircraft, such as military aircraft accidents, unless the accident

also involves civil aircraft, foreign-registered aircraft, unregistered

ultralights, and commercial space launches. Crashes involving

illegal operations or stolen aircraft are included in the accident

total, but not in accident rates.

Changes to the Annual Review

The Annual Review has been modified from past years and is

now organized into five parts.

• The first part presents a summary of the general aviation

accident statistics for 1998 and an overview of economic

and industry markers related to general aviation activity

in 1998, as well as contextual statistics from previous years.

• The second part investigates trends over the past 10 years

in terms of such factors as types of flight, levels of aircraft

damage, and level of injury.

• The third part focuses on accidents that occurred during

the 1998 calendar year and their circumstances. Cause

and factor findings for accidents occurring in 1998 are

also listed.

• The fourth part focuses on several issues particularly

relevant to general aviation safety. The 1998 Annual

Review focuses on the issues of survivability, midair

collisions, and controlled flight into terrain.

• The fifth part, new this year, is a special topic that provides

in-depth coverage of an important general aviation safety

topic. For the 1998 Annual Review, the special topic is

flight in instrument meteorological conditions (IMC).

In addition to being reorganized, the 1998 Annual Review presents

statistical data more graphically than in previous years. Readers who

wish to view the data in a tabular format or who wish to manipulate

the data used in the report may access the data set online at

http://www.ntsb.gov. They may also contact the Safety Board’s

Public Inquiries Branch at 202-314-6551or at 800-877-6799.

Annual Review of Aircraft Accident Data 2
1998 GENERAL AVIATION

ACCIDENT SUMMARY

A total of 1,928 aircraft were involved in 1,9046 accidents during

calendar year 1998.7 The total number of general aviation

accidents occurring in 1998 represented a 3.2% increase over

calendar year 1997. Of the total number of accidents, 364

were fatal accidents that resulted in a total of 624 fatalities.

Although the number of fatal general aviation accidents in 1998

represented a 4% increase over calendar year 1997, the number

of resulting fatalities declined 1.1% between 1997 and 1998.

The circumstances of these accidents and the details related to

the aircraft, pilots, and locations involved are presented

throughout this report.

6 There were 4 accidents, 2 of which were fatal, during 1998 involving stolen or unauthorized aircraft operations. For the purposes of this report, those accidents and aircraft

are included in accident totals but not in accident rates.

7 In this report, a collision between 2 aircraft is counted as a single accident. The 15 midair collision accidents that occurred in 1998 involved 27 general aviation aircraft

and 3 non-GA aircraft. The 14 ground collision accidents involved 21 general aviation aircraft and 9 non-general aviation aircraft.

3
8 U.S. Census Bureau data, which are available at <http://eire.census.gov/poptest/archives/pre1980/popclockest.txt>.

9 Bureau of Economic Analysis, real gross domestic product using chained 1996 dollars, available at <http://www.bea.doc.gov/bea/dn/gdplev.xls>.

10 Bureau of Economic Analysis, chained 1996 dollars, available at <http://www.bea.gov/bea/dn/nipaweb/>.

11 General Aviation Manufacturers Association, General Aviation Statistical Databook, 2001.

OVERVIEW OF THE STATE OF THE

GENERAL AVIATION ENVIRONMENT IN 1998

General Economic and Aviation

Industry Indicators

This overview of economic and industry indicators provides a

contextual background for 1998 general aviation (GA) accident

data. The following table provides U.S. economic indicators and

measures of personal income since 1975. The table also includes

U.S. economic indicators pertaining to the general aviation

industry.

General Economic and Aviation Industry Indicators 1975-1998

 1975 1980 1985 1990 1995 1998

Population (Millions)8 216.0 227.2 237.9 249.5 262.8 270.2

Gross Domestic Product (Billions)9 $4,084.4 $4,900.9 $5,717.1 $6,707.9 $7,543.8 $8,508.9

Disposable Personal Income (Billions)10 $3,108.5 $3,658.0 $4,347.8 $5,014.2 $5,539.1 $6,168.6

Disposable Personal Income Per Capita8 $14,393 $16,063 $18,229 $20,058 $20,795 $22,354

Number of GA Aircraft Sold11 14,056 11,877 2,029 1,144 1,077 2,200

Net Factory Billings for GA Aircraft (Millions) 9 $1,032.9 $2,486.2 $1,430.6 $2,007.5 $2,841.9 $5,761.2

Value of New GA Aircraft Sold: Piston $570 $794 $194 $92 $123 $330

Value of New GA Aircraft Sold: Turbine (Millions) 9 $461 $1,691 $1,237 $1,916 $2,719 $5,431

4

The table shows steady growth in U.S. industrial and personal

income since 1975. The table also shows that, between 1995

and 1998, the U.S. resident population increased by 2.8%, the

gross domestic product rose by 12.8%, and disposable personal

income rose by 11.4%.

Between 1975 and 1995, economic indicators for the general

aviation industry were either generally steady or declining. The

number of aircraft sold in 1995 reflects a 92.3% decrease from

1975 sales. Net factory billings for new aircraft sold fluctuated

over the period, with 1995 billings 175% greater than those in

1975, primarily because an increase in the value of turbine aircraft

sales made up for losses in piston aircraft sales. In contrast to

the years between 1975 and 1995, which

had modest to negative growth, general

aviation industry indicators increased by

approximately 100% between 1995 and

1998. One reason for this rapid growth,

in addition to generally favorable economic

conditions, was the increased production

of general aviation aircraft following the

1994 passage of the General Aviation

Revitalization Act12 limiting manufacturer

liability.
5

Sharp declines in general aviation aircraft shipments13 during

the ’70s and ’80s were followed by gradual declines in the

numbers of shipments during the early ’90s and an increase in

shipments after 1994.

Fleet Makeup

Although sales of new general aviation aircraft have increased

over the last 5 years, most general aviation aircraft currently in

use are more than 20 years old. U.S. manufacturers delivered

2,200 new general aviation aircraft in 1998, compared to an

estimated total of 199,500 general aviation aircraft already in

Annual Shipments of New U.S. - Manufactured General Aviation

Aircraft 1980-1998 

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

1980 1982 1984 1986 1988 1990 1992 1994 1996 1998

Single-engine Multi-engine Turboprop Jet

12 The General Aviation Revitalization Act, signed into law August 17, 1994, limits the liability of general aviation manufacturers to 18 years.

13 General Aviation Statistical Databook, 2001.

service. Single-engine piston aircraft have the highest average

age of all types of general aviation aircraft and represent the

majority of the fleet. A consequence of this fleet makeup is that

changes incorporated into newly manufactured aircraft may not

be reflected in the accident record for several years.

Active Aircraft in General Aviation 1998 

Single-engine

piston

143,494 

Balloon

3,475 Homebuilt

13,189

Glider

2,105

Turboprop

5,215

Jet

5,551

Rotorcraft

6,268

Multi-engine

piston

16,870

Overview of the State of the General Aviation Environment in 1998
General Aviation Activity

Because of the diversity of aircraft types and operations included

in general aviation, activity level must be considered in order to

make meaningful comparisons of accident numbers among

aircraft types or types of operations. The level of activity

corresponds to the level of exposure to potential accident risk.

Total flight hours, departures, and miles flown are common

indicators used to measure activity.

Unlike Part 121 and scheduled Part 135 air carriers, which are

required to report total flight hours, departures, and miles flown

to the Department of Transportation (DOT) Research and Special

14 Part 121 operators report activity on a monthly basis, and scheduled Part 135 operators report quarterly.

15 Available at <http://api.hq.faa.gov/pubsarchive.asp>.

16 The 1998 GAATA Survey sample frame consisted of 255,309 registered aircraft, from which 30,114 records (11.8%) were selected in a sample stratified by state/territory

and aircraft type. Of that sample, 28,521 were found to include valid owner/address information. From the valid sample, 18,342 (64.3%) completed surveys were collected

(GAATA Survey, Calendar Year 1998).

Annual Review of Aircraft Accident Data 6

Programs Administration (RSPA),14 operators of general aviation

aircraft are not required to report actual flight activity data. As a

result, activity for this group of aircraft must be estimated using

data from the GAATA Survey.15 The GAATA Survey was

established in 1978 to gather information about aircraft use,

flight hours, and avionics equipment installations from owners of

general aviation and nonscheduled Part 135 aircraft. Because

activity totals are derived from a limited sample of aircraft16

selected from the registry of aircraft owners and reporting is not

required, activity data for general aviation are far less reliable

than the data available for air carriers.

Although included in the GAATA Survey, nonscheduled Part 135

operations are excluded from the 1998 Annual Review of General

Aviation Accidents. Accordingly, for this review, general aviation

activity was determined by subtracting those data pertaining to

nonscheduled Part 135 operations from activity totals whenever

possible. However, in many cases, general aviation activity data

could not be calculated because the survey data represent the

aggregate of all aircraft activity, including both general aviation

and nonscheduled Part 135 operations. Examples of such

aggregate data include the number of landings, flight hours by

state or region, and flight hours by day/night or weather

conditions.

Seats Average Age

Single-engine Piston 1-3 28

4 31

5-7 25

8+ 42

Multi-engine Piston 1-3 30

4 27

5-7 30

8+ 31

Turboprop all 19

Jet all 16

All Aircraft 27
Overview of the State of the General Aviation Environment in 1998 7

 	

 

  



  	 
   
  









	

	




The following graph illustrates the estimated total number of general

aviation flight hours annually for the years 1989 to 1998.17 General

aviation flight hours began to increase in 1994 after a decline during

the preceding years. The number of general aviation flight hours

in 1998 was estimated to be 25,518,000, a 14.8% increase

over the 10-year low of 22.2 million hours, estimated in 1994.

17 FAA, GAATA Survey, 1998, available at <http://api.hq.faa.gov/GAATA/GA98tables/table1-6.pdf>.

18 FAA, U.S. Civil Airmen Statistics, available at <http://api.hq.faa.gov/CivilAir/docs/air22-99.XLS>.

19 Based on medical certificates issued.

Two indirect indicators of general aviation activity are the number

of active pilots and the number of new pilot certificates issued.

The number of new student pilot certificates issued is particularly

meaningful because it represents positive growth in the pilot

New Student Pilot Certificates Issued 1990-1998

(1000s)

1990 1991 1992 1993 1994 1995 1996 1997 1998

20

40

60

80

100

0

population. The number of new student pilot certificates issued 18

decreased steadily each year from 88,586 in 1990 to 56,653 in

1996.19 Between 1996 and 1998, the number of new student

pilot certificates issued annually increased to a total of 63,037.
Annual Review of Aircraft Accident Data 8



















		 		 		 		
 		 		 				 		

 
 
 




Similarly, the total number of active pilots decreased throughout

the early and mid ’90s, decreasing steadily from 702,659 in

1990 to 622,261 in 1996. Between 1996 and 1998, the number

of active pilots began to level off to an estimated 618,298

U.S. pilots active in 1998.

In summary, the indicators of general aviation activity—flight hours

and the total number of active new and current pilot certificates

issued—decreased annually between 1990 and approximately

1996. Since then, these indicators have generally remained

steady or begun to increase. This noticeable change in activity

over the period should be considered when attempting to interpret

the general aviation accident record for 1998.
HISTORICAL AND CURRENT ACCIDENT DATA

The general aviation accident rate fluctuated between 1989 and

1998 with 7.45 accidents per 100,000 hours flown in 1998,

which was noticeably lower than the 1994 high of 9.09 accidents

per 100,000 hours. The fatal accident rate remained fairly

constant during the entire period, at 18 to 21% of the total

accident rate. Because rate calculations require the use of activity

data extrapolated from a relatively small sample of aircraft owners,

the resulting values are accurate only to the extent that the sample

represents the larger population of general aviation operators.

For this reason, accident rate data presented in this report will

include raw frequency data for comparison.

 	

 


 

  	
 
	













         



  
 

9

There was a stable, to slightly downward overall, trend in the

number of accidents that occurred annually between 1989 and

1997. The total number of general aviation accidents in 1998

(1,904) increased slightly (3.2%) from a 10-year low of 1,845

accidents in 1997. The number of fatal accidents increased to

364 (4%) in 1998 from the 10-year low of 350 in 1997.

 	 

   













      	 
 


  

624 in 1998. The observed decline in fatalities is consistent with

trends in both the level of activity and the number of fatal accidents

for those years.

 	

 

 

  	
 
	











         

 	 

 
    
 

















     	  
 



 
 


General aviation includes a wide range of operations, each with

unique aircraft types, flight profiles, and operating procedures.

This diversity is evident in the accident record.

Because the flight data collected in the GAATA Survey allows for

only a coarse representation of all general aviation operations,

the operations data presented here include only four operational

categories, which were selected as typical of general aviation

activity: personal/business flying,20 corporate flying, aerial

application, and instructional flights.

Annual Review of Aircraft Accident Data 10

The number of general aviation accidents occurring annually

has generally decreased over the last 10 years. However, general

aviation activity has also fluctuated over this period, and the

accident frequency appears to correspond to changes in new

aircraft sales, total general aviation flight hours, and new student

pilot starts.

In 1998, the fatality rate, or number of accident-related deaths

per flight hour, was 2.4 fatalities per 100,000 hours flown, the

lowest rate of the 10-year period between 1989 and 1998. The

high annual rate for this period occurred in 1992 with 3.5 deaths

per 100,000 hours flown.

The total number of fatalities resulting from general aviation

accidents between 1989 and 1998 reached a high of 867 in

1992 and then began a general downward trend to a low of

20 Because of the difficulty of accurately distinguishing between personal and business flying for both the activity survey and the accident record, the rate presented in this

report is calculated using combined exposure data (hours flown).
21 See 14 CFR Subpart H for flight instructor certificate and rating requirements.

Accident Rate by Type of Operation 1989-1998

per 100,000 hours flown

0

2

4

6

8

10

12

14

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Personal and Business Aerial Application Corporate Instructional

Historical and Current Accident Data 11

• Personal flying makes up the largest portion of general

aviation activity and includes all flying for pleasure and/

or personal transportation. Although similar to personal

flying, business flying includes the use of an aircraft for

business transportation without a paid, professional crew.

Personal and business flights are typically in single- and

multi-engine piston airplanes, but may include a range

of aircraft including gliders, rotorcraft, and balloons.

• Corporate flying includes any business transportation with

a professional crew and usually involves larger multiengine piston, turboprop, and jet airplanes.

• Aerial application includes the use of specially equipped

aircraft for seeding and for spraying pesticides, herbicides,

and fertilizer. Aerial application is unique because it

requires pilots to fly close to the ground.

• Instructional flying includes any flight under the supervision

of a certificated flight instructor.21 Aircraft used for

instructional flights are often similar to those used for

personal flying, but instructional operations are unique

because they often involve the repeated practice of takeoffs

and landings, flight maneuvers, and emergency

procedures.

Between 1989 and 1998, personal and business flying had the

highest accident rate, followed by aerial application and

instruction. The accident rate for corporate/executive

transportation was consistently the lowest overall, at only 3 to

10% of the next-lowest rate (that is, the rate that was observed

for instructional flying).

The vast majority of general aviation accidents involve personal

and business operations. Between 1989 and 1998, personal/

business flying accounted for an average 67% of all general

aviation accidents. Instructional flying has historically accounted

for the next highest number, with an average 14% of all general

aviation accidents.
The fatal accident rate is also highest for the combined category of

personal/business flying, which is typically more than double the

rate for any other type of flying. These differences are probably

related to the type of aircraft and equipment, the level of pilot training,

and the operating environments unique to each type of operation.

Number of Accidents by Type of Operation 1989-1998

0

200

400

600

800

1000

1200

1400

1600

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Personal and Business Aerial Application Corporate Instructional

Fatal Accident Rate by Type of Operation 1989-1998

per 100,000 hours flown

0

1

2

3

4

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Personal and Business Aerial Application Corporate Instructional

Typical General Aviation Accident Characteristics

The analysis of trends in accident data may be used to identify

potential safety-related issues. However, accident data trends

must be interpreted carefully to ensure that those results that

may indicate safety concerns are separated from those results

that simply reflect characteristics of normal operations. This is

especially true when interpreting general aviation accident data

that include a large percentage of recreational and pleasure

flying. In these cases, trends in the accident numbers may simply

be the result of exposure due to trends in general aviation activity.

Number of Fatal Accidents by Type of Operation 1989-1998

0

50

100

150

200

250

300

350

400

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Personal and Business Aerial Application Corporate Instructional

Annual Review of Aircraft Accident Data 12

Between 1989 and 1998, personal/business flying accounted

for an average 74.2% of fatal general aviation accidents and

75.3% of all fatal general aviation injuries. An average 548.5

fatal injuries per year between 1989 and 1998 were associated

with personal/business flying, compared to the average 48.1

deaths per year related to instructional flying.
Accidents by Month

0

50

100

150

200

250

300

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

1998

1988-1997

Average

Historical and Current Accident Data 13

A similar pattern emerges for the number of accidents that occur

each day of the week. The following graph depicts the number

of accidents per weekday for both 1998 and the average for the

preceding 10-year period. Again, the total number of accidents

in 1998 is lower than the 10-year average, but the daily

distribution of accidents for 1998 is similar to the historical

average. The number of accidents is relatively steady Monday

through Thursday, then begins to increase on Friday, and is highest

on Saturday and Sunday. Again, this distribution probably reflects

a weekend increase in recreational general aviation activity.

Depicted in the following graph are the numbers of accidents by

the time of day they occurred, with a comparison of 1998 accident

data with the average for the 10 years preceding 1998. As with

the previous data, the observed distribution should be considered

a result of exposure to risk due to the level of activity rather than a

risk associated with the time of day. For example, note the dip in

the number of accidents during the hours of noon and 1 p.m.,

probably corresponding to a reduction in activity during the lunch

hour.

The following section discusses what could be considered

“typical” characteristics of general aviation accidents. In most

cases, these characteristics reflect the fact that the bulk of pleasure

flying takes place on weekends during the summer months.

Time of Accident

The following graph depicts the number of accidents per month

over the last 10 years. The vertical bars depict 1998 accidents,

and the curved line represents the historical average. As the

graph illustrates, the total number of general aviation accidents

in 1998 was lower than the historical average, but the distribution

pattern remained similar. Data were not available for the number

of general aviation hours flown each month, but the consistent

pattern of increased accident numbers during the spring and

summer months, with a peak in July, probably results from

increased activity during these months rather than season-specific

hazards.

Accidents by Day of the Week

0

50

100

150

200

250

300

350

400

450

MO TU WE TH FR SA SU

1998

1988 -1997

average
Accidents by Hour of the Day (24-hour format)

0

50

100

150

200

0100 0200 0300 0400 0500 0600 0700 0800 0900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400

1998

1988-1997

Average

Top 15 General Aviation Accident States 1998

0 50 100 150 200 250 300

Pennsylvania

Indiana

Oklahoma

Wisconsin

New Mexico

Arkansas

Michigan

Georgia

Arizona

Colorado

Washington

Alaska

Texas

Florida

California

1998

1988-1997

Average

Annual Review of Aircraft Accident Data 14

Location

Just as seasonal and daily changes in the level of general aviation

activity can be observed in the number of general aviation accidents,

regional differences are also reflected in the accident record. Regional

differences that affect general aviation accident numbers include aviation

activity levels and hazards unique to the local terrain and/or weather.

The following graph shows the top 15 states by number of general

aviation accidents in 1998. Included for comparison are the average

numbers of accidents occurring in each of those states over the 10

years preceding 1998. As the graph illustrates, the distribution of

accidents among these 15 states is similar to that of their historical

averages. In order to make direct comparisons between the accident

risks associated with each state, the number of accidents should be

compared with a measure of general aviation activity level, such as the

number of hours flown in that state annually. Although the hourly activity

data needed to calculate general aviation accident rates for each state

were not available for 1998, some assumptions can be made about

general aviation activity level based on the size and population of each

state. For example, California, Florida, and Texas had the greatest

22 Data are available at <http://eire.census.gov/popest/archives/state/st-99-1.txt>.

number of accidents in 1998; U.S. Census Bureau data22 indicate

that California had the highest state population in 1998, followed

by Texas (second), and Florida (fourth). California, Florida, and

Texas are also popular travel destinations that would attract additional

general aviation traffic from other states. The next section includes

more detailed information about the locations of 1998 accidents,

and similar patterns can be observed in highly populated areas and

areas that are likely to attract visitors.
1998 IN DEPTH

Location of General Aviation Accidents in

1998

UNITED STATES AIRCRAFT ACCIDENTS

This map depicts the number of general aviation

accidents that occurred in each state during 1998. The

states are also color-coded from light to dark,

qualitatively signifying (from low to high) the number of

accidents. As discussed in the previous section, the

number of general aviation accidents occurring annually

in a state is related to the population, general aviation

activity level, and flying conditions unique to that state.

Although general aviation flight hours were not available

for each state, the largest numbers of general aviation

accidents during 1998 were in California, Texas, and

Florida,23 states that also had the largest numbers of active

pilots24 and active aircraft,25 suggesting that the number

of accidents may be related to activity. However, Alaska

23 The total of 151 accidents for Florida includes one accident off the coast of Florida in the Atlantic Ocean and one accident off the coast in the Gulf of Mexico.

24 FAA, U.S. Civil Airmen Statistics, 1998, available at <http://api.hq.faa.gov/airmen/98AirmenCnty.pdf>.

25 FAA, GAATA Survey, 1998, available at <http://api.hq.faa.gov/GAATA/GA98tables/table1-8.pdf>.

26 Because the GAATA Survey cannot accurately separate air taxi operations (unscheduled Part 135) from general aviation operations, the comparison between these

estimates is included only as a demonstration of similar activity.

27 For an analysis of aviation safety in Alaska, see National Transportation Safety Board, Aviation Safety in Alaska, Safety Study, NTSB/SS-95/03 (Washington, DC:

NTSB, 1995). The Safety Board is also supporting an ongoing effort to identify and mitigate risk factors specific to aviation operations in Alaska; for details, see

<http://www.ntsb.gov/aviation/AK/alaska_stat.htm>.

had the fourth-highest number of general aviation accidents with 128,

which was 2.7 times more than Michigan, a state estimated to have a

similar number of active aircraft and pilots.26 The operating environment,

infrastructure, and travel requirements in Alaska provide unique challenges 27

to aviation, and these challenges are reflected in the general aviation

accident record.

Accidents

44 to 207 (10)

32 to 44 (11)

25 to 32 (8)

16 to 25 (11)

 1 to 16 (10)

General Aviation Accidents per State 1998

151

49

49

44

129

57

53

128

60

207

2

20

23

3

1

15

22

8

16

24 24

28

31

30

9

7 6

35

36

29

9

32 33

42

35

20

27

26

41

21

26

13

21

42

31

19

35

38

37

23

15
FOREIGN AIRCRAFT ACCIDENTS

U.S.-registered aircraft were also involved in 33 accidents in

locations outside the 50 United States.28 These included15 different

countries, the Atlantic and Pacific Oceans, the Caribbean Sea,

and the Gulf of Mexico. Of those accidents, 17 were fatal,

resulting in 50 deaths and 10 serious injuries. The largest number

of accidents outside the 50 states occurred in the Bahamas, with

8 accidents, followed next by Canada with 4. Although most

general aviation accidents involving U.S.-registered aircraft

outside the United States usually occur in neighboring countries

like Canada and the Caribbean island nations, the 1998 accident

record also includes accidents that occurred as far away as

Ethiopia, Iceland, and the Philippines.

28 An additional four accidents (no injuries) occurred in the U.S. territory of Puerto Rico.

AIRCRAFT TYPE

The following graphs illustrate the total number of accidents and

the number of fatal accidents occurring in 1998 by type of aircraft.

Most notable is the large number of accidents involving singleengine piston aircraft, accounting for 73.8% of all general aviation

accidents and 69% of fatal accidents.

The general aviation accident rate for all aircraft was 7.44

accidents per 100,000 hours flown, and 1.41 fatal accidents

per 100,000 hours flown. Among fixed-wing powered aircraft,

the accident rate was highest for single-engine piston aircraft

with 8.49 accidents and 1.51 fatal accidents per 100,000 hours

flown. Among all powered aircraft, the accident rate was highest

for rotorcraft, with 12.18 accidents

and 2.13 fatal accidents per

100,000 hours flown. Glider

operations had the highest accident

rate, with 28.00 accidents and 3.20

fatal accidents per 100,000 hours

flown.

Annual Review of Aircraft Accident Data 16

Accidents Fatal Accidents Fatalities Serious Injuries

Off American Samoa (1)

Off Guam (1)

Missing off Azores (1)

Missing off Jamaica (1)

Operating from oil platforms (2)

Off Puerto Rico (1)

Missing off Bahamas (1)

Azores, Portugal (1)

Bahamas (8)

Belize (1)

Canada (4)

Colombia (1)

Ethiopia (1)

France (1)

Greenland (1)

Guatemala (1)

Haiti (1)

Iceland (1) 

Philippines (1)

Turks & Caicos Islands (1)

Isle of Man, UK (1)

Venezuela (1)

Total 33 17 50 10

Accidents Involving U.S. Registered General Aviation Aircraft Outside the 50 United States 1998 

25 10 37 10

2 25 0

2 11 0

Other Foreign

2 23 0

2 24 0

Pacific Ocean

Atlantic Ocean

Gulf of Mexico

Caribbean Sea
TYPE OF FLYING

Because, as mentioned previously, general aviation includes a

wide range of operations, each with unique aircraft types, flight

profiles, and operating procedures, the total number of accidents

and the accident rates vary considerably based on the type of

flying. The purpose of flight can be defined as the reason that

flight was initiated. Most general aviation operations are

conducted for personal and/or business purposes. Of the 25.5

million general aviation hours flown in 1998, more than half—13.3

million—were for personal or business reasons.29 Because of

this activity level, personal/business flying accounted for 67.7%

(1,286) of all general aviation accidents and 74.0% (268) of all

fatal general aviation accidents in 1998.

Although personal/business flying has historically had the highest

accident rate, aerial application had the highest accident rate in

1998 with 10.26 accidents per 100,000 hours. Because

accidents that occur during aerial application operations typically

involve contact with the ground, power lines, or other obstacles

at relatively low speeds and from relatively low altitudes, they

often do not result in fatal injury. Only 4.5% of the aerial

application accidents that occurred in 1998 resulted in fatalities,

compared to 20.8% of personal/business flying accidents.

When compared with the number of hours flown, the fatal

accident rate for aerial application operations is 0.46 fatal

accidents per 100,000 hours flown. The fatal accident rate

remains highest for personal and business flying, with 2.01 fatal

accidents per 100,000 hours flown.

29 FAA, GAATA Survey, 1998, available at <http://api.hq.faa.gov/GAATA/GA98tables/table1-6.pdf>.

1998 in Depth 17

Accident Rate by Aircraft Type 1998

per 100,000 hours flown

8.28

28.00

12.18

1.10

4.93

4.82

8.49

7.31

0.59

3.20

2.13

0.40

1.06

1.39

1.51

1.42

1.41

7.44

Balloons

Gliders

Rotorcraft

Airplane Turbojet

Airplane Turboprop

Airplane Multi-Engine Piston

Airplane Single Piston

All Powered Airplane

All Aircraft

Total

Fatal

Number of Accidents by Aircraft Type 1998

14

35

189

22

65

135

364

324

251

39

14

8

33

4

1

1,405

1,657

1,904

Balloons

Gliders

Rotorcraft

Airplane Turbojet

Airplane Turboprop

Airplane Multi-Engine Piston

Airplane Single Piston

All Powered Airplane

All Aircraft

Total

Fatal
 	
  

 
	 



	





	



	




	






	

Injuries and Damage for 1998

AIRCRAFT DAMAGE

Safety Board investigators record aircraft damage as either

“destroyed,” “substantial,” or “minor.” “Substantial damage” is

defined in 49 CFR 830.2 as “damage or failure which adversely

affects the structural strength, performance, or flight characteristics

of the aircraft, and which would normally require major repair or

replacement of the affected component.” “Destroyed” and

“minor” are not specifically defined in 49 CFR 830.2; however,

“destroyed” can be defined as any damage in which repair costs

 	

 
















	
		


	




 

	

 	

Annual Review of Aircraft Accident Data 18

FLIGHT PLAN

Most pilots (1,594) who were involved in accidents in 1998 did

not file a flight plan. In most cases, a flight plan is required only

for flight under instrument flight rules (IFR); however, pilots

operating under visual flight rules (VFR) on point-to-point flights

can also file a flight plan to aid search and rescue efforts if they

fail to arrive at their intended destinations. The relationship

between the filing of flight plans and weather-related accidents

is also discussed in the special topic section of this report.

AIRPORT INVOLVEMENT

Accident locations were closely split between those occurring

away from an airport (50.7%) and those occurring on an airport

or airstrip (45.8% combined). Accidents that occur on an airport

or airstrip typically involve aircraft at relatively low altitudes and

airspeeds that are taking off, landing, or maneuvering to land.

Accidents that occur away from an airport may include aircraft in

all phases of flight, at all altitudes, and at all airspeeds. Because

of these potential differences, accidents that occur away from an

airport are more likely to result in higher levels of injury and

aircraft damage. As the graph below shows, most fatal accidents

(79.1%) occurred away from an airport or airstrip.
ACCIDENT INJURIES

Safety Board investigators categorize injuries resulting from

general aviation accidents as “fatal,” “serious,” or “minor.” Title

49 CFR 830.2 defines a fatal injury as “any injury which results

in death within 30 days of the accident.” Title 49 CFR 830.2 also

outlines several qualifications31 of serious injury that include, but

are not limited to, hospitalization for more than 48 hours, bone

fracture, internal organ damage, or second- or third-degree burns.

The following graph depicts the percentage of each injury category

for general aviation accidents in 1998.32 Most notable is the

fact that more than half (53.9%) of general aviation accidents

do not result in injury.

30 Missing or unrecoverable aircraft are also considered “destroyed.”

31 See Appendix A for the complete definition of injury categories.

32 Injury level is defined for accident aircraft as the highest level of injury sustained.

 	
 




	




















1998 in Depth 19

would exceed the value of the aircraft,30 and “minor” damage

as any damage that is not classified as either “destroyed” or

“substantial.”

Most aircraft involved in accidents during 1998 sustained

substantial damage (74.1%), and approximately one quarter of

aircraft (24.6%) were destroyed. “Minor” and “no damage”

classifications each included less than 1% of accident aircraft.

Highest Level of Injury per Accident Aircraft 1998 

Fatal

19.4%

Minor

16.5%

None

53.9%

Serious

10.2%
The following graphs illustrate both the number of accident aircraft

in each injury category and the corresponding number of persons

aboard those aircraft who sustained injuries in each category.

Aircraft injury level is equal to the highest level of injury sustained

by an occupant of that aircraft. Again, most persons who were

aboard general aviation aircraft that were involved in accidents

sustained no injuries.

Injuries by Role for 1998

The following table presents detailed information about the types

of injuries incurred by all persons involved in general aviation

accidents in 1998. The distribution of general aviation accident

injuries varies with the type of operation and the size of aircraft.

All aircraft have a pilot, but the exposure risk for other persons

varies with the occupant load. For example, in 1998, 61 copilots

suffered some level of injury in general aviation accidents, but

the injury rate for copilots was commensurate with that of pilots,

considering that only 5.9% of accidents involved aircraft with a

copilot. As noted previously, most general aviation accidents

involve personal/business flights in single-engine piston aircraft,

which are likely to have only one pilot. Because of this exposure

difference, pilots sustained the highest percentage of injuries in

Number of Accident Aircraft by

Highest Level of Injury 1998 

195

1,026

318

0

500

1000

1500

2000

Injuries Sustained by Persons Aboard

Accident Aircraft 1998 

321

1,915

551 618

0

500

1000

1500

2000

Fatal Serious Minor None Fatal Serious Minor None

364

Personal Injuries Fatal Serious Minor None Total

 Pilot 345 171 310 1,102 1,928

 Copilot 32 13 16 52 113

 Flight engineer 0 0 0 2 2

 Dual student 10 7 16 77 110

 Check pilot 1 0 2 4 7

 Other crew 12 4 4 11 31

 Flight attendant 0 0 0 1 1

 Passenger 218 126 203 666 1,213

 Total aboard 618 321 551 1,915 3,405

 On ground 5 5 9 0 19

 Other Aircraft 1 1 0 9 11

 Total 624 327 560 1,924

In addition to injuries sustained by persons on board the accident

aircraft, 19 persons who were not aboard accident aircraft also

sustained injuries. Examples of accidents in 1998 that resulted

in fatal injuries to persons not aboard an aircraft include

occupants of a van killed when it collided with an aircraft making

an emergency landing on a highway and a utility worker killed

when a helicopter being used to attach power lines collided with

a utility pole.

Annual Review of Aircraft Accident Data 20

general aviation accidents in 1998, suffering 55.3% of all

fatalities, 52.3% of all serious injuries, and 55.4% of all minor

injuries.
Accident-involved Pilots

RATING

Of the 1,928 pilots involved in general aviation accidents in

1998, the largest percentage (44.6%) held a private pilot

certificate.33 The second-largest percentage (36.1%) held a

commercial pilot certificate, which is required for any person to

act as pilot-in-command of an aircraft for compensation or hire.34

33 FAA, U.S. Civil Airmen Statistics, available at <http://api.hq.faa.gov/CivilAir/index.htm>. 34 See 14 CFR 61.133 for the privileges granted by a commercial pilot certificate.

Highest Rating Held by Accident-Involved Pilot

ATP

10.4%

Commercial

36.1%

Private

44.6%

Student

6.7%

None

0.7%

Unknown

1.5%

When compared to the number of active pilots in 1998 holding

each type of pilot certificate, both private and commercial pilot

certificate holders were over-represented in general aviation

accidents. The 39% of active pilots with private pilot certificates

accounted for 44.6% of accidents, and the 20% of active pilots

with commercial pilot certificates accounted for 36.1% of

accidents.

 	
 
 





	







	



	



	




1998 in Depth 21
As the following graph shows, the accident rate per 1,000 active

pilots was highest for commercial pilot certificate holders, who

can be employed as pilots and are likely to fly more hours annually

than student or private pilots. Annual flight-hour data for pilots

holding each type of certificate are not available to confirm this

conclusion. The U.S. Civil Airmen Statistics compiled by the FAA35

also do not include information about the type of operation that

certificate holders engage in, but examples of commercial

operations include corporate executive transportation, flight

instruction, sightseeing flights, banner towing, and aerial

application.

35 FAA, U.S. Civil Airmen Statistics, 1998, available online at <http://api.hq.faa.gov/CivilAir/index.htm>.

36 Refer to 14 CFR 61, Subpart G, for the privileges and limitations of the ATP certificate.

37 See 14 CFR 121.437

Accident Rate per 1,000 Active Pilots

0

1

2

3

4

5

6

Student Private Commercial ATP

Annual Review of Aircraft Accident Data 22

The largest percentage of commercial pilots involved in accidents

during 1998 (41.8%) were conducting personal flights and were

not involved in commercial operations at the time of the accident.

Airline Transport Pilot (ATP) certificate holders, in addition to being

employed as pilots,36 can engage in air carrier operations,37

which are not included in this review; therefore, ATP certificate

holders may fly fewer general aviation hours and have a lower

general aviation accident rate.

TOTAL TIME

Of the 1,865 accidents in 1998 for which pilot total flight

experience data are available, 887 (47.6%) involved pilots with

fewer than 1,000 hours of flight time. The inset chart on the next

page depicts the distribution of experience among those accident

pilots with fewer than 1,000 hours. The largest percentage of

accident pilots in this group had fewer than 100 hours of total

flight time, and a total of 449 pilots had 300 hours or fewer.

When compared to the total number of accident pilots, those

with 300 hours or fewer accounted for 24.1% of all accident

pilots for whom data are available.
Not surprisingly, most accident pilots with fewer than 300 total

hours of flight time held private pilot certificates;38 the secondhighest percentage held student pilot certificates. Most pilots

with more than 1,000 total hours of flight time held commercial

pilot certificates, followed next by those with private pilot

certificates, and last by those with ATP certificates. Three accident

pilots with more than 1,000 hours total time held only student

pilot certificates.

1998 in Depth 23

Pilot Certificate Held by Accident Pilots with 

Fewer Than 300 Hours Total Flight Time

Private

70.4%

Student

27.2%

None

1.1%

Commercial

1.3%

Pilot Certificate Held by Accident Pilots with

More Than 1,000 Hours Total Flight Time

Commercial

54.6%

None

0.1% ATP

20.5%

Student

0.3%

Other / 

Unknown

0.6%

Private

23.9%

38 Refer to 14 CFR Part 61 for the requirements of each type of pilot certificate and to 14 CFR 141 for changes to those requirements for training conducted at approved flight

schools.
Annual Review of Aircraft Accident Data

It is also not surprising that most accident pilots with fewer than

300 hours total flight time were flying single-engine piston

airplanes when the accidents occurred. Accident pilots with more

than 1,000 hours were flying a more diverse selection of aircraft,

including 14.4% who were flying helicopters.

Aircraft Type Flown by Pilots with Fewer Than 300 

Hours Total Flight Time

0.4%

3.1%

4.7%

0.0%

0.0%

1.1%

4% 90.

Balloon

Glider

Rotorcraft

Airplane Turbojet

Airplane Turboprop

Airplane Multi-engine Piston

Airplane Single-engine Piston

Aircraft Type Flown by Pilots with More Than 

1,000 Hours Total Flight Time

0.4%

1.4%

14.4%

2.7%

6.6%

10.4%

63.3%

Balloon

Glider

Rotorcraft

Airplane Turbojet

Airplane Turboprop

Airplane Multi-engine Piston

Airplane Single-engine Piston

TIME IN TYPE OF AIRCRAFT

Of the 1,609 accidents in 1998 for which data are available

about pilot experience in the accident aircraft make and model,

83.5% involved pilots with fewer than 1,000 hours of time in the

accident aircraft make and model. The inset chart depicts the

distribution of experience among those accident pilots with fewer

than 1,000 hours in type. The largest percentage of accident

pilots in this group (51%) had fewer than 100 hours of total flight

time in the accident aircraft type, and a total of 103 pilots (6.4%

of all accident pilots for whom data are available) had fewer

than 10 hours in type.

Two types of pilots may have low time in type: new pilots with low

total time and more experienced pilots who are transitioning to a

new aircraft. Most accident pilots with fewer than 10 hours of

flight time in make and model were flying single-engine piston

aircraft. The percentage of accident pilots with low time in make

and model who were flying gliders is also worth noting and is

24
1998 in Depth

probably due to the shorter durations typical of glider flights

compared to those of powered aircraft.

Two types of pilots who might be expected to have accumulated

significant time in make and model are those who own their own

airplanes and fly them often and professional pilots who fly the

same aircraft often. A large number of general aviation pilots

who own aircraft have single-engine piston airplanes. Helicopters

and multi-engine piston, jet, and turboprop airplanes are more

likely to be operated by professional pilots. Comparison of the

two graphs that follow shows that pilots with more than 100 hours

in make and model were more likely than pilots with fewer hours

in type to be flying rotorcraft, or multi-engine piston, jet, or

turboprop airplanes.

Aircraft Type Flown by Pilots With Less Than 10 

Hours Flight Time in Make/Model

1.0%

6.8%

5.8%

0.0%

1.0%

5.8%

79.6%

Balloon

Glider

Rotorcraft

Airplane Turbojet

Airplane Turboprop

Airplane Multi-engine Piston

Airplane Single-engine Piston

Aircraft Type Flown by Pilots With More Than 100 

Hours Flight Time in Make/Model

1.0%

1.2%

12.1%

1.5%

6.1%

7.8%

70.3%

Balloon

Glider

Rotorcraft

Airplane Turbojet

Airplane Turboprop

Airplane Multi-engine Piston

Airplane Single-engine Piston

AGE

The next two graphs illustrate the age distribution of pilots

involved in accidents during 1998. Most accident pilots were

between the ages of 50 and 59. The average age of all active

pilots in the U.S. increased steadily from 1988 to 1998 and was

equal to 43.839 years in 1998. Because flight-hour activity

numbers are not available for each age group, no meaningful

inferences can be made regarding specific age-related accident

risk.

39 FAA, U.S. Civil Airmen Statistics, 1998, available at http://api.hq.faa.gov/Airmen/Air13-97.pdf.

25
Pilot Age

0

100

200

300

400

500

600

14-19 20-29 30-39 40-49 50-59 60-69 70+ Unknown

Number of Pilots

All Accidents

Fatal

Accidents

Average Age of Active U.S. Pilots

40.2 40.5 40.5 40.8 41.3 41.9 42.9 43.2 43.6 43.8

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Medical Certificate Held by Accident Pilot

2.1% 1.3% 0.3%

3.6%

35.7%

56.9%

2.8% 1.7% 0.4%

4.0%

41.7%

49.4%

0%

10%

20%

30%

40%

50%

60%

70%

Expired None Not Valid Unknown Valid / No

Waivers

Valid w/

Waiver(s)

1998 1988-1997 Average

MEDICAL CERTIFICATION

The following graph depicts the percentage of accident pilots

who held medical certificates in 199840 and the average

percentage of accident pilots who held medical certificates for the

preceding 10-year period.41 Almost all (92.6%) of the pilots involved

in accidents during 1998 held valid medical certificates. Of those,

56.9% held medical certificates with waivers, and 35.7% held medical

Annual Review of Aircraft Accident Data 26

40 Medical certification as required by 14 CFR 61.23.

41 Pilots of gliders and lighter-than-air aircraft are not required to have medical certification.
42 Title 14 CFR 67 prescribes the medical standards and certification procedures for issuing medical certificates for airmen and for remaining eligible for a medical certificate.

Title 14 CFR 67.401 covers the authorization for special issuance of medical certificates. Pilots who fail to meet the required standards for medical certification may in some

cases be granted an Authorization for Special Issuance of a Medical Certificate, commonly referred to as a waiver. Conditions requiring a waiver range from vision or hearing

deficiencies to insulin-dependent diabetes or heart disease.

43 Graph does not include data for accident pilots with invalid, expired, or no medical certificates.

certificates with no waivers.42 In comparison to the historical

averages, the percentage of accident pilots with waivers on their

medical certificates increased by 7.5%, and the percentage of

accident pilots holding medical certificates with no waivers

decreased by 6%. Data about the total number of active pilots

holding medical certificates with and without waivers, and the

details of any waivers issued, were not available.

As depicted in the following graph,43 the percentage of accident

pilots holding valid medical certificates with no waivers generally

decreased, and the number of accident pilots holding certificates

with waivers generally increased, between 1989 and 1998.

Although data are not available about the total number of active

pilots with and without medical waivers, the observed trend

suggests that the number of active pilots with medical certificate

waivers is increasing. Any increase in the number of pilots with

medical certificate waivers between 1989 and 1998 may be

related to the increasing average age of pilots observed during

those years. Without specific information about details of any

waivers issued, the data are insufficient to suggest a link between

medical waivers and pilot accident risk.

Percent of Accident Pilots with and without Medical Waivers

1989 - 1998 

0%

10%

20%

30%

40%

50%

60%

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

With

Waivers

No

Waivers

Unknown

1998 in Depth 27
44 Two of the codes, “missing aircraft” and “undetermined,” do not represent operational events.

Accident Occurrences for 1998

The circumstances of an accident occurrence are documented

in the Safety Board’s accident report as the “sequence of events.”

The sequence of events can be defined as what happened during

the accident. Sequence of events was first used as a method for

classifying accidents in 1982. A total of 5444 occurrence codes

are available to describe the events for any given accident.

Because aviation accidents are rarely limited to a single event,

each accident is coded as a sequence of events (that is,

occurrence 1, occurrence 2, etc.), with as many as five different

event codes. Of the 1,894 accidents in 1998 with sequence of

events data available, 638 had 2 or more occurrences, 446 had

Annual Review of Aircraft Accident Data 28

Occurrence #1: LOSS OF ENGINE POWER(PARTIAL) - NONMECHANICAL

Phase of Operation: CRUISE

Findings

1. (C) FLUID,FUEL - CONTAMINATION,OTHER THAN WATER

2. (C) FLUID,FUEL - CONTAMINATION,WATER

----------

Occurrence #2: IN FLIGHT COLLISION WITH OBJECT

Phase of Operation: EMERGENCY DESCENT/LANDING

Findings

3. (F) OBJECT - TREE(S)

----------

Occurrence #3: IN FLIGHT COLLISION WITH TERRAIN/WATER

Phase of Operation: EMERGENCY LANDING

Findings

4. (F) TERRAIN CONDITION - NONE SUITABLE

Findings Legend: (C) = Cause, (F) = Factor

The National Transportation Safety Board determines the probable cause(s) of this accident/incident as follows.

A loss of engine power while in cruise flight caused by a contaminated fuel supply and the subsequent inflight collision with trees and unsuitable terrain during the emergency descent and landing.

3 or more, 48 had 4 or more, and 2 had a total of 5 occurrences

(each) coded in the accident sequence of events. Each accident

event includes information about sequential order of its

occurrence. For example, one accident in 1998 involved an

aircraft that lost engine power due to contaminated fuel. The

aircraft began an emergency descent and then collided with trees

before landing on unsuitable terrain. Each of these events was

coded with “loss of engine power” coded as the first occurrence.

An excerpt from the brief report for that accident is included here

as an example of how occurrences are coded.
The following table displays the first occurrences for all of the 1998 general aviation accidents with sequence of events data

available.

1998 in Depth

29

Total Fatal Total Fatal

300 107 507 53

In Flight Collision With Object 154 49 Loss of Engine Power 195 14

In Flight Collision with Terrain/Water 96 35 Loss of Engine Power (Total) - Nonmechanical 156 14

Midair Collision 27 21 Loss of Engine Power (Total) - Mech Failure/Malfunction 68 10

Undershoot 15 1 Loss of Engine Power (Partial) - Mech Failure/Malfunction 44 6

Dragged Wing, Rotor, Pod, Float or Tail/Skid 8 1 Loss of Engine Power (Partial) - Nonmechanical 33 6

Near Collision Between Aircraft 0 0 Rotor Failure/Malfunction 7 3

Propeller Failure/Malfunction 4 0

488 181 Engine Tearaway 0 0

Loss of Control - In Flight 272 108

Airframe/Component/System Failure/ Malfunction 108 16 35 0

In Flight Encounter With Weather 89 48 Wheels Up Landing 12 0

Abrupt Maneuver 10 6 Gear Collapsed 7 0

Forced Landing 5 0 Main Gear Collapsed 7 0

Vortex Turbulence Encountered 2 2 Gear Retraction on Ground 4 0

Altitude Deviation, Uncontrolled 1 0 Nose Gear Collapsed 3 0

Decompression 1 1 Complete Gear Collapsed 1 0

Wheels Down Landing in Water 1 0

122 2 Tail Gear Collapsed 0 0

On Ground/Water Collision with Object 56 1 Other Gear Collapsed 0 0

On Ground/Water Encounter with Terrain/Water 41 1 Gear Not Extended 0 0

Collision Between Aircraft (Other than Midair) 21 0 Gear Not Retracted 0 0

Dragged Wing, Rotor, Pod, Float or Tail/Skid 4 0

28 4

410 8 Miscellaneous/Other 18 3

Loss of Control -On Ground 216 2 Fire 9 1

Hard Landing 106 1 Explosion 1 0

Overrun 42 2 Fire/Explosion 0 0

Nose Over 24 0 Hazardous Materials Leak/Spill 0 0

Roll Over 8 0 Cargo Shift 0 0

Propeller/Rotor Contact to Person 7 3

On Ground Encounter with Weather 5 0 4 4

Nose Down 1 0 Missing Aircraft 3 3

Propeller Blast or Jet Exhaust/Suction 1 0 Undetermined 1 1

Ditching 0 0

Undetermined

Collision - Inflight

Noncollision - Inflight

Collision - On-Ground or Water

Noncollision - On-Ground or Water

Power Related

Landing Gear

Miscellaneous

1998 Accident First Occurrences 
Among the categories of first occurrences, the largest portion of

accidents (26.8%) included occurrences related to aircraft power.

Among the subcategories, the most common first occurrences

involved a loss of control either in flight (14.4%) or on the ground

(11.4%). Although loss-of-aircraft-control-on-the-ground

occurrences resulted in only 2 fatal accidents, loss-of-control-inflight occurrences resulted in a total of 108 fatal accidents, which

was 29.8% of all fatal accidents with available data and more

than twice as many as for any other single occurrence.

Phase of Flight

The illustration below displays the percentage of accident aircraft in

each phase of flight at the time of first occurrence. The phase of

flight can be defined as when, during the operation of the aircraft,

the first occurrence took place. There are 50 distinct phases-offlight that investigators may use to describe the operational

chronology of occurrences. To simplify the presentation of this

information, the detailed phases have been grouped into eight broad

phase categories for this illustration. For example, the category

“approach/landing” includes any segment of an instrument approach

or position in the airport traffic pattern and continues through the

landing until the aircraft clears the runway. The upper set of numbers

represents the percentage of all accidents that occurred in each

phase, and the numbers in parentheses indicate fatal accidents.

Standing Taxi Manuevering / 

Hovering

Not Reported / 

Other

1.0% 3.0% 13.3% 1.4%

( 0.8% ) ( 0.5% ) ( 23.9% ) ( 5.9% )

Accident Aircraft Phase of Flight During First Occurrence 1998

( 20.1% ) ( 31.9% ) ( 16.9% )

Takeoff / Climb Cruise / Descent Approach / 

Landing

24.0% 18.6% 38.7%

As depicted in the illustration, most accidents occurred during

landing and takeoff, despite the relatively short duration of these

phases in comparison to the entire profile of a normal flight.

The high number of accidents that occur during takeoff and

landing reflects the increased workload placed on both the flight

crew and the aircraft during these phases. During takeoff and

landing, the flight crew must control the aircraft while changing

altitude and speed, communicating with air traffic control (ATC)

and/or other aircraft, and maintaining separation from obstacles

and other aircraft. Aircraft systems are also stressed during takeoff

and landing with changes in engine power settings, changes in

cabin pressurization, and the possible operation of retractable

landing gear, flaps, slats, and spoilers. While the aircraft is at

low altitude during takeoff and landing, it is also most susceptible

to any hazards caused by wind and weather conditions.

Notably, the largest percentage of total accident first occurrences

(38.7%) happened during the approach/landing phase of flight,

but only 16.9% of fatal accident first occurrences happened during

this phase. The largest percentage of fatal accident first

occurrences (31.9%) occurred during the cruise/descent phase

of flight, but only 18.6% of all accident first occurrences occurred

during this phase. These statistics reflect the relative severity of the

types of accidents that are likely to occur during each of these

phases. Accidents during cruise/descent are more likely to result

in higher levels of injury and

aircraft damage due to the

higher speeds and altitudes

associated with these phases

of flight.

Annual Review of Aircraft Accident Data 30
1998 in Depth 31

The likelihood of an aircraft accident first occurrence during each

phase of flight varies with different aircraft types and types of

flying. For example, single-engine piston aircraft used for

instructional flights fly more takeoffs and landings as new pilots

practice these skills. As a result, 51% of all first occurrences for

1998 accidents involving single-engine aircraft on instructional

flights occurred during the approach/landing phase. In contrast,

the largest percentage of first occurrences for accidents involving

aerial application flights occurred during the maneuvering phase

of flight, reflecting the hazards associated with low altitude

operations.

Most Prevalent Causes/Factors for 1998

PROBABLE CAUSES, FACTORS, FINDINGS, AND THE BROAD CAUSE/

FACTOR CLASSIFICATION

In addition to coding accident occurrences, the Safety Board is

required to make a determination of probable cause. The

objective of this determination is to discern the cause-and-effect

relationships in the accident sequence. This could be described

as why the accident happened. In determining probable cause(s)

of an accident, the Safety Board considers all facts, conditions,

and circumstances. The term “factor” is used to describe

situations or circumstances that contributed to the accident. For

example, if the cause of an accident were the malfunction of the

aircraft brakes, which caused the aircraft to slide off the end of

the runway, environmental conditions might be cited as a “factor”

if the braking problem were made worse by a wet runway. Any

additional information that is neither a cause nor a factor but

that further supplements the explanation of an accident is indicated

as a “finding.” The details of probable cause are coded as the

combination of all causes, factors, and findings associated with

the accident. Just as accidents often include a series of events,

many factors often combine to cause an accident. For this reason,

a single accident report can include multiple cause and factor

codes. In many cases, an accident record will have a single cause

and multiple factors.

To simplify the presentation of probable cause information, the

hundreds of unique codes have been grouped into broad cause/

factor categories. This broad cause/factor classification provides

an overview of fundamental accident origins by dividing all

accident causes and factors into three groups: aircraft,

environment, and personnel. The following graph depicts the

number of general aviation accidents that fall into each broad

cause/factor and cause classification. Personnel-related causes

or factors were cited in 89.9% of all general aviation accident

reports for 1998 for which cause/factor data were available

(N=1,867). Environmental causes/factors were cited in 44% of

these accident reports, and aircraft-related causes/factors were

Cause/Factors and Causes of General Aviation

Accidents 1998

(1,867 accidents with attributed cause)

564

822

1,679

448

66

1,621

Aircraft Environment Personnel

Cause or Factor Cause only
45 Because the Safety Board frequently cites multiple causes and factors for an aircraft accident, adding together the number of causes and factors will result in a sum that is

greater than the total number of accidents.

46 “Powerplant/propulsion” causes and factors include any partial loss or disruption of engine power, as well as the malfunction or failure of any part(s), equipment, or system

associated with engine propulsion, while “engine power loss” refers only to the total loss of engine power.

Accident Cause/Factors 1998

128

2

13

16

30

35

57

66

158

265

564

56

92

182

369

371

822

18

17

186

1,567

1,679

 Engine power loss

 Instruments

 Aircraft performance

 Flight control systems

 Systems and equipment

 Aircraft structure

 Landing gear

 Fluid

 Powerplant/propulsion

 Airport/airways facilities, aids

 Light condition

 Object

 Terrain condition

 Weather condition

 Organizations

 Others (aboard)

 Others (not aboard)

 Pilot

All Personnel Related

All Environment Related

All Aircraft Related

Undetermined

cited in 30.2% of reports.45 Environmental conditions are rarely

cited as an accident cause but are more likely to be cited as a

contributing factor. In 1998, only 66 of 822 environmental

citations (8% of all environmental causes/factors) were listed as

a cause, with the remainder listed as contributing factors.

The following graph displays the causes/factors of the 1998

accidents with available information. Although several hundred

unique codes are available to document causes/factors, this graph

summarizes them by the broad cause and factor categories of

personnel, environment, and aircraft and by the next-lower-level

subcategory.

This graph clearly shows that most causes and factors attributed

to general aviation accidents are personnel related. The pilot

was the most frequently cited individual in the personnel category;

however, other persons not aboard the aircraft were cited as a

cause or factor in 186 accidents. Examples of accident-related

personnel not aboard the aircraft could include an

air traffic controller, a maintenance technician, or

airport personnel. In the broad category of

environmental factors, weather conditions were cited

in a total of 371 (19.5%) accidents. Powerplantrelated46 causes/factors were the most commonly

cited factors within the broad category of aircraft and

were cited in 265 (13.9%) of the general aviation

accidents in 1998.

The following graph shows that specific accident causes

and factors can vary for different types of aircraft. For

example, environmental causes and factors were cited

in 45.2% of accidents involving single-engine piston

airplanes, compared to 32.1% and 33.3% respectively

for multi-engine piston and turbine airplanes. Because

single-engine piston airplanes are smaller, fly at lower

altitudes, and usually have less-sophisticated avionics,

environmental conditions like wind and weather pose

a greater hazard than to larger aircraft. However,

because of the complexity of the systems and equipment

Annual Review of Aircraft Accident Data 32
1998 in Depth 33

HUMAN PERFORMANCE

The information recorded in the personnel category refers

primarily to whose actions were a cause or factor in an accident.

To increase the level of detail about the actions or behavior that

may have led to an accident, causal data related to human

performance issues and any underlying explanatory factors

are also recorded. The information in these categories can be

thought of as how and why human performance contributed to

the accident. For example, if a pilot became disoriented and

lost control of the aircraft after continuing a visual flight into

Cause/Factors of General Aviation Accidents by Aircraft Type 1998

28.1%

33.6%

41.2% 40.9%

45.2%

32.1% 33.3% 37.5%

91.2% 91.8% 92.2%

84.1%

Single-engine Piston Airplane

Turbine Airplane

Multi-engine Piston Airplane

Helicopter

Aircraft Environment Personnel

instrument flight conditions, the pilot would be cited as “cause”in

the personnel category, and planning/decision-making would

likely also be cited in the human performance issues category.

Of the 1,570 accidents for which the cause or factor was attributed

to human performance, the most frequently cited cause/factor was

aircraft handling and control (64.2%), followed by planning and

decision-making (38.2%), and use of aircraft equipment (14.6%).

Issues related to personnel qualification were cited in 48.1% of

the 283 accidents with underlying explanatory factors related to

human performance. Examples of qualification issues that were

cited in the 1998 accident record include lack of experience,

inadequate training, and the use of unfamiliar equipment.

in larger aircraft, they may be more sensitive to failures. As the

graph illustrates, aircraft causes and factors were cited in only

28.1% of accidents involving single-engine piston airplanes,

compared to 33.6% for multi-engine piston airplanes, 41.2%

for turbine-powered airplanes, and 40.9% for helicopters.

Percentages of accidents citing personnel causes and factors were

similar for all airplane types and only slightly lower for accidents

involving helicopters.

Cause / Factor Cause

Human Performance Issues 1,570 1,506

 Aircraft handling/control 1,008 954

 Planning/decision 600 507

 Use of aircraft equipment 229 196

 Maintenance 132 90

 Communications/information/ATC 69 46

 Meteorological service 14 5

 Airport 5 2

 Dispatch 0 0

Underlying Explanatory Factors 283 58

 Qualification 136 8

 Psychological condition 65 12

 Physiological condition 58 25

 Aircraft/equipment inadequate 16 6

 Institutional factors 10 2

 Material inadequate 9 3

 Information 6 0

 Procedure inadequate 6 4

 Facility inadequate 1 0

Note: due to the possibility of multiple findings, the sum of cause/factors is greater

than the accident total.
GENERAL AVIATION SAFETY ISSUES

This section discusses several issues particularly relevant to general

aviation safety. It is not meant to be an exhaustive discussion of

all safety concerns, but rather a sample of the issues important

to general aviation.

Survivability

Because of their relatively small size, low gross weight, and lower

cost, most general aviation aircraft have not received some of

the cabin safety enhancements available to larger commuter and

transport-category aircraft. Examples of enhancements include

fire suppression systems and improved fire retardant materials,

redesigned restraint systems and seats, and improved impactabsorbing materials.47 In addition, due to the high average age

of the general aviation fleet—27 years—enhancements that have

47 See 14 CFR 23.853 for passenger and crew interior compartment design requirement differences among normal, utility, acrobatic, and commuter aircraft categories.

Percent of General Aviation Accidents Resulting in a Fatality

1983-1998 

0%

10%

30%

40%

50%

60%

70%

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

20%

been made in recent years to newly manufactured aircraft have

affected relatively few aircraft. As a potential consequence, the

percentages of general aviation accidents resulting in a fatality

have fluctuated only slightly since 1983, remaining at

approximately 18-21% throughout the period.

Pilot behaviors related to improving survivability of accidents have

increased noticeably over the last 10 years. For example, the number

of accident pilots who wear seatbelts has increased steadily since

1989, as the following graph shows.

Seatbelt Usage by Accident Pilots 1989-1998

0%

10%

20%

30%

40%

50%

60%

70%

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Accident

Wearing

Seatbelt

Accident no

Seatbelt

Unknown

Annual Review of Aircraft Accident Data 34
35

48 Increased seatbelt use may also reduce the number of injuries resulting from in-flight encounters with turbulence and/or weather, but these data are not currently available.

49 See National Transportation Safety Board safety reports General Aviation Crashworthiness Project, Phase One NTSB/SR-83/01 (Washington, DC: NTSB, 1983), Phase

Two, NTSB/SR-85/01, (Washington, DC: NTSB, 1985), and Phase Three, NTSB/SR-85/02 (Washington, DC: NTSB, 1985).

50 GAMA, General Aviation Statistical Databook, 2001.

However, despite the observable increase in seatbelt use by pilots

over the last 10 years, the following graph illustrates that the

distribution of accident injuries has not changed meaningfully

since 1989.48 This stability in injury and fatality rates despite

changes in pilot behavior suggests 1) that a subset of accidents

remains “unsurvivable,” regardless of seatbelt and shoulder

harness use, due to the speed and/or angle of impact,49 and

2) that the severity of nonfatal accident injuries may depend upon

aircraft cabin safety features that in most cases reflect the 27-

year average age50 of the general aviation fleet.

Aircraft-specific factors, such as size, weight, and speed, can

contribute both directly and indirectly to the severity of accident

injuries. Higher speed contributes directly to accident injury

because it results in higher impact force.

The size and weight of an aircraft can have an indirect effect on

accident injury. Larger, heavier aircraft are typically not used

for flight instruction, aerial application, and personal

pleasure, and are not exposed to the same types of situations as

smaller aircraft, nor are they involved in exactly the same types

of accidents. At the same time, smaller, lighter aircraft may not

have the same cabin safety features and fire suppression

equipment as the larger aircraft. Because of these differences in

design, construction, and typical operation, accident injury level

can vary with the type of aircraft. Evidence for these differences

is illustrated in the following graph, which shows the percentage

of accidents by injury level for each aircraft type in 1998. For

example, 17.9% of accidents in 1998 involving single-engine

piston aircraft were fatal, compared to 34.8% of accidents

involving jet aircraft. This does not suggest that jet aircraft are

more dangerous than single-engine aircraft; rather, it is an

indication of the circumstances of the accidents in which each

type of aircraft is likely to be involved. Single-engine piston aircraft

are more likely to be involved in accidents during takeoff and

landing due to crosswinds or weather conditions than are the

larger, heavier jet aircraft. These accidents are usually at low

1998 in Depth

 	
 
  

 	
 
 














         

	

	

	

 
 	
 
   
  

 	
 
 
















	



	

	 	 ! "		
 #
 $		

%	

	

	

&

51 A total of 30 aircraft were involved in 15 midair collisions. However, one of the aircraft involved was a military helicopter, and two were conducting Part 135 operations

and are not included in this report.

52 Of the aircraft involved in midair collisions, 21 had at least one fatality.

Annual Review of Aircraft Accident Data 36

speeds and less likely to cause severe injury. In contrast, jet

aircraft are larger and heavier and therefore less likely to be

involved in accidents associated with crosswinds and wind gusts.

However, any accidents in which jet aircraft are involved are likely

to occur at higher speeds and are therefore likely to result in

more severe injuries.

Midair Collisions

In 1998, 27 general aviation aircraft were involved in 15 midair

collision accidents.51 Twelve52 of these accidents were fatal,

resulting in a total of 26 deaths. The number of midair collisions

in 1998 was unchanged from the previous year when 15 midair

collisions occurred; of these accidents, 11 were fatal and resulted

in 29 deaths. The number of midair collisions occurring annually

has fluctuated between 1983 and 1998, with a general decline

in the number of such accidents from a peak observed in 1986.

 		
 




















  	 
        	 
 


  


Total GA Midair Fatalities 1983-1998

0

20

40

60

80

100

120

140

160

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Of the 27 general aviation aircraft involved in midair collisions

during 1998, 24 were airplanes, 2 were helicopters, and 1 was

a glider. The highest percentage of aircraft involved in midair
General Aviation Safety Issues 37

Midair Collisions by Phase of Flight 1998

Takeoff / Climb Cruise / Descent Maneuvering Approach /

Landing

7.4%

48.1%

11.1%

33.3%

As illustrated in the following graph, two of the aircraft involved

in midair collisions were in Class B airspace at the time, and four

were in Class D53 airspace. Class B and Class D are both

examples of controlled airspace that require pilots to communicate

with the ATC facility having jurisdiction for that area.54 This

suggests that these failures were not simply due to a lack of ATC

services. Furthermore, all of the midair collisions in 1998

occurred in visual meteorological conditions and daylight

conditions, suggesting that these failures to maintain aircraft

separation were also not due to limited visibility.

 	

   


    

 	
 

















	  	  	  	  	  	  

53 Airspace types are designated in 14 CFR 71. Also see Chapter 3, Sections 1 and 2, of the Aeronautical Information Manual for a detailed description of operating

procedures and requirements of each class of airspace.

54 Class B airspace extends from the surface to 10,000 feet mean sea level and is designated around the busiest airports. All aircraft must be granted an ATC clearance to

operate in Class B airspace and are subject to minimum pilot qualification and aircraft equipment requirements. Class D airspace is designated around airports with an

operating control tower and extends from the surface to 2,500 feet above the airport elevation. See 14 CFR 91.129 for rules governing aircraft operations in Class D

airspace and 14 CFR 91.131 for rules governing aircraft operations in Class B airspace.

Collisions with Terrain or Objects

A unique group of accidents occurs when, during otherwise

normal operations, an aircraft collides with terrain, water, or an

obstacle with no indication of loss of control or engine failure.

The phrase “controlled flight into terrain” (CFIT) is commonly

used to refer to such accidents. Because of the variety of standards

used to designate an accident as CFIT, and the ambiguity

surrounding its definition, it is necessary to specify the standard

being used when presenting CFIT data. The following accident

data were derived using a working definition of CFIT that includes

any accident involving an in-flight collision with terrain, water, or

collisions was for aircraft in cruise flight, while one-third were in

the approach/landing phase of flight. Of the nine aircraft involved

in midair collisions during approach/landing, four were on the

downwind segment of a VFR pattern and four were on final

approach (14.8% each).
an object. The data do not include accidents resulting from a

loss of aircraft control, including uncontrolled altitude deviations,

any total or partial loss of engine power, or engine failure. Also

excluded are accidents that result from a bird strike or that occur

during intentional aerobatic or low-level maneuvers, during

normal or aborted takeoffs, during maneuvers related to landing

or takeoff emergencies, or on the runway.

In 1998, 88 general aviation accidents involved collision with

terrain, water, or objects during controlled flight. Of those 88

accidents, 54 (61.3%) were fatal, in contrast to the 18 to 21%

fatal accident rate observed in general aviation over the last 15

years. CFIT accidents accounted for only 4.6% of the total

number of general aviation accidents in 1998, but 14.9% of the

fatal accidents. Because of their nature, CFIT accidents typically

result in severe injury and aircraft damage.

The following graph presents the number of CFIT accidents and

fatal CFIT accidents that occurred in both instrument and visual

meteorological weather conditions during 1998. The graph

illustrates that most of these accidents, both fatal and non-fatal,

1998 Accidents

(1,904) total

1998 Fatal Accidents

(364) total

CFIT

4.6%

CFIT

14.9%

Percentage of General Aviation Accidents

Involving CFIT 1998

occurred in IMC. The inset graph further illustrates that most of the

CFIT accidents that occurred in IMC involved continued VFR flight

into instrument conditions. In total, continued VFR flight into

instrument conditions accounted for half of all fatal controlled flight

crashes in 1998.

Weather as a Cause/Factor

Because general aviation aircraft are often smaller, slower, and

limited in maximum altitude and range in comparison to transportcategory aircraft, they can be more vulnerable than larger aircraft

to hazards posed by weather. Smaller aircraft are affected to a

greater degree by adverse wind conditions, and precipitation,

icing, and convective weather have a greater effect on aircraft

that lack the speed, altitude, and/or range capabilities to avoid

those conditions. The weather conditions cited most often as a

cause or factor in general aviation accidents are related to winds,

including “crosswind,” “gusts,” and “tailwind.” Of the top 10

causes/factors cited in general aviation accidents in 1998,

 	 

  







 	


	



 
	



	 
	 









 



 	

	
 
  	

Annual Review of Aircraft Accident Data 38
General Aviation Safety Issues 39

Just as most landing accidents do not result in fatal injuries, most

wind-related accidents are also not fatal. Among fatal general aviation

accidents, the most frequently cited weather factors are related to

conditions that result in reduced visibility, including “low ceiling,” “fog,”

and “clouds.” Accidents under conditions of low visibility may

Accidents

Crosswind 87

Gusts 75

Tailwind 46

Low Ceiling 41

High Density Altitude 37

Fog 29

Carburetor Icing Conditions 26

Clouds 23

High Wind 19

Downdraft 16

Obscuration 12

Sudden Windshift 12

Variable Wind 10

Icing Conditions 9

Rain 9

Turbulence 9

Unfavorable Wind 7

Snow 6

Windshear 6

Turbulence, Terrain Induced 6

Haze/Smoke 4

No Thermal Lift 4

Mountain Wave 3

Thunderstorm 3

Drizzle/Mist 3

Turbulence, Clear Air 2

Turbulence In Clouds 2

Turbulence (Thunderstorms) 2

Freezing Rain 2

Whiteout 1

Updraft 1

Microburst/Dry 1

Dust Devil/Whirlwind 1

Weather As Cause / Factor 1998 Fatal Accidents Fatalities

Low Ceiling 33 55

Fog 22 32

Clouds 17 37

High Density Altitude 8 19

Obscuration 8 11

Gusts 7 14

Rain 7 11

Tailwind 6 12

Icing Conditions 5 11

Snow 5 8

Turbulence, Terrain Induced 4 6

Turbulence 3 4

High Wind 2 3

Windshear 2 2

Haze/Smoke 2 5

Thunderstorm 2 4

Drizzle/Mist 2 3

Turbulence In Clouds 2 2

Turbulence (Thunderstorms) 2 6

Freezing Rain 2 2

Crosswind 1 2

Carburetor Icing Conditions 1 1

Downdraft 1 2

Sudden Winshift 1 1

Mountain Wave 1 1

Turbulence, Clear Air 1 1

Variable Wind 0 0

Unfavorable Wind 0 0

No Thermal Lift 0 0

Whiteout 0 0

Updraft 0 0

Microburst/Dry 0 0

Dust Devil/Whirlwind 0 0

Weather As Cause / Factor 1998

Because of the number of fatal general aviation accidents each

year citing visibility-limiting weather phenomena like clouds, haze,

fog, and mist as a cause or factor, the special topic chosen for

1998 is instrument meteorological conditions. The following

section discusses the issues associated with general aviation

accidents that occur in IMC in greater detail.

5 were related to wind. Aircraft are most susceptible to the effects

of wind during takeoffs and landings, and the effect of adverse

wind is reflected in the high percentage of general aviation

accidents that occur during those phases of flight.

include pilot disorientation, loss of control, or collision with obscured

obstacles or terrain, all of which are likely to result in severe

accidents.
SPECIAL TOPIC

Accidents in Instrument Meteorological Conditions

According to the FAA Pilot/Controller Glossary, “instrument

meteorological conditions” are defined as “Meteorological

conditions expressed in terms of visibility, distance from cloud,

and ceiling less than the minima55 specified for Visual

Meteorological Conditions (VMC).” In many cases, general

aviation flight minima are 3 statute miles flight visibility and 1,000

feet above, 500 feet below, and 2,000 feet distance from clouds.

As the next graph shows, more general aviation accidents occur

during VMC than during IMC. Over the 10-year period from

1989 to 1998, accidents in IMC accounted for 6.8% of all general

aviation accidents. In 1998, the 116 general aviation accidents

that occurred in IMC comprised 6.0% of the total accidents.

Although this proportion may simply reflect general aviation

activity in VMC and IMC, information regarding flight hours by

meteorological condition is not available to support this

conclusion.

55 Minima for visual meteorological conditions are specified in 14 CFR 91.155.

Although accidents in IMC make up a relatively small proportion

of all general aviation accidents, they represent a larger

percentage of fatal accidents. Over the 10-year period from

1989 to 1998, accidents in IMC accounted for 22.3% of fatal

general aviation accidents. In 1998, 79 fatal IMC accidents

accounted for 21.2% of all fatal general aviation accidents.

40

0

100

200

300

400

500

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

IMC VMC Unk/NR

Fatal General Aviation Accidents in IMC and VMC

General Aviation Accidents in IMC and VMC

0

500

1000

1500

2000

2500

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

IMC VMC Unk/NR
41

 	 

       













    	  
   


 


56 Title 14 CFR 91.173 states, “No person may operate an aircraft in controlled airspace under IFR unless that person has (a) Filed an IFR flight plan; and (b) Received an

appropriate ATC clearance.”

57 One of these pilots had filed a VFIF flight plan, which is a combination IFR/VFR flight plan.

 	
 
   
  





	
 
















	




An IFR flight plan is required to fly in IMC;56 however, in 1998,

only 36 of 116 pilots involved in IMC accidents had filed an IFR

flight plan.57 In 64 accidents (55.2%), no flight plan had been

filed, and in 14 cases (12.1%), only a VFR flight plan had been

filed. This suggests that most pilots in these accidents were

unaware of the possibility and/or risk of flight into IMC.

Although few pilots involved in accidents in IMC had filed an IFR

flight plan, it is possible that they were flying by reference to their

instruments at the time of the accident. However, the following

chart indicates that only 60 (51.7%) of the 116 pilots involved in

accidents in IMC had current instrument ratings.

Correspondingly, accidents in IMC are much more likely to involve

a fatality than accidents in VMC. On average, 65.4% of all IMC

accidents between 1989 and 1998 involved a fatality as opposed

to 16.0% of VMC accidents. In 1998, 68.1% of IMC accidents

involved a fatality as compared to 15.7% of VMC accidents.

Special Topic
 

    



	









	




 	



Furthermore, among the 74 pilots who filed a VFR flight plan or

who had filed no flight plan, only 32.4% were instrument rated.

This suggests that many pilots involved in accidents in IMC are

not qualified for this type of flight.

The following graphs summarize the broad causes and factors of

1998 general aviation accidents occurring in IMC and in VMC.58

As one might expect, accidents that occurred in IMC were more

likely to have environment-related causes/factors. In addition,

although IMC accidents were less likely to be attributed to aircraftrelated causes/factors, they were more likely to be attributed to

personnel-related causes/factors. Finally, for both IMC and VMC,

personnel and aircraft-related issues were more likely to be

reported as causes of accidents, and environmental issues were

far more frequently listed as factors (that is, contributing factors).

58 Of the 1,924 general aviation accidents that occurred in IMC, causal attribution and IMC/VMC data are available for 1,854.

Annual Review of Aircraft Accident Data 42

Accident Cause/Factor 1998 Accidents

Occurring in IMC

(111 accidents with attributed cause)

23.4%

64.9%

97.3%

4.5%

15.3%

96.4%

Aircraft Environment Personnel

Cause/Factor Cause

Accident Cause/Factor 1998 Accidents

Occurring in VMC

(1,743 accidents with attributed cause)

30.8%

42.6%

89.4%

3.5%

24.7%

86.1%

Aircraft Environment Personnel

Cause/Factor Cause
Special Topic 43

The phase of flight during which the first accident occurrence

took place may provide some insight into the planning and

decision-making processes of accident pilots. Although most

accidents tend to occur during takeoff and landing, IMC accidents

do not follow this trend. For this group, the largest proportion of

first occurrences (45.0%) took place during the cruise/descent

portion of flight, suggesting that pilots may not be aware of

upcoming weather/visibility conditions or that those conditions

may have changed during the flight.

 	
	 
	

     

	
	
 
	




  	
	
  


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Phase of Flight During First Occurrence

(1,881 accidents with first occurrence data)

0 100 200 300 400 500 600 700 800

Standing

Taxi

Takeoff/Climb

Cruise/Descent

Maneuvering/Hovering

Approach/Landing

Other/Not Reported

IMC

VMC

59 An attempt was made to investigate pilots’ experience with instrument flight; however, these data were not available in enough cases to permit this analysis.

A total of 1,560 general aviation accidents that occurred in VMC

or IMC had at least one cause or factor attributed to human

performance. Because multiple causes/factors may be attributed

in a single accident, the total number of human performance

attributions within this group was 2,043.

Aircraft handling/control was the most frequently cited cause/

factor within the human performance category; however, although

it accounted for 49.9% of causes/factors in VMC accidents,

handling/control was listed in only 38.6% in IMC accidents.

Conversely, planning and decision-making accounted for 27.6%

of the causes/factors in VMC and 45.5% in IMC. This finding is

not surprising given that many pilots who had accidents in IMC

did not file an IFR flight plan. This is further supported by the

types of planning and decision-making factors listed within this

group, which included “VFR flight into IMC” and other decisions

prior to and during the flight that led to flight into adverse weather.
One possible explanation for pilots’ lack of awareness regarding

the risks of flying in IMC may relate to their lack of flight

experience. However, as shown in the following charts, the

distinction between IMC and VMC accident pilots is not clear

regarding total flight experience59 or pilot age. However,

unsurprisingly, a larger proportion of brand-new pilots (that is,

those with fewer than 100 flight hours) are involved in VMC

accidents, probably because pilots spend their first flights in VMC.

In terms of pilot age, pilots involved in accidents in IMC and

VMC had similar age distributions.

 	
 
    
  















	      
   


	
 
 

 













	      
  





 	 
 
  
 	













 	 	 	 	 

	 

 	






In summary, Safety Board aviation accident data confirm that,

although most general aviation accidents occur during VMC,

IMC accidents are far more likely to include a fatality. A closer

look revealed that most pilots involved in IMC accidents had not

filed a VFR flight plan and only about half had current instrument

ratings.

As expected, accidents that occurred in IMC were more likely

than those that occurred in VMC to be linked to environmental

factors. However, environmental events were rarely identified as

causal to accidents in either group. Rather, for both groups,

most causes were personnel-related. Within the subgroup of

human performance issues, accidents in VMC were most

frequently associated with aircraft handling/control issues, and

IMC accidents were most often related to planning and decisionmaking. This might suggest that pilots involved in accidents in

IMC lacked flight experience. However, analyses of age and

total flight hours data did not clearly support this theory.

Annual Review of Aircraft Accident Data 44
45

APPENDIX A

Definitions

DEFINITIONS OF SAFETY BOARD SEVERITY CLASSIFICATIONS

The severity of a general aviation accident is classified by the

highest level of injury (that is, fatal, serious, minor, or none) and

level of aircraft damage (that is, destroyed, substantial, minor, or

none).

DEFINITIONS FOR HIGHEST LEVEL OF INJURY

Fatal - Any injury that results in death within 30 days of the

accident.

Serious - Any injury that (1) requires the individual to be

hospitalized for more than 48 hours, commencing within 7 days

from the date the injury was received; (2) results in a fracture of

any bone (except simple fractures of fingers, toes, or nose); (3)

causes severe hemorrhages, nerve, muscle, or tendon damage;

(4) involves any internal organ; or (5) involves second- or thirddegree burns, or any burns affecting more than 5% of the body

surface.

Minor - Any injury that is neither fatal nor serious.

None - No injury.

60 Title 49 CFR 830.2 does not define “destroyed.” This term is difficult to define because aircraft are sometimes rebuilt even when it is not economical to do so.

61 See 49 CFR 830.2.

DEFINITIONS FOR LEVEL OF AIRCRAFT DAMAGE

Destroyed - Damage due to impact, fire, or in-flight failures to

the extent that the aircraft cannot be repaired economically.60

Substantial Damage - Damage or failure that adversely affects

the structural strength, performance, or flight characteristics of

the aircraft and that would normally require major repair or

replacement of the affected component. Engine failure or

damage limited to an engine if only one engine fails or is

damaged, bent fairings or cowling, dented skin, small puncture

holes in the skin or fabric, ground damage to rotor or propeller

blades, and damage to landing gear, wheels, tires, flaps, engine

accessories, brakes, or wingtips are not considered “substantial

damage.”61

Minor Damage – Any damage that neither destroys the aircraft

nor causes substantial damage (see definition of substantial

damage for details).

None – No damage.
APPENDIX B

The National Transportation Safety Board

Investigative Process

The National Transportation Safety Board investigates every civil

aviation accident that occurs in the United States. It also provides

investigators to serve as U.S.-Accredited Representatives as

specified in international treaties for aviation accidents overseas

involving U.S.-registered aircraft or involving aircraft or major

components of U.S. manufacture.62 Investigations are conducted

from Safety Board Headquarters in Washington, D.C., or from

one of the 10 regional offices in the United States (see Appendix D).

In determining probable cause(s) of an accident, investigators

consider facts, conditions, and circumstances. The objective is

to ascertain those cause and effect relationships in the accident

sequence about which something can be done to prevent

recurrence of the type of accident under consideration.

Note the distinction between the population of accidents

investigated by the Safety Board and those that are included in

the Annual Review of Aircraft Accident Data, U.S. General Aviation.

Although the Safety Board is mandated by Congress to investigate

all civil aviation accidents that occur on U.S. soil (including those

involving both domestic and foreign operators), the Annual Review

describes accidents that occurred among U.S.-registered aircraft

in all parts of the world.

62 For more detailed information about the criteria for Safety Board investigation of an aviation accident or incident, see 49 CFR 831.2.

46
APPENDIX C

The National Transportation Safety Board Aviation

Accident/Incident Database

The National Transportation Safety Board is responsible for

maintaining the government’s database on civil aviation accidents.

The Safety Board’s Accident/Incident Database is the official

repository of aviation accident data and causal factors. The

database was established in 1962 and approximately 2,000 new

event records are added each year.

The Accident/Incident Database is primarily composed of aircraft

accidents. An “accident” is defined in 49 CFR 830.2 as “an

occurrence associated with the operation of an aircraft which

takes place between the time any person boards the aircraft with

the intention of flight and all such persons have disembarked,

and in which any person suffers death or serious injury, or in

which the aircraft receives substantial damage.” The database

also contains a select number of aviation “incidents,” defined in

49 CFR 830.2 as “occurrences other than accidents that are

associated with the operation of an aircraft and that affect or

could affect the safety of operations.”

Accident investigators use the Safety Board’s Accident Data

Management System (ADMS) software to enter data into the

Accident/Incident Database. Shortly after the event, a preliminary

report containing a few data elements, such as date, location,

aircraft operator, type of aircraft, etc., becomes available.

A factual report with additional information concerning the

occurrence is available within a few months. A final report, which

includes a statement of the probable cause and other contributing

factors, may not be completed for months after the investigation

has been completed.

47

An accident-based relational database is currently available

to the public at http://www.ntsb.gov/ntsb/query.asp#query_start.

It contains records of approximately 40,000 accidents and

incidents that occurred between 1982 and the present. Each

record may contain more than 650 fields of data concerning

the aircraft, event, engines, injuries, sequence of accident events,

and other topics. Individual data files are also available for

download at ftp://www.ntsb.gov/avdata, including one complete

data set for each year beginning with 1982. The data files are in

Microsoft Access (.mdb) format and are updated monthly. This

download site also provides weekly “change” updates and

complete documentation.
Anchorage

ALASKA

Parsippany

MID ATLANTIC

Washington DC

Atlanta

SOUTHEAST

Miami

NORTH CENTRAL

Chicago

SOUTH CENTRAL

NORTHWEST Seattle

SOUTHWEST

Gardena

Mid-Atlantic Regional Office

490 L’Enfant Plaza, S.W. 

Washington, D.C. 20594 

Phone: 202-314-6320 

FAX: 202-314-6329

8:30 a.m.-5 p.m. (Eastern) 

 

 

 

 

Southwest Regional Office

1515 W. 190th Street

Suite 555

Gardena, California 90248

Phone: 310-380-5660

FAX: 310-380-5666

7 a.m.-3:30 p.m. (Pacific)

South Central Regional Office 

624 Six Flags Drive 

Suite 150 

Arlington, Texas 76011 

Phone: 817-652-7800 

FAX: 817-652-7803 

7:30 a.m.-4 p.m. (Central) 

Northeast Regional Office

2001 Route 46

Suite 504 

Parsippany, New Jersey 07054

Phone: 973-334-6420 

FAX: 973-334-6759

8:30 a.m.-5 p.m. (Eastern)

Southeast Regional Office

8405 N.W. 53rd Street

Suite B-103 

Miami, Florida 33166 

Phone: 305-597-4610 

FAX: 305-597-4614 

8 a.m.-4:30 p.m. (Eastern) 

Southern Regional Office

Atlanta Federal Center 

60 Forsyth Street, SW

Suite 3M25

Atlanta, Georgia 30303-3104 

Phone: 404-562-1666 

FAX: 404-562-1674

8 a.m.-4:30 p.m. (Eastern)

Northwest Regional Office

19518 Pacific Highway South

Room 201

Seattle, Washington 98188-5493

Phone: 206-870-2200

FAX: 206-870-2219

8 a.m.-4:30 p.m (Pacific) 

Alaska Regional Office

222 West 7th Avenue 

Room 216, Box 11

Anchorage, Alaska 99513

Phone: 907-271-5001

FAX: 907-271-3007

8 a.m.-4:30 p.m (Alaska) 

North Central Regional Office 

31 West 775 North Avenue

West Chicago, Illinois 60185 

Phone: 630-377-8177 

FAX: 630-377-8172 

7:30 a.m.-4 p.m. (Central) 

Central Mountain Regional Office

4760 Oakland Street 

Suite 500 

Denver, Colorado 80239 

Phone: 303-361-0600 

FAX: 303-361-0619

7:30 a.m.-4 p.m (Mountain)

Denver

CENTRAL MOUNTAIN

Arlington

SOUTHERN

NORTHEAST

48

APPENDIX D

National Transportation Safety Board Regional Offices1

1 As of FY 2003