Annual Review of Aircraft Accident Data

U.S. General Aviation, Calendar Year 1999

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-03-02

PB2003-105847
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National Transportation Safety Board

490 LíEnfant Plaza, S.W.

Washington, D.C. 20594

nnual R nnual Review of Aircraft Accident Data eview of Aircraft Accident Data

U.S. General Aviation, Calendar Year 1999

/ARG-03/02

03-105847

ion 7534A

ed May 29, 2003
on Safety Board. 2003. on Safety Board. 2003. U.S. General Aviation, Calendar Year 1999. Annual Review of eview of

NTSB/ARG-03/02. Washington, D.C.

aircraft were involved in 1,906 accidents during calendar year 1999. The total number of general

g in 1999 was virtually unchanged from calendar year 1998, with an increase of only two accidents. Of

ts, 340 were fatal, resulting in a total of 619 fatalities. The number of fatal general aviation accidents in

decrease from calendar year 1998 although the number of resulting fatalities decreased by only 0.8%

cumstances of these accidents and the details related to the aircraft, pilots, and locations involved are

eport.

fety Board is an independent Federal agency dedicated to promoting aviation, railroad, highway, marine, pipeline, and

ablished in 1967, the agency is mandated by Congress through the Independent Safety Board Act of 1974 to investigate

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

ent agencies involved in transportation. The Safety Board makes public its actions and decisions through accident reports,

on reports, safety recommendations, and statistical reviews.

ble in their entirety on the Web at <http://www.ntsb.gov>. Other information about available publications also may be

by contacting:

ion Safety Board

on, RE-51

W.

94

02) 314-6551

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

er PB2003-105847 PB2003-105847 from:

formation Service

22161

03) 605-6000

Act, as codified at 49 U.S.C. Section 1154(b), precludes the admission into evidence or use of Board reports related to an

ion for damages resulting from a matter mentioned in the report.
UCTION ........................................................1

Purpose of the Annual Review..............................................1What Is General Aviation?................................................1Which Operations Are Included in this Review?..................1Which Aircraft Are Included in this Review?.....................1Organization of the Annual Review.........................................2

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

NERAL AVIATION ENVIRONMENT IN 1999.................4

General Economic and Aviation Industry Indicators ............4Fleet Makeup...................................................................5General Aviation Activity....................................................6

ICAL AND CURRENT ACCIDENT DATA......................8

Accident Rates...................................................................8Number of Accidents..........................................................8

N DEPTH .....................................................13

Location of General Aviation Accidents in 1999................13

United States Aircraft Accidents..............................13Foreign Aircraft Accidents....................................14

Aircraft Type...................................................................15Purpose of Flight............................................................15

Flight Plan............................................................16Airport Involvement...............................................17Environmental Conditions.....................................18

Injuries and Damage for 1999.........................................21

Aircraft Damage...................................................21Accident Injuries...................................................21

Injuries by Role for 1999................................................23Accident Pilots................................................................23

Rating..................................................................23Total Time............................................................25Time in Type of Aircraft..........................................26Age..................................................................28

Accident Occurrences for 1999........................................29Phase of Flight................................................................31Most Prevalent Causes/Factors for 1999..........................32

Probable Causes, Factors, and the BroadCause/Factor Classification..................................32Human Performance............................................34

Weather as a Cause/Factor............................................35

GENERAL AVIATION SAFETY ISSUES................................36

Carburetor Icing..............................................................36Fuel Management.............................................................38

ACCIDENTS INVOLVING AMATEUR-BUILT AIRCRAFT..............43

Amateur-Built Aircraft.....................................................43Amateur-Built Aircraft Accident Conditions...........................44Amateur-Built and Manufactured Aircraft Comparison.......45Occurrences..................................................................47Broad Cause/Factor........................................................47Accident Pilots.................................................................49

APPENDIXES

A: Definitions...................................................................53B: The National Transportation Safety BoardInvestigative Process...........................................................54C: The National Transportation Safety BoardAviation Accident/Incident Database...............................55D: National Transportation Safety BoardRegional Offices..............................................................56

CONTENTS
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1

N

Annual Review

sportation Safety Boardís 1999 Annual Review

nt Data for U.S. General Aviation presents a

tion and review of general aviation accidents

1999 involving U.S.-registered aircraft. In

ng accident statistics for 1999, the review also

economic indicators that may have influenced

ctivity for 1999 and contextual accident data

 preceding the reporting period.

a used in this review were extracted from the

ation Accident/Incident Database.1 The activity

eview were extracted from the General Aviation

ty Survey (GAATA Survey)2 and from U.S. Civil

both of which are published by the Federal

ration (FAA), Statistics and Forecast Branch,

ysis Division, Office of Aviation Policy and Plans.

ation was extracted from the General Aviation

sociation (GAMA), General Aviation Statistical

What is General Aviation?General aviation (GA) can be described as any civil aircraftoperation that is not covered under 14 Code of FederalRegulations (CFR) Parts 121, 129, and 135, commonly referredto as commercial air carrier operations.3Which Operations are Included in this Review?This review includes accidents involving U.S.-registered aircraftoperating under 14 CFR Part 91, as well as civilian public use4aircraft operations. Aircraft operating under Part 91 includeaircraft that are flown for recreation and personal transportation,as well as certain aircraft operations that are flown with theintention of generating revenue,5 including business flying, flightinstruction, 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 ofaircraft, including airplanes, rotorcraft, gliders, balloons andblimps, and registered ultralight, experimental, or amateur-builtaircraft.The wide range of operations and aircraft types included withinthe scope of general aviation must be considered wheninterpreting the data presented in this review. For example, the1999 general aviation review includes accidents involving aircraft

 of the Aviation Accident/Incident Database is included in Appendix C.

he GAATA Survey, data associated with air taxi and air tour operations are not included in this review.

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

NTSB/ARC-03-01 (Washington, D.C.: 2003), available at http://www.ntsb.gov.

statutory definition has changed over the years, public aircraft operations are qualified government missions that may include law enforcement, low

al application, firefighting, search and rescue, biological or geological resource management, and aeronautical research.
cident Data 2

pound experimental aircraft to 46,500-

w are any accident data associated with

14 CFR Parts 121, 129, or 135, such

arrier operations, foreign air carrier

d Part 135 air carrier operations

eduled Part 135 air carrier operations

ded are data involving military or non

unless the accident also involves civil

d aircraft, unregistered ultralights, and

es. Crashes involving illegal operations

uded in the accident total, but not in

Annual Review

 is organized into five parts.

summarizes general aviation accident

999, economic and industry markers

neral aviation activity in 1999, and

istics from previous years.

art investigates trends over the past 10

 factors as the types of flight, levels of

ge, and level of injury.

 focuses on accidents that occurred

1999 calendar year and their

 Cause and factor findings for accidents

999 are also listed.

rt discusses selected issues particularly

eral aviation safety. Topics included this

oss of engine power due to carburetor

exhaustion/starvation.

ï The fifth part provides in-depth coverage of a special

topic important to general aviation safety. Becauseof the continued increase in the popularity of amateurbuilt aircraft, the special topic of the 1999 AnnualReview is accidents involving amateur-built aircraft.

Like the 1998 Annual Review, the 1999 Annual Review presentsstatistical data more graphically than in the years prior to 1998.Readers who wish to view the data in a tabular format or whowish to manipulate the data used in the report may access thedata set online at the Safety Boardís Web site, http://www.ntsb.gov.

They may also contact the Safety Boardís Public Inquiries Branchat 202-314-6551.
3

AL AVIATION ACCIDENT SUMMARY

rcraft were involved in 1,906 accidents during

99.6 The total number of general aviation

ng in 1999 was virtually unchanged from

98, with an increase of only two accidents. Of

of accidents, 340 were fatal, resulting in a total

The number of fatal general aviation accidents

ed a 6.6% decrease from calendar year 1998

ber of resulting fatalities decreased by only 0.8%

d. The circumstances of these accidents and

 to the aircraft, pilots, and locations involved

oughout this report.

on between two aircraft is counted as a single accident. The 17 midair collision accidents that occurred in 1999 involved 32 general aviation aircraft

t. In addition, 10 ground collision accidents involved 20 general aviation aircraft.
4

TION ENVIRONMENT IN 1999

d Aviation Industry Indicators

 overview of economic and industry

 for interpreting 1999 general aviation

owing table provides U.S. economic

 of personal income since 1975. The

economic indicators pertaining to the

industrial and personal incomes have

5. The table also shows that, between

 resident population increased by 3.8%,

the gross domestic product rose by 17.4%, and disposablepersonal income rose by 14.2%.Between 1975 and 1995, economic indicators for the generalaviation industry were either steady or declining. Sharp declinesin general aviation aircraft shipments7 during the í70s and í80swere followed by further gradual declines during the early í90s.The total number of new aircraft sold in 1995 was less than 8% ofthe number sold in 1975. Factory billings for new aircraft fluctuatedover the period, with 1995 billings being 2.75 times higher than1975 net billings, primarily because an increase in the value ofturbine aircraft sales compensated for losses in piston aircraft sales.

In contrast to the years between 1975 and1995, which had modest to negativegrowth, general aviation industry indicatorsnearly tripled between 1995 and 1999,resulting from a noticeable increase inshipments after 1994. The percentage ofincrease in net factory billings alonebetween 1995 and 1999 was equal to thetotal increase observed between 1975 and1995. One reason for this rapid growth, inaddition to generally favorable economicconditions, was the increased productionof general aviation aircraft following the1994 passage of the General AviationRevitalization Act8 limiting manufacturer

liability.

abook, 2001.

tion Act, signed into law August 17, 1994, limits the liability of general aviation manufacturers to 18 years.

  	
			 	!

	 
$	 

 
	 
 ' 
	   


!	

' 
	  


 *(%)%+ ( % 	 ,  -

Economic and Aviation Industry Indicators, 1975-1999

. /0. . 0. . 0. 

-'. --/-. -2/. -30. -'-. -/-/

. 4333.43.40//.4'//.4/032.40

	+. 420.42'0.4323/.403-.4002.4'2-3

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30'. //. --. 33. //. -03

*)	+
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 *)	+
. 40/. 4/3. 43. 4-. 4-2. 420

 *)	+
. 43'. 4'. 4-2/. 4'. 4-/. 4/30
5 General Aviation Environment in 1999

 new general aviation aircraft have increased

e last 5 years, most general aviation aircraft

e more than 20 years old. U.S. manufacturers

ew general aviation aircraft in 1999, compared

al of 214,900 general aviation aircraft already

engine piston aircraft have the highest average

of general aviation aircraft and represent the

eet. As a consequence of this fleet makeup,

ated into newly manufactured aircraft may not

 accident record for several years.

Annual Shipments of New U.S.

red General Aviation Aircraft, 1980-1999 

4 1986 1988 1990 1992 1994 1996 1998

ngine Multi-engine Turboprop Jet

Active Aircraft in General Aviation, 1999 

Single-engine piston

150,234 

Balloon

4,603 Amateur-built

16,846

Glider

2,041

Multi-engine piston

19,323 

Turboprop

4,744

Jet

6,624

Rotorcraft

6,702

Category Engine-type Seats Average Age

Single-engine Piston 1-3 28

4 32

5-7 25

8+ 43

Turboprop all 10

Jet all 27

Multi-engine Piston 1-3 21

4 28

5-7 31

8+ 30

Turboprop all 19

Jet all 16

All Aircraft 27

GAMA, General Aviation Statistical Databook, 2000 (1999 Data)
cident Data 6

ivity

s a diverse group of aircraft types and

is diversity, some measure of exposure

rder to make meaningful comparisons

ght activity is typically used to normalize

different groups, with the level of activity

l of exposure to potential accident risk.

rtures, and miles flown are common

re activity.

eduled Part 135 air carriers, which are

ght hours, departures, and miles flown

sportation (DOT) Research and Special

(RSPA),9 operators of general aviation

o report actual flight activity data. As a

up of aircraft must be estimated using

ey.10 The GAATA Survey was established

mation about aircraft use, flight hours,

 installations from owners of general

ed Part 135 aircraft. Because activity

imited sample of aircraft selected from

ers and reporting is not required, activity

n are far less reliable than the data

GAATA Survey, nonscheduled Part 135

om the 1999 Annual Review of General

rdingly, for this review, general aviation

by subtracting those data pertaining to

perations from activity totals whenever

possible. However, in many cases, general aviation activity datacould not be calculated because the survey data represent theaggregate of all aircraft activity, including both general aviationand nonscheduled Part 135 operations. Examples of suchaggregate data include the number of landings, flight hours bystate or region, and flight hours by day/night or weatherconditions.The following graph illustrates the estimated total number ofgeneral aviation flight hours annually for the years 1990 to1999.11 General aviation flight hours began to increase in 1994after a decline during the preceding years. The number of generalaviation flight hours in 1999 was estimated to be 29.7 million, aone-third increase over the 10-year low of 22.2 million hours,estimated in 1994.

ty on a monthly basis, and scheduled Part 135 operators report quarterly.

gov/pubsarchive.asp

ailable at http://www.api.faa.gov/GA2001/tab_1-6.pdf (GA flight hour total excludes air taxi and air tour activity).

General Aviation Flight Hours, 1990-1999

(100,000s)

0

50

100150200250300350

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
General Aviation Environment in 1999 7

tors of general aviation activity are the number

cates issued and the number of active pilots.

w student pilot certificates issued is particularly

use it represents positive growth in the pilot

umber of new student pilot certificates issued12

y each year from 88,586 in 1990 to 56,653 in

 1996 and 1998, the number of new student

sued annually increased slightly to a total of

ped again in 1999 to 58,278.

of active pilots decreased steadily throughout

 í90s, from 702,659 in 1990 to 622,261 in

1997 and 1999, the number of active pilots

n estimated total of 635,472 U.S. pilots active

In summary, the indicators of general aviation activityñflight hoursand the total number of active new and current pilot certificatesissuedñdecreased annually between 1990 and approximately1996. Since then, these indicators have generally begun toincrease. This noticeable change in activity over the period shouldbe considered when attempting to interpret the general aviationaccident record for 1999.

nt Pilot Certificates Issued, 1990-1999

(1,000s)

1992 1993 1994 1995 1996 1997 1998 1999

Estimated Active Pilot Certificates, 1990-1999

(1,000s)

550600650700750

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

n Statistics, available at http://api.hq.faa.gov/CivilAir/docs/air22-99.XLS.

ertificates issued.
cident Data 8

RRENT ACCIDENT DATA

dent rate fluctuated between 1990 and

ts per 100,000 hours flown in 1999,

 lower than the 1994 high of 9.09

hours. Although the accident rate in

rt of a general downward trend since

ate remained fairly constant from 1990

 21% of the total accident rate. The

ccidents per 100,000 flight hours was

r period.

 or number of accident-related deaths

atalities per 100,000 hours flown, the

 period between 1990 and 1999. The

his period occurred in 1992 with 3.5

rs flown.

Because rate calculations require the use of activity dataextrapolated from a relatively small sample of aircraft owners,the resulting values are accurate only to the extent that the samplerepresents the larger population of general aviation operators.For this reason, accident rate data presented in this report willinclude raw frequency data for comparison.Number of AccidentsThere was a slightly downward trend in the number of accidentsthat occurred annually between 1990 and 1997. The number ofgeneral aviation accidents has leveled off or increased slightlysince then, with the number of accidents in 1999 (1,906) beingslightly higher than the 10-year low of 1,845 accidents in 1997.The number of fatal accidents decreased to 340 in 1999, thelowest number for the 10-year period. Fluctuations in accidentfrequency in recent years occurred during a period that also sawchanges in the numbers of new aircraft sales, total general aviationflight hours, and new student pilot starts.

on Accident Rate, 1990-1999

00,000 hours flown

93 1994 1995 1996 1997 1998 1999

idents Fatal Accidents

General Aviation Fatality Rate, 1990-1999

per 100,000 hours flown

2.7

2.9

3.5

3.2 3.3

2.9

2.6 2.5 2.4

2.1

01234

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
9

 of fatalities resulting from general aviation

n 1990 and 1999 reached a high of 867 in

egan a general downward trend to a low of

 observed decline in fatalities is consistent with

evel of activity and the number of fatal accidents

General aviation includes a wide range of operations, each withunique aircraft types, flight profiles, and operating procedures.This diversity is evident in the accident record. Because the flightdata collected in the GAATA Survey allows for only a coarserepresentation of all general aviation operations, the operationsdata presented here include only four operational categories,which were selected as typical of general aviation activity:personal/business flying,14 corporate flying, aerial application,and instructional flights.ï Personal flying makes up the largest portion of general

aviation activity and includes all flying for pleasure and/or personal transportation. Although similar to personalflying, business flying includes the use of an aircraft forbusiness transportation without a paid, professional crew.Personal and business flights are typically conducted in

ral Aviation Accidents, 1990-1999

992 1993 1994 1995 1996 1997 1998 1999

Accidents Fatal Accidents

Fatal General Aviation Accidents and Total

Fatalities, 1990-1999 

0

200400600800

1,000

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

Fatalities Fatal Accidents

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

ng combined exposure data (hours flown).

Historical and Current Accident Data
ccident Data

engine piston airplanes, but may include

aft including gliders, rotorcraft, and

ncludes any business transportation with

ew and usually involves larger, multi

boprop, and jet airplanes.

 includes the use of specially equipped

 and for spraying pesticides, herbicides,

rial application is unique because it

ly close to the ground.

 includes any flight under the supervision

flight instructor.15 Aircraft used for

ts are often similar to those used for

ut instructional operations are unique

 involve the repeated practice of takeoffs

light maneuvers, and emergency

, personal and business flying had the

rate, followed by aerial application and

 accident rate for corporate/executive

tently the lowest overall, averaging less

xt-lowest rate (that is, the rate that was

 flying).

ht instructor certificate and rating requirements.

Accident Rate by Type of Operation, 1990-1999

per 100,000 hours flown

141210

86420

Personal and Business Aerial Application Instructional Corporate

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

10
ccidents by Type of Operation, 1990-1999

ess Aerial Application Instructional Corporate

1992 1993 1994 1995 1996 1997 1998 1999

Historical and Current Accident Data 11

of general aviation accidents involved personal

rations. Between 1990 and 1999, personal/

counted for an average 67% of all general

. Instructional flying has historically accounted

st number, with an average 14% of all general

.

The combined category of personal/business flying also had thehighest fatal accident rate, which was typically more than doublethe rate for any other type of flying. These differences are probablyrelated to the type of aircraft and equipment, the level of pilot training,and the operating environments unique to each type of operation.

Fatal Accident Rate by Type of Operation, 1990-1999

per 100,000 hours flown

43210

Personal and Business Aerial Application Instructional Corporate

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
ccident Data 12

9, personal/business flying accounted

al general aviation accidents and 75%

n injuries. An average 533 fatal injuries

nd 1999 were associated with personal/

d to the average 47 deaths per year

ing.

Number of Fatal Accidents by

Type of Operation, 1990-1999

400300200100

0

350250150

50

Personal and Business Aerial Application Instructional Corporate

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
13

PTH

neral Aviation Accidents in 1999

RAFT ACCIDENTS

the number of general aviation accidents that

state during 1999. The states are also coded, qualitatively signifying (from low to high) the

f accidents. The number of general aviation

g annually in a state is related to the population,

ctivity level, and flying conditions unique to that

e specific hourly activity data needed to calculate

ccident rates for each state were not available

sumptions can be made about general aviation

 on the population of each state. For example,

da,17 and Texas had the greatest number of

9; U.S. Census Bureau data18 indicate that

 highest state population in 1999, followed by

d Florida (fourth). In addition, all three of these

 climates that favor flying year-round, and all

ravel destinations that attract additional general

m other states. These states also had the largest

pilots19 and active aircraft,20 suggesting that the

cidents in these states may be primarily related

activity.

Regional differences that affect general aviation accident numbersmay also include hazards unique to the local terrain and/or weather.For example, Alaska had the fourth-highest number of generalaviation accidents with 114, which was 3.3 times more than NewYork, a state estimated to have a similar number of active aircraftand pilots in 1999.21 However, the operating environment,

infrastructure, and travel requirements in Alaska provide uniquechallenges22 to aviation, and these challenges are reflected in the

general aviation accident record.

Accidents

General Aviation Accidents per State, 1999

140

36

48

47

136

80

59

114

68

182

8

23

28

4

1

10

21

8

25

38 30

25

37

29

13

6

6

35

40

36

10

44 18

42

32

17

43

27

32

31

23

7

11

37

28

18

22

41

41

39

44 to 182 (10 states)37 to 43 (9 states)27 to 36 (11 states)13 to 26 (10 states)

1 to 12 (10 states)

idents for California includes one accident off the coast in the Pacific Ocean.

idents for Florida includes one accident off the coast in the Gulf of Mexico.

; data are available at http://eire.census.gov/popest/archives/state/st-99-1.txt.

en Statistics, 1999, available at http://apo.faa.gov/CivilAir/docs/air5-99.XLS.

1999, available at http://www.api.faa.gov/GA2001/tab_2-3.pdf.

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

only as a demonstration of similar activity.

tion safety in Alaska, see National Transportation Safety Board, Aviation Safety in Alaska, Safety Study, NTSB/SS-95/03 (Washington, DC: 1995). The Safety

 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.
cident Data 14

s the top 15 states by number of general

9, along with the average numbers of

ach of those states over the 10 years

ph illustrates that, except for a noticeable

distribution of accidents was similar to

FOREIGN AIRCRAFT ACCIDENTSU.S.-registered aircraft were involved in 35 accidents in locationsoutside the 50 United States in 1999. These accidents occurredin 15 different countries and territories, and in both the Atlanticand Pacific Oceans. Of those accidents, 14 were fatal, resultingin 33 deaths and 3 serious injuries. The largest number ofaccidents outside the 50 states occurred in Canada, with 7accidents, followed next by the Bahamas with 4. Although mostgeneral aviation accidents involving U.S.-registered aircraftoutside the United States usually occur in neighboring countrieslike Canada and the Caribbean island nations, the 1999 accidentrecord also includes accidents that occurred as far away asGermany, Saudi Arabia, and Thailand.

 Accidents Fatal Accidents FatalitiesPacific Ocean 3 1 2 Off Guam (1) Off Marshall Islands (1)  Off Micronesia (1)Atlantic Ocean 2 1 1 Off Bahamas (2) Other Countries/Territories 30 12 30 Bahamas (4)  Canada (7) Dominican Republic (1) Ethiopia (1) French West Indies (1) Germany (2) Guam (3) Kenya (1) Marshall Islands (1) Mexico (2) Puerto Rico (3) Saudi Arabia/Arabian Gulf (1) Thailand (1) Venezuela (1) Virgin Islands (1)Total 35 14 33

Accidents Involving U.S.-Registered General Aviation Aircraft

Outside the 50 United States, 1999

Aviation Accident States, 1999

100 150 200 250 300

19991989-1997 Average
1999 in Depth 15

phs illustrate the total number of accidents and

 accidents occurring in 1999 by type of aircraft.

e large number of accidents involving single

aft, accounting for 76.8% of all general aviation

5% of all fatal accidents.

Purpose of FlightPurpose of flight can be defined as the reason a flight was initiated.As previously mentioned, general aviation includes a wide rangeof operations, each with unique aircraft types, flight profiles, andoperating procedures. The total number of accidents and the

of Accidents by Aircraft Type, 1999

Balloons

Gliders

Rotorcraft

ne Turbojet

 Turboprop

gine Piston

ngle Piston

All Aircraft

TotalFatal 1

415

31

192

18

61

122

1,463

1,906

34

414

44

233

340

Accident Rate by Aircraft Type, 1999

(per 100,000 hours)

Balloons

Gliders

Rotorcraft

Airplane Turbojet

Airplane Turboprop

Airplane Multi-Engine Piston

Airplane Single Piston

All Aircraft

TotalFatal

9.3

20.0

8.4

0.7

4.5

4.1

7.7

6.4

1.1

1.2

1.5

1.0

0.2

1.5

2.6

0.6

tion accident rate for all aircraft was 6.40

0,000 hours flown, and 1.14 fatal accidents

rs flown. Among fixed-wing powered aircraft,

was highest for single-engine piston aircraft

ts and 1.22 fatal accidents per 100,000 hours

flown. Among all powered aircraft, the accident rate was highestfor rotorcraft, with 8.36 accidents and 1.48 fatal accidents per100,000 hours flown. Glider operations had the highest accidentrate of all aircraft types, with 20.04 accidents and 2.59 fatalaccidents per 100,000 hours flown.
ccident Data 16

y considerably as a result of these

mparisons among different operations,

ed across operations using flight hours

 of flight are derived from the FAAís

 Activity (GAATA) Survey. The GAATA

se/use categories; 2 of these, ìAir Taxiî

ered under 14 CFR Part 135 and are

his review. The remaining 12 categories

mentioned categories of ìpersonal,î

î ìcorporate,î and ìaerial application,î

or more than 85% of general aviation

her, more specific categories, such as

dical use.î A limitation of the activity

es provide only a coarse representation

ght operations. For example, ìpersonal

ot distinguish between travel, recreation,

he same time, the differences between

ersonalî and ìbusiness flyingî are not

ngly, the purpose-of-flight information

 limited to the combined categories of

ng, as well as corporate, instructional,

ghts.

urvey, most general aviation operations

nal and/or business purposes. Of the

ion hours flown in 1999, approximately

conducted for personal or business

evel of activity is that a large percentage

dents involve personal/business flying.

ess flying is actually over-represented

in the accident record considering that this segment includedapproximately half of the activity but accounted for 69% (1,307)of all general aviation accidents and 74% (249) of all fatal generalaviation accidents in 1999.Although personal/business flying has historically had the highestaccident rate, aerial application had a similar accident rate in1999, with 8.78 and 8.69 accidents per 100,000 hours,respectively. Aerial application accidents typically involve contactwith the ground, power lines, or other obstacles that would likelyresult in high levels of occupant injury and damage for mostaircraft. However, the aircraft used in aerial application operationsare often designed with these risks in mind. Aircraft designed foraerial application often include safety features such as ìrollî cagesand 5-point safety harnesses, and pilots often wear helmets. Asa result of these operation-specific factors, aerial applicationaccidents are less likely than other general aviation accidents toresult in fatal injury. Only 10.6% of the aerial applicationaccidents that occurred in 1999 resulted in fatalities, comparedto 19.1% of personal/business flying accidents. When comparedwith the number of hours flown, the fatal accident rate for aerialapplication operations is 0.92 fatal accidents per 100,000 hoursflown. The fatal accident rate remains highest for personal andbusiness flying, with 1.67 fatal accidents per 100,000 hours flown.FLIGHT PLAN

Of the 1,933 pilots involved in accidents in 1999, 1,602 (82.9%)did not file a flight plan. In most cases, a flight plan is requiredonly for flight under instrument flight rules (IFR); however, pilotsoperating under visual flight rules (VFR) on point-to-point flightscan also file a flight plan to aid search and rescue efforts if theyfail to arrive at their intended destination.

ailable at http://apo.faa.gov/GA2001/tab_1-6.pdf.
1999 in Depth 17

MENT

t aircraft locations were closely split between

way from an airport (50.2%) and those occurring

rstrip (46.4% combined); however, it is difficult

ent risk based on location because of exposure

ents that occur on or near an airport or airstrip

rcraft at relatively low altitudes and airspeeds

, landing, or maneuvering to land. Accidents

rom an airport typically include aircraft in the

neuvering, and descent phases of flight. They

her altitudes and higher airspeeds than aircraft

e vicinity of an airport. Because of these

ents that occur away from an airport are more

igher levels of injury and aircraft damage. As

hows, most aircraft involved in fatal accidents

ated away from an airport or airstrip.

Another distinction in flight profiles is between local and pointto-point flights. A local flight is one that departs and lands at thesame airport, and a point-to-point flight is one that lands at anairport other than the one from which it departed. Local flightsinclude sightseeing, flight instruction, proficiency, and pleasureflights, as well as many aerial observation and aerial applicationflights. Conversely, point-to-point flights include any operationwith the goal of moving people, cargo, or equipment from oneplace to another. Examples include corporate executivetransportation, personal and business travel, and aircraftrepositioning flights.

Plan Filed by Accident Pilot, 1999 

IFR

7.1% 

VFR

9.1% 

Unknown

0.8%

VFR/IFR

0.1%

Airport Involvement, 1999

27

260

60

66

970

897

Unknown

Off Airport

On Airport/Airstrip

Accident AircraftFatal Accident Aircraft
cident Data 18

cts a comparison of accident aircraft on

int-to-point flights. As the graph shows,

t on each type of flight were similar, with

unting for slightly more accident aircraft.

ry to compare local and point-to-point

vailable. However, a comparison of the

point-to-point accident flights conducted

ght provides an indirect measure of the

n both flight profiles. The following graph

business flights (64%) were point-to-point,

flights (68.5%) were local. Corporate

d aerial application operations were also

th 100% of corporate flights being point

erial application flights being local.

ENVIRONMENTAL CONDITIONSMany hazards to safety are unique to the type of flight operation,type of aircraft, and flight profile, but environmental conditions maybe hazardous to all flight operations and all types of aircraft to somedegree. Aircraft control is highly dependant on visual cues relatedto speed, distance, orientation, and altitude. When visual informationis degraded or obliterated because of clouds, fog, haze, orprecipitation, pilots must rely on aircraft instruments to provide thenecessary information. Because of the difficulties associated withflying an aircraft solely by reference to instruments, the FAA hasestablished specific pilot, aircraft, and procedural requirements24for flight in instrument meteorological conditions (IMC).

Local and Point-to-Point Flight Comparison

by Type of Operation, 1999 

4.1%

100.0%

31.5%

64.0%

95.9%

0.0%

68.5%

36.0%

Aerial Application

Corporate/Executive

Flight Instruction

Personal/Business

LocalPoint-to-Point

oint-to-Point Flights, 1999

Point-to-Point

53.7%

4 1,038

67-193, 91.205(d).
1999 in Depth 19

 FAA Pilot/Controller Glossary, ìinstrument

onditionsî are defined as ìMeteorological

sed in terms of visibility, distance from cloud,

 than the minima25 specified for Visual

onditions (VMC).î Weather minima differ based

ce, and lighting conditions, but 3 statute miles

oud clearance of 1,000 feet above, 500 feet

feet horizontal distance is typical. The following

e percentage of accidents and fatal accidents

MC and IMC. Although instrument conditions

.6% of all accidents, 17.1% of fatal accidents

Considering the percentage of accidents in each weathercondition that resulted in a fatality illustrates the hazards associatedwith flight in IMC. Only 14.9% of accidents in visual conditionsresulted in a fatality, but 54.7% of accidents in instrumentconditions were fatal. One reason for the disproportionatenumber of fatal accidents in IMC is that accidents that occurduring instrument flight are more likely to involve pilotdisorientation, loss of control, and collision with terrain orobjectsóaccident profiles that typically result in high levels ofdamage and injury. Instrument conditions may also contributeto accident severity by further complicating situations that mightbe more easily handled in visual conditions. For example, a forcedlanding due to an engine malfunction or failure, which mightresult in minor damage if it were to occur in visual conditions,might pose an even greater threat to a pilot flying in instrument

eteorological conditions are specified in 14 CFR 91.155.

dent Weather Conditions, 1999 

Unknown

1.4%

IMC

5.6%

Fatal Accident Weather Conditions, 1999 

IMC

17.1%

Unknown

5.0%

VMC

77.9%
cident Data 20

ced visibility would make the selection

ation more difficult.

esent a similar hazard to pilots because

ated to night vision, difficulties in seeing

as mountains, terrain, and unlighted

ual illusions associated with having fewer

sented in the following graphs illustrate

 accidents occur in daylight conditions

f the accidents that occur at night result

In fact, the following chart shows that accidents that occur atnight are twice as likely as daylight accidents to be fatal. Likeweather-related accidents, accidents at night are more likely toinvolve disorientation, loss of control, and/or collision with objectsor terrain that result in higher levels of injury. The reduction invisual cues at night also hinders pilots from identifyingdeteriorating weather conditions and further complicates anyaircraft equipment malfunctions.

atal and Non-Fatal Accidents

nstrument Meteorological

nditions, 1999 

45.3%

54.7%

)

IMC

(106 accidents)

n-Fatal Fatal

Lighting Conditions of All Accidents and

Fatal Accidents, 1999 

16

2

265

11

46

34

18

1,651

59

144

Not Reported

Dawn

Day

Dusk

Night

All AccidentsFatal Accidents
1999 in Depth 21

amage for 1999

estigators record aircraft damage as either

stantial,î or ìminor.î ìSubstantial damageî is

 830.2 as ìdamage or failure which adversely

al strength, performance, or flight characteristics

 which would normally require major repair or

he affected component.î ìDestroyedî and

pecifically defined in 49 CFR 830.2; however,

e defined as any damage in which repair cost

 value of the aircraft,26 and ìminorî damage

hat is not classified as either ìdestroyedî or

Most aircraft involved in accidents during 1999 sustainedsubstantial damage (77.9%), and approximately one in fiveaccident aircraft (20.7%) were destroyed. ìMinorî and ìnodamageî classifications included less than 1% each of accidentaircraft.ACCIDENT INJURIES

Safety Board investigators categorize injuries resulting fromgeneral aviation accidents as ìfatal,î ìserious,î or ìminor.î Title49 CFR 830.2 defines a fatal injury as ìany injury which resultsin death within 30 days of the accident.î Title 49 CFR 830.2also outlines several qualifications27 of serious injury that include,but are not limited to, hospitalization for more than 48 hours,

f Accidents Resulting in a Fatality

y Lighting Condition, 1999 

16.1% 18.6%

31.9%

Day Dusk Night

able aircraft are also considered ìdestroyed.î

he complete definition of injury categories.

Aircraft Damage, 1999

Substantial

77.9%

Minor

0.8%

Destroyed

20.7%

None

0.6%
cident Data 22

an damage, or second- or third-degree

aph depicts the percentage of general

ng in each level of injury during 1999.

that more than half (54%) of general

 result in injury.

rate both the number of accident aircraft

d the corresponding number of persons

o sustained injuries in each category.

al to the highest level of injury sustained

rcraft. Again, most persons who were

aircraft that were involved in accidents

ury per Accident Aircraft, 1999

Serious

10.4%

Fatal

17.7%

Minor

16.9%

Number of Accident Aircraft by

Highest Level of Injury, 1999 

340

196

323

1,047

0

500

1,0001,5002,000

Fatal Serious Minor None

Injuries Sustained by Persons

Aboard Accident Aircraft, 1999

619

322

605

1,986

0

500

1,0001,5002,000

Fatal Serious Minor None
1999 in Depth 23

e for 1999

ble presents detailed information

f injuries incurred by all persons

al aviation accidents in 1999. The

eral aviation accident injuries varies

operation and the size of aircraft,

f injuries experienced by any group

s with their exposure risk. For

aft have a pilot, but not all aircraft

n board. In 1999, 575 passengers

vel of injury in general aviation

red to the 804 pilots who were

he apparent difference, the injury

ers was similar to that of pilots,

nly 1,262 of 1,933 accident aircraft

n board. As noted previously, most

accidents involve personal/business flights in

on aircraft, which are likely to have only one

 this exposure difference, pilots sustained the

e of injuries in general aviation accidents in

.2% of all fatalities, 58.1% of all serious injuries,

minor injuries.

ies sustained by persons on board the accident

ns who were not aboard accident aircraft also

 Examples of accidents in 1999 that resulted

ons not aboard an aircraft include a ground

killed after contact with an aircraft propeller

seriously injured when an airplane struck their

Accident PilotsRATINGOf the 1,933 pilots involved in general aviation accidents in 1999,the largest percentage (43.8%) held a private pilot certificate.28The second-largest percentage (37.0%) held a commercial pilotcertificate, which is required in order for any person to act as pilotin-command of an aircraft for compensation or hire.29

n Statistics, available at http://api.hq.faa.gov/CivilAir/index.htm.

 for the privileges granted by a commercial pilot certificate.

Personal Injuries Fatal Serious Minor None Total

Pilot 317 187 300 1,129 1,933

 Copilot 21 12 14 70 117 Flight Engineer 1 0 0 1 2 Flight Instructor 1 0 0 0 1 Dual Student 15 6 18 80 119 Check Pilot 1 1 0 4 6 Other Crew 10 8 2 13 33 Flight Attendant 0 0 0 2 2 Passenger 249 103 223 687 1,262 Total Aboard 615 317 557 1,986 3,475 On Ground 3 5 48 0 56 Other Aircraft 1 0 0 0 1 Total 619 322 605 1,986
ccident Data 24

umber of active pilots in 1999 holding

ate, commercial pilot certificate holders

general aviation accidents. The 21.1%

mercial pilot certificates accounted for

As depicted in the following graph, the accident rate per 1,000active pilots was highest for commercial pilot certificate holders,who can be employed as pilots and are likely to fly more hoursannually than student or private pilots. Annual flight-hour data forpilots holding each type of certificate are not available to confirm

this conclusion. The U.S. Civil Airmen Statistics compiled by theFAA30 also do not include information about the type of operation

that certificate holders engage in, but examples of commercialoperations include corporate executive transportation, flightinstruction, sightseeing flights, banner towing, and aerialapplication. The largest percentage of commercial pilots involvedin accidents during 1999 (42.3%) were conducting personal flights

e Held by Accident Pilot, 1999

















 




Active Pilots by Highest Certificate, 1999 

Private

42.0%

Commercial

21.1% Airline Transport

21.6% 

Recreational

0.1%

Student 

15.2% 

, 1999, available online at http://api.hq.faa.gov/CivilAir/index.htm.

G, for the privileges and limitations of the airline transport pilot certificate.
1999 in Depth 25

lved in a commercial operation at the time of

ine transport pilot (ATP) certificate holders, in

employed as pilots,31 can engage in air carrier

h are not included in this review. As a result, ATP

may fly fewer general aviation hours and have

viation accident rate.

cidents in 1999 for which pilot total flight

re available, 47.9% involved pilots with fewer

 of flight time. The following chart depicts the

erience among accident pilots; the inset focuses

with fewer than 1,000 hours. The largest

cident pilots in this group had between 100

and 200 hours of total flight time, and a total of 446 pilots had300 hours or fewer. When compared to all accident pilots withavailable data, approximately 24% of accident pilots had 300hours of flight experience or fewer.Because of the minimum hour requirements33 for obtainingcommercial and airline transport pilot certificates, it is notsurprising that most accident pilots with 300 or fewer total hoursof flight time held either private pilot certificates (69.6%), or studentpilot certificates (27.0%). Most pilots with more than 1,000 totalhours of flight time held commercial pilot certificates (55.8%),followed next by those with ATP certificates, and then by thosewith private pilot certificates.

 Rate per 1,000 Active Pilots, 1999

Private Commercial ATP

3.10

5.21

1.60

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.

Accident Pilot Total Time, 1999

>10,000

Flight Hours

0-1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000

897

287

139

95 85 54 34 40 18 28

197

0

50

100150200

0-100 200 300 400 500 600 700 800 900 1,000

163 170

113 102

78

59 58 45 58 51
cident Data 26

t most accident pilots with 300 or fewer

re flying single-engine piston airplanes

ed. Accident pilots with more than 1,000

 diverse selection of aircraft, including

-engine airplanes, 5.6% who were flying

13.8% who were flying helicopters.

Time in Type of AircraftOf the 1,647 accidents in 1999 for which data are availableabout pilot experience in the accident aircraft make and model,85.5% involved pilots with 1,000 or fewer hours of time in theaccident aircraft make and model. The inset chart below depictsthe distribution of experience among those accident pilots with

Aircraft Type Flown by Pilots with Fewer

Than 300 Hours Total Flight Time, 1999

1.6%1.6%

4.7%

0.0%0.0%

1.1%

89.7%

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, 1999 

0.6%

2.1%

13.8%

2.1%

5.6%

9.2%

65.9%

Balloon

Glider

Rotorcraft

Airplane Turbojet

Airplane Turboprop

Airplane Multi-engine Piston

Airplane Single-engine Piston

te Held by Accident Pilots

00 Hours Total Flight Time, 1999

Student

27.0%

None

0.7%

Commercial

2.8%

te Held by Accident Pilots

00 Hours Total Flight Time, 1999

Airline Transport

22.3% 

Student

0.4%

Private

21.4%
1999 in Depth 27

0 hours in type. The largest percentage of

this group (50.8%) had fewer than 100 hours

n the accident aircraft type, and a total of 103

 accident pilots for whom data are available)

0 hours in type. Most accident pilots with fewer

ight time in make and model were flying single

raft.

w time in type because they are new pilots with

ey are experienced pilots who are transitioning

Two types of pilots who might be expected to

 significant time in make and model are those

n airplanes and fly them often and professional

ame aircraft often. A large number of general

ho own aircraft have single-engine piston

ters and multi-engine piston, jet, and turboprop

e likely to be operated by professional pilots.

The percentage of accident pilots with low time in make andmodel who were flying gliders is also worth noting and is probablydue to the shorter durations typical of glider flights compared tothose of powered aircraft. Comparison of the two graphs showsthat pilots with more than 100 hours in make and model weremore likely than pilots with fewer hours in type to be flyingrotorcraft or multi-engine piston, jet, or turboprop airplanes.

nt Pilot Time in Aircraft Type, 1999

21 17 78 44 3 10

4,000 5,000 6,000 7,000 8,000 9,000 10,000 >10,000

Flight Hours

45 45 36 30 86 65 108

248

709

103

36

0

100200300400500600700800

0-10 0-100 200 300 400 500 600 700 800 900 1,000

Aircraft Type Flown by Pilots with Fewer Than

10 Hours Flight Time in Make/Model, 1999 

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, 1999

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
cident Data 28

Accident pilots conducting flight instruction operations, whichinclude both student pilots and flight instructors, had the lowestaverage age of all pilots. Accident pilots conducting personal/business flights had the highest average age at 50.4 years.

cs, 1999, available at http://apo.faa.gov/CivilAir/docs/air13-99.xls.

Accident Pilots, 1999

0-39 40-49 50-59 60-69 70+ Unknown

Age in Years

strates the age distribution of pilots

ring 1999. Most accident pilots were

and 59. The average age of all active

n increasing steadily over the last decade

years in 1999, while the average age of

 pilots was 48.1 years. No meaningful

regarding specific age-related accident

ur activity numbers are not available for

likely that opportunities for recreational

ge.

Average Age of Active Pilots, 1990-1999

40.5 40.5 40.8 41.3 41.9 42.9 43.2 43.6 43.6 43.6

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

Average Age of Accident Pilot by Type of

Operation, 1999 

50.4

48.5

44.5

40.7

Personal/Business

Corporate/Executive

Aerial Application

Flight Instruction
1999 in Depth 29

rences for 1999

s of an accident are documented in the Safety

eport as accident ìoccurrencesî and ìsequence

 occurrence data can be defined as what

the accident. A total of 5435 occurrence codes

describe the events for any given accident.

accidents are rarely limited to a single event,

coded as a sequence (that is, occurrence 1,

.), with as many as five different occurrence

nts that involve more than one aircraft, the list

ay be unique to each aircraft. Of the 1,896

n 1999 with data available, 1,422 had 2 or

, 664 had 3 or more, 86 had 4 or more, and

5 occurrences (each) coded in the accident

ts. Each accident event includes information

ial order of its occurrence. For example, one

nvolved an airplane that experienced a loss of

a result of the engine failure, the aircraft made

scent and forced landing. During the landing

contacted vegetation and the landing gear

 of these occurrences was coded; the first

xample, was coded ìloss of engine power

e.î An excerpt from the brief report for this

ed here as an example of how occurrences are

Occurrence data do not include any information about why anaccident may have happened; the first occurrence can insteadbe considered the first observable link in the accident chain ofevents. The following table displays the first occurrences for allof the 1999 general aviation accident aircraft with sequence ofevents data available. To simplify the presentation of accidentoccurrence data, similar occurrences have been grouped intoeight major categories.

Occurrence #1: LOSS OF ENGINE POWER (TOTAL) - MECH FAILURE/MALF

Phase of Operation: CRUISEFindings 1. (C) FUEL SYSTEM, CARBURETOR - EXCESSIVE FLOW/OUTPUT2. (C) MAINTENANCE, INSTALLATION - IMPROPER - UNKNOWN

---------- Occurrence #2: FORCED LANDINGPhase of Operation: EMERGENCY DESCENT/LANDING---------- Occurrence #3: ON GROUND/WATER ENCOUNTER WITH TERRAIN/WATER

Phase of Operation: LANDING - ROLLFindings 3. TERRAIN CONDITION - HIGH VEGETATION4. GROUND LOOP/SWERVE - ENCOUNTERED - PILOT IN COMMAND

---------- Occurrence #4: GEAR COLLAPSEDPhase of Operation: LANDING - ROLLFindings 5. LANDING GEAR - OVERLOADFindings Legend: (C) = Cause, (F) = FactorThe National Transportation Safety Board determines the probable cause(s) of this accident as follows. An improperly installed and maintained float needle in the carburetor, which would not seat sufficiently to stop fuel flow and caused the engine to run excessively rich, resulting in a complete loss of engine power. 

missing aircraftî and ìundetermined,î do not represent operational events.
ccident Data 30

1999 Accident First Occurrences

Total Fatal Total Fatal

308 109 Power Related 505 48

n Flight Collision With Object 151 48 Loss of Engine Power 190 20

t Collision with Terrain/Water 106 46 Loss of Engine Power (Total) - Nonmechanical 156 12

Midair Collision 31 15 Loss of Engine Power (Total) - Mech Failure/Malfunction 77 5

Undershoot 20 0 Loss of Engine Power (Partial) - Mech Failure/Malfunction 35 5

ear Collision Between Aircraft 0 0 Loss of Engine Power (Partial) - Nonmechanical 34 3

447 155 Rotor Failure/Malfunction 2 1

Loss of Control - In Flight 252 104 Propeller Failure/Malfunction 10 2

t/System Failure/Malfunction 104 20 Engine Tearaway 1 0

ight Encounter with Weather 77 29 Landing Gear 51 0

Abrupt Maneuver 3 2 Wheels Up Landing 17 0

Forced Landing 8 0 Gear Collapsed 19 0

rtex Turbulence Encountered 2 0 Main Gear Collapsed 10 0

tude Deviation, Uncontrolled 1 0 Gear Retraction on Ground 0 0

Decompression 0 0 Nose Gear Collapsed 3 0

ter 108 3 Complete Gear Collapsed 0 0

d/Water Collision with Object 51 0 Wheels Down Landing in Water 1 0

Encounter with Terrain/Water 35 2 Tail Gear Collapsed 1 0

n Aircraft (Other than Midair) 14 0 Other Gear Collapsed 0 0

Rotor, Pod, Float, or Tail/Skid 8 1 Gear Not Extended 0 0

r Water 442 5 Gear Not Retracted 0 0

Loss of Control - On Ground 238 1 Miscellaneous 32 5

Hard Landing 120 1 Miscellaneous/Other 21 3

Overrun 45 1 Fire 8 1

Nose Over 15 0 Explosion 1 0

Roll Over 5 0 Fire/Explosion 2 1

eller/Rotor Contact to Person 2 2 Hazardous Materials Leak/Spill 0 0

und Encounter with Weather 14 0 Cargo Shift 0 0

Nose Down 3 0 Undetermined 3 3

 Blast or Jet Exhaust/Suction 0 0 Missing Aircraft 2 2

Ditching 0 0 Undetermined 1 1
1999 in Depth 31

major categories of first occurrences, the largest

s (26.6%) included occurrences related to aircraft

he individual occurrences, the most common

control either in flight (13.3%) or on the ground

ugh loss-of-aircraft-control-on-the-ground

ed in only 1 fatal accident, loss-of-control-in

resulted in a total of 104 fatal accidents, which

rd of all fatal accidents and more than twice as

her single occurrence.

ation displays the percentage of accident aircraft

ght at the time of first occurrence. The phase of

ed as when, during the operation of the aircraft,

e took place. There are 50 distinct phases of

gators may use to describe the operational

currences. To simplify the presentation of this

etailed phases have been grouped into eight

gories for this illustration. For example, the

chî includes any segment of an instrument

ion in the airport traffic pattern and continues

anding on the runway. The upper set of numbers

centage of all accidents that occurred in each

mbers in parentheses indicate fatal accidents.

he illustration, most

d during landing and

the relatively short

hases in comparison

e of a normal flight.

r of accidents that

keoff and landing

sed workload placed

crew and the aircraft

ses. During takeoff

and landing, the flight crew must control the aircraft whilechanging altitude and speed, communicating with air trafficcontrol (ATC) and/or other aircraft, and maintaining separationfrom obstacles and other aircraft. Aircraft systems are alsostressed during takeoff and landing with changes in engine powersettings, the possible operation of retractable landing gear,flaps, slats, and spoilers, and changes in cabin pressurization.While the aircraft is at low altitude during takeoff and landing,it is also most susceptible to any hazards caused by wind andweather conditions.Notably, the largest percentage of total accident first occurrences(28.6%) happened during the landing phase of flight, but only3.5% of fatal accident first occurrences happened during thisphase. The largest percentage of fatal accident first occurrences(29.1%) occurred during the maneuvering phase of flight, butonly 13.6% of all accident first occurrences occurred during thisphase. These statistics reflect the relative severity of the types ofaccidents that are likely to occur during each of these phases.Accidents during cruise and maneuvering are more likely toresult in higher levels of injury and aircraft damage due to thehigher speeds and altitudes associated with these phases offlight.

Standing/Taxi/Other Takeoff Climb Cruise Descent Manuevering Approach Go-Around Landing

3.7% 20.4% 4.0% 14.2% 3.2% 13.6% 10.1% 2.1% 28.6%

( 0.9% ) ( 18.0% ) ( 6.6% ) ( 20.6% ) ( 4.4% ) ( 29.1% ) ( 14.6% ) ( 2.2% ) ( 3.5% )

Accident Aircraft Phase of Flight During First Occurrence, 1999

1,877 Accident Aircraft with Phase of Flight Data in 1999
ccident Data 32

craft accident first occurrence during

s with different aircraft types and types

single-engine piston aircraft used for

re takeoffs and landings because new

e skills. As a result, 43.2% of all first

cidents involving single-engine aircraft

ccurred during the landing phase and

g takeoff. In contrast, the largest

ences for accidents involving helicopter

euvering or hovering (37.4%), reflecting

licopter operations.

es/Factors for 1999

 FINDINGS, AND THE BROAD CAUSE/FACTOR

ccident occurrences, the Safety Board

of probable cause. The objective of

cern the cause-and-effect relationships

. This could be described as why the

 determining probable cause of an

rd considers all facts, conditions, and

h accident occurrence, any information

planation of that event is identified as

further designated as either a ìcauseî

actorî is used to describe situations or

buted to the accident cause. The details

oded as the combination of all causes,

sociated with the accident. Just as

 series of events, the reason why those

t may be the combination of multiple

 this reason, a single accident report

se and factor codes.

ent are included here as an example.

began when a single-engine airplane

lost electrical power in flight due to an alternator failure. Becausethe retractable landing gear on the aircraft relied on anelectrically driven hydraulic pump, the gear would notautomatically extend and the pilot attempted to lower the gearmanually. The pilot did not follow the recommended procedurefor alternate gear extension, and the landing gear failed to fullyextend. Because it was not fully extended, the gear collapsedduring landing and the aircraft sustained substantial damage.In the findings of this accident, the pilotís failure to follow theproper gear extension procedures was cited as a cause, andboth the alternator failure and the failure of the landing gear tofully extend were cited as factors. An excerpt of the brief for thataccident is included as an example of how those findings wererecorded.To simplify the presentation of probable cause information, thehundreds of unique codes have been grouped into broad cause/factor categories. This broad cause/factor classification providesan overview of fundamental accident origins by dividing allaccident causes and factors into three groups: aircraft,environment, and personnel. The following graph depicts thenumber of general aviation accidents that fall into each broadcause/factor classification. Personnel-related causes or factorswere cited in 89.8% of all general aviation accident reports for

Occurrence #1: AIRFRAME/COMPONENT/SYSTEM FAILURE/MALFUNCTIONPhase of Operation: CRUISEFindings 1. (F) ELECTRICAL SYSTEM,ALTERNATOR -FAILURE,TOTAL---------- Occurrence #2: FORCED LANDINGPhase of Operation: EMERGENCY DESCENT/LANDINGFindings 2. (F) LANDING GEAR - OTHER3. (C) PROCEDURES/DIRECTIVES NOT FOLLOWEDPILOT IN COMMANDFindings Legend: (C) = Cause, (F) = FactorThe National Transportation Safety Board determines the probable cause(s) of this accident as follows.The pilot’s failure to follow alternate landing gear extens ion procedures. Factors were the main landing gear failure to extend and a loss of electrical power.
33 1999 in Depth

ause/factor data were available (N=1,864).

auses/factors were cited in 40.8% of these

and aircraft-related causes/factors were cited

ts.36 Environmental conditions are rarely cited

ause but are more likely to be cited as a

r. In 1999, only 62 of 760 environmental

 all environmental cause/factors) were listed

he remainder listed as contributing factors.

aph displays the cause/factors of the 1999

ailable information. As mentioned previously,

nique codes are available to document causes/

 this graph summarizes those codes by the

 factor categories of personnel, environment,

by the next-lower-level subcategory.

The preceding graph clearly shows that most causes and factorsattributed to general aviation accidents are personnel related.The pilot is the most frequently cited individual in the personnelcategory; however, other persons not aboard the aircraft arecited as a cause or factor in 166 accidents. Examples of accidentrelated personnel not aboard the aircraft could include an airtraffic controller, a maintenance technician, or airport personnel.In the broad category of environmental factors, weather conditionswere cited in a total of 358 (19.2%) accidents. Powerplantrelated37 causes/factors were the most commonly cited factorswithin the broad category of aircraft and were cited in 262 (14.1%)

of the general aviation accidents in 1999.

oard frequently cites multiple causes and factors for an aircraft accident, the number of causes and factors will result in a sum greater than the total

ionî 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

 propulsion, while ìengine power lossî refers only to the total loss of engine power.

Accident Cause/Factors, 1999

127

477

33

41

45

80

156

262

568

55

77

182

331

358

760

9

20

166

1,559

1,674

Undetermined

 Engine Power Loss

 Aircraft Performance

 Instruments

 Flight Control Systems

 Systems and Equipment

 Aircraft Structure

 Landing Gear

 Fluid

 Powerplant/Propulsion

All Aircraft Related

Airport/Airways Facilities, Aids

 Light Condition

 Object

 Terrain Condition

 Weather Condition

All Environment Related

 Organizations

 Others (aboard)

 Others (not aboard)

 Pilot

All Personnel Related

1,864 Accidents with Findings in 1999

e/Factors and Causes of General 

Aviation Accidents, 1999

(1,864 accidents with findings)

760

1,674

62

1,629

Environment Personnel

ause or Factor Cause only
cident Data 34

ws that specific accident causes and

erent types of flight operations. For

 and factors were cited in 41.8% of

dents, compared to only 30.4% of

8.4% of flight instruction accidents. The

aft cause/factors for aerial application

 the flight profile of aerial application

hey operate at low altitudes, pilots

cation operations have less time and

ng with mechanical difficulties. Any

may therefore be more likely to lead to

and factors were cited in 59.8% of

 application operations, compared to

ctively, for personal/business and flight

Because of the low altitudes typical of

ons, environmental factors like terrain

reater hazard than to other types of

volve landing on unsuitable terrain are

ause pilots have fewer options in the

. Support for these suggestions comes

e/Factor of Accidents by

of Operation, 1999

9.8%

87.7%

41.4%

89.7%

35.6%

92.1%

Environment Personnel

Personal/Business Flight Instruction

from the fact that terrain conditions and objects account for77% of all environmental causes/factors cited in aerialapplication accidents.Flight instruction accidents were presumably less likely to citeenvironmental causes and factors because solo student pilotsand flight instructors chose not to fly in marginal weatherconditions, but were more likely to cite personnel cause/factorsdue to an increase in aircraft control and decision-making errorsassociated with individuals learning to fly.HUMAN PERFORMANCEThe information recorded in the personnel category refers primarilyto whose actions were a cause or factor in an accident. Toincrease the level of detail about the actions or behavior thatmay have led to an accident, causal data related to humanperformance issues and any underlying explanatory factors arealso recorded. The information in these categories can be thoughtof as how and why human performance contributed to the accident.For example, if a pilot became disoriented and lost control of anaircraft after continuing a visual flight into instrument flightconditions, the pilot would be cited as ìcauseî in the personnelcategory, and planning/decision-making would likely also becited in the human performance issues category.Of the 1,549 accidents for which the cause or factor was attributedto human performance, the most frequently cited cause/factorwas aircraft handling and control (64.3%), followed by planningand decision-making (38.8%) and use of aircraft equipment(11.4%). Issues related to personnel qualification were cited in42.4% of the 224 accidents with underlying explanatory factorsrelated to human performance. Examples of qualification issuesthat were cited in the 1999 accident record include lack ofexperience, improper training, and lack of certification.
1999 In Depth 35

Cause/Factor

aviation aircraft are often smaller, slower, and

m altitude and range in comparison to transport

hey can be more vulnerable than larger aircraft

by weather. Smaller aircraft are affected to a

adverse wind conditions, and precipitation, icing,

ather have a greater effect on aircraft that lack

e, and/or range capabilities to avoid those

er conditions cited most often as a cause or

viation accidents are related to winds, including

,î and ìtailwind.î Of the top five causes/factors

iation accidents in 1999, three were related to

craft are most susceptible to the effects of wind

d landings, the effect of adverse wind is reflected

ntage of general aviation accidents that occur

es of flight.

Just as most landing accidents do not result in fatal injuries, mostwind-related accidents are also not fatal. The wind-related weatherfactors ìcrosswind,î ìgusts,î and ìtailwindî were cited as a cause/factor in a total of 198 accidents, but only 5 of those accidentswere fatal. Among fatal general aviation accidents, four of thefive most frequently cited weather factors were related to conditionsthat resulted in reduced visibility, including ìlow ceiling,î ìfog,îand ìclouds.î Accidents under conditions of low visibility mayinclude pilot disorientation, loss of control, or collision withobscured obstacles or terrain, all of which are likely to result insevere injuries and aircraft damage.

Cause / Factor Cause

 issues 1,549 1,497

ntrol 996 943

601 526

ment 177 151

115 92

ormation/ATC 69 51

ce 14 8

3 2

0 0

ory factors 224 55

95 5

on 52 20

tion 48 9

nadequate 12 5

11 10

9 1

6 1

ate 6 4

1 1

Total 358 Total 66 Crosswind 78 Low Ceiling 23 Gusts 74 Clouds 11 High Density Altitude 48 Fog 9 Tailwind 46 High Density Altitude 9 Low Ceiling 34 Obscuration 8 Downdraft 23 Icing Conditions 6 Carburetor Icing Conditions 18 Thunderstorm 6 Clouds 16 Rain 5 Fog 16 Turbulence 4 Icing Conditions 13 Drizzle/Mist 3 Turbulence 13 Downdraft 2 High Wind 12 Gusts 2 Sudden Windshift 12 Snow 2 Obscuration 10 Tailwind 2 Dust Devil/Whirlwind 9 Below Approach/Landing Minimums 1 Rain 9 Crosswind 1 Variable Wind 9 Hail 1 Windshear 8 High Wind 1 Snow 7 Lightning 1 Thunderstorm 7 Mountain Wave 1 Unfavorable Wind 6 Turbulence in Clouds 1 No Thermal Lift 5 Turbulence, Terrain Induced 1 Drizzle/Mist 3 Variable Wind 1 Below Approach/Landing Minimums 2 Carburetor Icing Conditions 0 Temperature 2 Dust Devil/Whirlwind 0 Hail 1 Haze/Smoke 0 Haze/Smoke 1 Microburst/Dry 0 Lightning 1 No Thermal Lift 0 Microburst/Dry 1 Sudden Windshift 0 Mountain Wave 1 Temperature, High 0 Turbulence in Clouds 1 Unfavorable Wind 0 Turbulence, Terrain Induced 1 Updraft 0 Updraft 1 Whiteout 0 Whiteout 1 Windshear 0

All Accidents Fatal Accidents

Weather as a Cause/Factor, 1999

Note: due to the possibility of multiple findings, the sum of cause/factors is greater than the accident total.
cident Data 36

 SAFETY ISSUES

usses several issues particularly relevant

y. This section is not meant to be an

l safety concerns, but rather a sample of

eral aviation. Because of the high number

ch year involving a partial or total loss of

power-related problems, carburetor icing

been selected for discussion.

anes accounted for approximately 70%

et in 1999. Many of these single-engine

ny piston helicopters, use a carbureted

of fuel system, a carburetor is used to

and fuel into the engine. Intake air is

 through a venturi, or narrow passage,

venturi is designed to create a low

ir flows through the passage. The low

 through a jet located in the passage,

 intake air, and then drawn through the

engine for combustion.

The combination of the adiabatic expansion of air as it flowsthrough the carburetor, and the vaporization of fuel, causes asudden cooling of the fuel/air mixture. Any water vapor in theair, or water suspended in the fuel, may condense as a result ofthis cooling. If the temperature inside the carburetor is at orbelow freezing, condensed water vapor may form ice inside thecarburetor. Even a slight accumulation of carburetor ice canreduce power, and may eventually lead to a complete enginefailure if the accumulation continues. Some carburetor designsand fuel types, such as automotive gasoline, are more likely toencounter carburetor icing than others, but all carbureted enginesare susceptible.Because the inside of the carburetor is much colder than theambient air temperature, carburetor icing is usually notassociated with cold weather. In fact, carburetor icing is mostlikely when the outside temperature is between 20° F and 70° F,in conditions of visible moisture or high humidity. In 1999, 19general aviation accidents cited carburetor icing as either acause or factor. The average air temperature during theseaccidents was 65.1°, with an average dewpoint of 49.4°,equating to an approximate average relative humidity of 76%.

Air

Fuel

py Ice

etor Icing Illustration Average Temperature and Dewpoint Conditions of 

Accidents with Carburetor Icing Cause/Factor, 1999 

49.4

65.1

0

20406080

100120

Average Temperature Average Dewpoint

Degrees Fahrenheit

o

o
General Aviation Safety Issues 37

or icing conditions are more likely to occur

 warm, humid weather, accidents associated

ng may also be more likely during the spring

ths, but can occur any time during the year.

ph illustrates the number of accidents per month

re due to carburetor icing as a cause/factor.

hood of carburetor icing is related to specific

ns, the climate in certain locations is more

uretor icing accidents than in others. This map

r of accidents per state citing carburetor icing

or during 1999. Some of these accidents were

mally associated with warm, humid weather,

cidents took place in areas of the country like

 Northwest, where conditions of high relative

mon.

Carburetor icing is remedied through the use of carburetor heat,which directs air heated by hot engine exhaust into the carburetor.Operating procedures for aircraft with carbureted enginestypically recommend the use of carburetor heat whenevercarburetor ice is suspected or as a precaution whenever operatingwith reduced power, such as during landing. Although carburetedengines are most susceptible to icing during reduced powersettings, carburetor icing can occur during any phase of flight.The following graph illustrates the number of accident aircraftin each phase of flight citing carburetor icing as a cause/factor.Most accidents citing a loss of engine power due to carburetoricing occurred during cruise flight. The only phases of flight thatcarburetor icing-related engine failures did not occur were descentand landing.

ber of Accidents per Month Citing 

etor Icing as a Cause / Factor, 1999

4

0

4

1

2 2

0

1

Apr May Jun Jul Aug Sep Oct Nov Dec

1

1

1 2

2

2

1

1

1

1 2

3

1

Location of Accidents with Carburetor Icing

as a Cause/Factor, 1999
cident Data 38

arburetor air temperature gauge that

 potential icing conditions before a

ut a carburetor air temperature gauge,

roblem may be a reduction in engine

e and/or a rough-running engine. In

ready begun to form in the engine.

can be prevented or eliminated through

tor heat, the ability to identify potential

gnize the onset of ice is key to avoiding

 to carburetor icing.

 accidents are related to environmental

e resulting from fuel exhaustion or fuel

buted to the actions and/or planning of

general aviation accidents, 11 of which

gine failure due to fuel exhaustion/

uch human performance issues as

or failing to operate fuel system controls

ore common type of fuel management

n, or a lack of fuel in the aircraft fuel

57%), approximately 43% of fuel

n 1999 involved fuel starvation.

In cases of fuel starvation, the amount of fuel in the tanks mayhave been sufficient, but the fuel system was operated in such away that fuel did not get to the engine. Examples of actions thatmight result in fuel starvation include the improper operation offuel tank selector or fuel cutoff valve(s), improper operation offuel boost pump(s), or the inadvertent selection of an empty fueltank. Conversely, fuel exhaustion problems may result from anincorrect measurement of fuel onboard, a failure to calculatefuel burn properly, or the decision to fly past known fuel rangelimits.An example of an accident in 1999 with a fuel management cause/factor related to fuel starvation was the forced landing of a multiengine airplane on an instructional flight that was unable to maintainaltitude after the training pilot inadvertently turned the fuel selectorvalve off on one of the engines. Another example was the forcedlanding of a single-engine aircraft by a pilot who was unable torestart the engine after running the auxiliary tanks dry before switchingto the main tanks.

rburetor Icing Accidents by

se of Flight, 1999

0

5

2

0

Descent Maneuvering Approach Landing

Reason for Fuel Management Accidents, 1999

Fuel 

Exhaustion

56.9%

Fuel

Starvation

43.1%

62 47
39 General Aviation Safety Issues

ph illustrates the type of aircraft involved in fuel

dents in 1999. Most of these aircraft were single

anes. However, when compared to the number

wered aircraft active in general aviation, single

anes are only slightly more likely than other types

volved in fuel management accidents. Aircraft

h as the fuel capacity, fuel burn rate, and fuel

can all contribute to fuel management accidents.

ussed, most general aviation accidents occur

 and landing phases of flight. However, most

 accidents in 1999 occurred during approach

umber of fuel management accidents involving

ach to landing suggests that pilots may have

o extend their flights just beyond the maximum

aft with the fuel available.

A comparison of flight profiles for fuel management accidentsis presented in the following graph, showing that 67.0% ofaircraft involved in fuel management accidents were on pointto-point flights. In comparison to the 53.8% of all accidentaircraft in 1999 on point-to-point flights, these flights were overrepresented in fuel management related accidents. Point-topoint flights are more likely to encounter fuel managementproblems because they are typically of longer duration thanlocal flights. What is not known is whether the accident pilotsknowingly pushed the limits of aircraft range or were simplyunaware that they may have calculated fuel requirementsincorrectly. The fact that several of the accident narratives in1999 included quotes from pilots stating that they did not trustaircraft fuel quantity gauges that were indicating low fuel, eventhough they had flown for several hours, suggests that many ofthese accidents may have resulted from a combination ofplanning and decision-making errors related to fuelmanagement. Pilot decision-making may also have beeninfluenced by a general mistrust of aircraft fuel indicators thatare typically not as accurate as those in automobiles, forexample.

 of Accident Aircraft With Fuel 

nagement Cause/Factor, 1999

7

0

2

11

89

Number of Fuel Management Accidents by

Phase of Flight, 1999

10

4

36

10

39

10

0

Takeoff Climb Cruise Descent Maneuvering Approach Landing
cident Data 40

management accidents in visual and

al conditions indicates that about 97%

dents occurred in visual meteorological

age of fuel management accidents

onditions was half that of all accidents

smaller percentage of fuel management

C may be related to the higher degree

ired for instrument flights.

Because fuel management requires planning and decisionmaking, one might also expect that less experienced or lessertrained pilots would be more likely to run out of fuel than moreexperienced or more highly trained pilots due to their knowledgeof aircraft systems and experience calculating aircraftperformance. The following graph illustrates that this is not thecase. Most pilots involved in fuel management accidents in 1999held a private pilot certificate, followed closely by those holdingcommercial pilot certificates. When compared to all accidentpilots, a slightly higher percentage of private and commercialpilots were involved in fuel management accidents, while thepercentages of student and airline transport pilots were half ofthose observed for all accidents.

nt-to-Point Comparison of

ement Accidents, 1999 

Point-to- Point

67.0% 

73

Weather Conditions of Fuel

Management Accidents, 1999 

IMC

2.8%

VMC

97.2% 106 3
General Aviation Safety Issues 41

Fuel management errors also do not appear to be directly relatedto total flight experience. The flight experience of pilots involvedin fuel management accidents in 1999 ranged from student pilotswith a median of 61 total hours to airline transport pilots with amedian of 5,398 hours. The following graph illustrates that,although 26.4% of pilots involved in fuel management accidentshad 300 or fewer hours of total flight time, the percentage ofpilots with more than 1,000 hours (53.8%) was larger than thepercentage of accident pilots with fewer than 1,000 hours.

Fuel-Related Accident Pilot Total Time, 1999

(106 Pilots with Available Data)

49

20

11

6 4 5

1 2 2 0

6

0-1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 >10,000

Flight Hours

5

11 12

4

7

2

1

2

3 2

02468

101214

0-100 200 300 400 500 600 700 800 900 1,000

Highest Certificate Held by

anagement Accident Pilot, 1999 

Student

2.8%

Airline

Transport

5.5% 

None

0.9%

Highest Certificate Held by

All Accident Pilots, 1999

None

0.6%

Airline

Transport

11.6% 

Student

6.8%
cident Data 42

e statistics may be that accident pilots

ew aircraft and lacked an adequate

el system operation and/or the real

of the engines. However, the data do

assumption. Among pilots involved in

nts, 45.8% had 100 hours or fewer in

, and 8.3% had 10 or fewer hours in

are similar to those for other accident

Fuel-Related Accident Pilot Time in Aircraft Type, 1999

(96 Pilots with Available Data) 

84

8

3 1 0000000

0-1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 >10,000

Flight Hours

2 1 1 1

6 3 5 6

15

44

8

0

1020304050

0-10 0-100 200 300 400 500 600 700 800 900 1,000
43

VOLVING AMATEUR-BUILT AIRCRAFT

Aircraft

neral aviation that continues to increase in

of amateur-built aircraft. Title 14 CFR Part 2138

suance of a Special Airworthiness Certificate in

category to permit the operation of amateur

teur-built aircraft may be fabricated from plans

m a kit, so long as the major portion (51%) of

mpleted by the amateur builder(s). Personal

tional experience, aircraft performance, and

l been used as reasons39 for choosing to build

 aircraft. Evidence of the increasing popularity

an be observed in the 585% increase in the

 of active amateur-built aircraft and the 218%

mated number of annual flight hours for these

FAA began reporting40 amateur-built data in

efines an amateur-built aircraft as an aircraft, the major portion of which has been fabricated and assembled by person(s) who undertook the

ely for their own education or recreation. Commercially produced components and parts normally purchased for use in aircraft may be used including

cessories, propellers, tires, spring steel landing gear, main and tail rotor blades, rotor hubs, wheel and brake assemblies, forgings, castings, extrusions,

ardware such as pulleys, bellcranks, rod ends, bearings, bolts, rivets, etc.

 Association, frequently asked questions, at http://www.eaa.org/education/homebuilt_faq.html.

999, available at http://http://api.hq.faa.gov/GA2001/tab_1-5.pdf

Amateur-built Aircraft Flight Hours, 1993-1999

(100,000s) 

2.77

3.91

4.82 5.24

6.98 7.29

8.8

1993 1994 1995 1996 1997 1998 1999

Number of Active Amateur-built Aircraft, 1993-1999

(1000s) 

6.2

8.8 9.3

11.6

10.3

13.2

16.8

1993 1994 1995 1996 1997 1998 1999
44

ted in amateur-built aircraft representing

general aviation accident aircraft. The

uilt aircraft in the accident aircraft total

1.3% between 1993 and 1999.

9 prohibits all experimental aircraft,

from carrying persons or property for

ost of the activity involving these aircraft

onal purposes. In 1999, an estimated

828,535 of 879,54941 hours (94.2%) flown in amateur-builtaircraft were for personal / business purposes.Amateur-built Aircraft Accident ConditionsBeing certified as experimental aircraft, amateur-built aircraft alsohave specific operating restrictions42 related to the conditions inwhich they can be flown. One of these restrictions is that amateurbuilt aircraft are prohibited from flying at night or in IMC withoutspecific authorization from the FAA. Many amateur-built aircraftare able to meet this requirement by installing the flight instrumentsand equipment required43 for instrument flight, but thepercentages of aircraft certified for IFR or night flight appear tobe smaller for amateur-built than for manufactured aircraft.Although exact numbers of VFR-only and day-only aircraft arenot available, avionics data44 from the GAATA Survey indicatethat an estimated 17.4% of amateur-built aircraft have noelectrical system in contrast to only 9.5% of single-engine pistonairplanes and 8.5% of piston rotorcraft.45 Amateur-built aircraftare also less likely to have equipment necessary for IFR navigation;for example, 78.6% do not have instrument approach equipmentinstalled compared to only 33.3% of similar manufacturedairplanes.46 The effect of these differences can be observed in

the weather and lighting conditions of accidents involvingamateur-built aircraft. With very few exceptions, accidentsinvolving amateur-built aircraft occurred in day, VFR conditions.

mateur-built Accident Aircraft 

1993-1999

% 10.0% 9.6%

11.7% 11.3%

1996 1997 1998 1999

associated with amateur-built aircraft and not all experimental aircraft. This also excludes 340 hours reported in the GAATA Survey 1999

 tour operations although amateur-built aircraft are prohibited from engaging in these activities.

 operating limitations for experimental category aircraft.

 equipment requirements.

vionics installation data on a biennial basis. Avionics data from the 2000 GAATA Survey were used in this section because those data were

ilable at http://api.hq.faa.gov/GASurvey/docs/2000%20GA%20avtab_8-1.pdf.

ccident Data
45

tioned, a disproportionate number of all fatal

accidents occur at night and/or in instrument

use many amateur-built aircraft are prohibited

e conditions, it would be reasonable to expect

that a smaller percentage of amateur-built aircraft accidents mightbe fatal.Amateur-built and Manufactured AircraftComparisonsBefore attempting to compare amateur-built and manufacturedaircraft, it is again necessary to acknowledge the diverse rangeof aircraft and operations included in general aviation. In orderto make meaningful comparisons, the population ofmanufactured aircraft must be limited to a sample of similaraircraft conducting similar operations. For example, it would beinappropriate to compare accident statistics for amateur-builtaircraft with those of manufactured business jets on corporateflights. For this reason, all comparisons between amateur-builtand manufactured aircraft in this section include only singleengine piston airplanes and rotorcraft conducting personal/business flights. In 1999, 218 accidents, 60 of which were fatal,involved amateur-built aircraft, and 877 accidents, 134 fatal,involved manufactured single-engine piston airplanes androtorcraft on personal/business flights.Even with the additional operating limitations placed on amateurbuilt aircraft, the percentage of fatal accidents for amateur-builtaircraft was almost twice as high as for similar manufacturedaircraft in 1999 (27.5% versus 15.1%, respectively). Thepercentage of accidents in which the aircraft was destroyed isalso noticeably higher for amateur-built than for manufacturedaircraft (27.1% versus 17.4%, respectively). However, becausethe criteria for an aircraft being ìdestroyedî is based on the costof repair exceeding the cost of the aircraft, a direct comparisonbetween damage to amateur-built and damage to manufacturedaircraft could be misleading. Amateur-built aircraft often costless than similar manufactured aircraft, and many use compositeor fiberglass construction materials that can be more difficultand/or costly to repair.

	
	

 	 
 
	


  



 	
		

	
	

 	 
 
	


  








 
 

Accidents Involving Amateur-Built Aircraft
46

A comparison of the accident rate per 100,000 hours flownindicates that the rate is considerably higher for amateur-builtthan for manufactured aircraft. The amateur-built accident rateranged from 41.2 to 25.1 accidents per 100,000 hours between1995 and 1999, and was equal to 25.5 accidents per 100,000hours in 1999. The accident rate for manufactured, single-enginepiston airplanes and rotorcraft remained between 12.3 and 9.9per 100,000 hours during the same period. The fatal accidentrate for amateur-built aircraft decreased from a high of 11.6 fatalaccidents per 100,000 flight hours in 1995, to 6.8 fatal accidentsper 100,000 flight hours in 1999. The fatal accident rate forsimilar manufactured aircraft was only one-fourth that of amateurbuilt aircraft during the same period, ranging between 2.3accidents per 100,000 hours in 1995 and 1.5 fatal accidentsper 100,000 hours in 1999.

ccident Data

ge to Accident Aircraft, 1999

1.4% 0.0%

0.7% 0.3%

81.6%

antial Minor None

uilt Manufactured

njury per Accident Aircraft, 1999

19.7%

37.6%

9.6%

16.6%

58.6%

ous Minor None

uilt Manufactured

Accident Rate of Amateur-built and Manufactered 

Single-engine, Piston Airplanes and Rotorcraft on Personal 

Flights, 1995-1999 (per 100,000 hours)

35.1

41.2

25.1

34.8

25.5

12.3 11.7

9.9

11.7

9.9

05

1015202530354045

1995 1996 1997 1998 1999

Amateur-built Total Manufactured Total
erences in accident rate, damage, and injury

eur-built aircraft are not only more likely than

craft to be involved in an accident, but those

 more likely to result in higher levels of aircraft

upant injury. It is not clear whether these injury

ences are related to amateur-built aircraft being

of accidents that result in higher levels of injury,

rashworthiness resulting in more severe injuries

 would result from similar accidents involving

craft.

 the first occurrences for accidents involving

 manufactured aircraft supports the suggestion

e of fatal amateur-built accidents is due in part

idents in which those aircraft are involved. The

sts the 10 most frequent first occurrences of

g amateur-built aircraft. The percentages of

g those occurrences are listed for all accidents

and fatal accidents. The corresponding percentages ofmanufactured accidents and fatal accidents involving thoseoccurrences are included for comparison.The most common first occurrence among amateur-built aircraftaccidents during 1999 was a loss of control in flight. In-flight lossof control accounted for slightly more than 25% of all amateurbuilt aircraft accidents, compared to approximately 11% ofmanufactured aircraft accidents. The percentages of amateur-builtaircraft accident occurrences related to airframe, component, orsystem malfunction/failure and total loss of engine power due to

mechanical malfunction/failure were also more than double those

for similar manufactured aircraft (8.7% versus 4.0% and 6.4% versus3.0%).Broad Cause/FactorComparisons of accident causes/factors indicate an unequalproportion of aircraft-related findings among amateur-builtaccidents. The following graph illustrates the broad causes/factorscited in amateur-built accidents during 1999. Data for similarmanufactured aircraft are included for comparison. Thepercentages of accidents citing personnel causes/factors aresimilar for both types of aircraft, with a smaller percentage being

47 Accidents Involving Amateur-Built Aircraft

Accident First Occurrences, 1999

Total Fatal Total Fatal

Loss of Control - In Flight 25.7% 45.0% 10.7% 30.8%

Loss of Engine Power 15.6% 8.3% 10.2% 4.5%

Airframe/Component/System Failure/ Malfunction 8.7% 11.7% 4.0% 2.3%

Loss of Control - On Ground 8.3% 0.0% 15.2% 0.0%

Loss of Engine Power (Total) - Mech Failure/Malfunction 6.4% 1.7% 3.0% 1.5%

Loss of Engine Power (Total) - Nonmechanical 6.0% 0.0% 9.8% 4.5%

In Flight Collision With Object 4.6% 10.0% 7.6% 15.8%

In Flight Collision With Terrain/Water 4.6% 10.0% 5.3% 15.0%

Hard Landing 2.8% 0.0% 4.5% 0.0%

On Ground/Water Encounter with Terrain/Water 2.3% 0.0% 2.4% 0.0%

Amateur-built Manufactured

ent Rate of Amateur-built and Manufactered 

, Piston Airplanes and Rotorcraft on Personal 

ghts, 1995-1999 (per 100,000 hours)

11.5

8.4

9.0

6.8

3 2.2 1.8 2.1 1.5

1996 1997 1998 1999

ur-built Fatal Manufactured Fatal
craft accidents. Environmental causes/

nly 28% of amateur-built accidents

idents involving manufactured aircraft.

 percentage of environmental causes/

ctured and amateur-built aircraft is no

 more amateur-built than manufactured

 flying in instrument weather conditions,

 a large percentage of fatal accidents in

e fewer amateur-built aircraft fly in IMC,

 weather-related hazards is smaller. If

elated risk were similar for both amateur

ctured aircraft operations, the disparity

 fatal accident rates for the two types of

ven greater.

ultiple findings for a single accident, the sum of the subcategory values may be greater than the category total.

48 

Accident Data

tor of Amateur-built and 

ed Aircraft Accidents, 1999

28.0%

86.7%

44.0%

91.0%

Environment Personnel

eur-built Manufactured

Other than the difference in causes and factors related to specificoperating limitations placed on some amateur-built aircraft, themost meaningful difference between manufactured and amateurbuilt aircraft accidents is the percentage of causes and factorsattributed to the aircraft. Aircraft related causes/factors were citedin 38.1% of amateur-built accidents, but only 27.3% ofmanufactured aircraft accidents. To further illustrate thosedifferences, the following graph includes a comparison of aircraftcauses and factors by the next level of subcategories.47Of the 218 amateur-built and 869 manufactured aircraft accidentsduring 1999 with findings available, amateur-built aircraft werenearly twice as likely to have cited a cause/factor related to the

Aircraft-related Cause/Factors of Accidents 

Involving Amateur-built and Manufactured Aircraft, 1999

0.5%

0.0%

0.5%

1.4%

4.5%

1.4%

1.6%

8.4%

11.3%

0.0%0.0%

0.5%

1.8%

3.2%

4.1%

4.6%

6.9%

22.0%

 Aircraft Performance

 Engine Power Loss

 Instruments

 Systems and

Equipment

 Landing Gear Flight Control

Systems

 Aircraft Structure

 Fluid

Powerplant/Propulsion

Amateur-builtManufactured
49 Accidents Involving Amateur-Built Aircraft

nt. Although a smaller percentage of accidents

 cited aircraft structure and flight control

e, the disparity between groups was even greater,

 aircraft being more than 2.5 times more likely

blems. Manufactured aircraft only exceeded

raft in the percentage of causes/factors related

nd landing gear.

al difference between amateur-built and

raft accidents is pilot flight experience. However,

ing amateur-built aircraft appear to have, on

perience than accident pilots flying manufactured

ge age of accident pilots in 1999 was 52.8 years

t aircraft and 49.7 years for comparable

craft. As the following charts illustrate, similar

ident pilots held commercial pilot certificates, and

of amateur-built aircraft pilots held ATP certificates.

rtificate Held by Accident Pilot of

Amateur-built Aircraft, 1999 

Commercial

23.9%

Student

5.5%

None

2.3%

Airline

Transport

11.5% 

The average flight experience of accident pilots flying amateurbuilt aircraft also appears to be similar to that of accident pilotsin 1999 flying similar manufactured aircraft. Of the 209 amateurbuilt aircraft pilots with total flight time data available, 55.5%had 1,000 or fewer hours of total time, and 25.4% had 300 orfewer hours.

Certificate Held by Accident Pilot of

Manufactured Aircraft, 1999 

Commercial

22.8%

Private

67.3%

Student

1.4%

None

0.6%

Airline

Transport 

8.0%

Amateur-built Aircraft Accident Pilot Total Time, 1999

Flight Hours

05

1015202530

0-100 200 300 400 500 600 700 800 900 1,000

10 10

26

17 16

9

5 3

12

8

0-1000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 >10,000

116

31

15 13 11

2 4 0 2 3

12
% of accident pilots flying similar

d 1,000 or fewer hours of total flight

0 hours or fewer.

r-built and manufactured aircraft appear

gard to the number of hours of flight

. Among pilots of amateur-built aircraft

3% had 1,000 or fewer hours in make

ad 10 hours or fewer.

In comparison, for the pilots for whom data are available, 92.3%of those flying manufactured aircraft had 1,000 or fewer hours inmake and model of accident aircraft, and only 6.8% had 10hours or fewer. One reason for this difference may simply be thatamateur-built aircraft are not as common. Pilots of amateur-builtaircraft may have fewer hours in make and model because theydo most of their flying in manufactured aircraft and at some pointhave transitioned to amateur-built aircraft, while pilots ofmanufactured aircraft continue to fly the same make and model.An additional fact worth noting is that 9 of the 31 accident pilotswith fewer than 10 hours in aircraft make and model accumulatedthose hours in newly completed aircraft.

50 

ccident Data

20406080

100120140

0

175

3 0 0 00 0 000 0

0-1,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 10,000 >10,000

Amateur-built Aircraft Accident Pilot Time in Aircraft Type, 1999

2

31

118

24

8 2 9 4 4 2 2

Flight Hours

0-10 0-100 200 300 400 500 600 700 800 900 1,000

aft Accident Pilot Total Time, 1999

Flight Hours

00 200 300 400 500 600 700 800 900 1,000

4

45

125

75 68

32 35

24 25 32

,000 6,000 7,000 8,000 9,000 10,000 >10,000

21 25 12 12 4 5 46
In summary, the accident data suggest that although the disparity

between manufactured and amateur-built aircraft is decreasing,amateur-built aircraft are still more likely to be involved in anaccident. Furthermore, the data also suggest that accidentsinvolving amateur-built aircraft are likely to result in higher levelsof injury and/or aircraft damage than are accidents involvingsimilar manufactured aircraft conducting similar operations.Finally, comparisons of accident occurrences, cause/factorfindings, and pilot-specific data suggest that these results areprimarily due to aircraft-specific differences.

51 Accidents Involving Amateur-Built Aircraft

rcraft Accident Pilot Time in Aircraft Type, 1999 

Flight Hours

2 3 0 00 00 0

350300250200150100

50

0

0-10 0-100 200 300 400 500 600 700 800 900 1,000

52

302

135

59 46

24 17 20 20 16 14

4,000 5,000 6,000 7,000 8,000 9,000 10,000 >10,000
s page left intentionally blank.
53

FETY BOARD SEVERITY CLASSIFICATIONS

general aviation accident is classified by the

ury (that is, fatal, serious, minor, or none) and

mage (that is, destroyed, substantial, minor, or

HIGHEST LEVEL OF INJURY

 that results in death within 30 days of the 

jury that (1) requires the individual to be

ore than 48 hours, commencing within 7 days

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

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

morrhages, nerve, muscle, or tendon damage;

ternal organ; or (5) involves second- or third

any burns affecting more than 5% of the body

 that 

is neither fatal nor serious.

oes not define ìdestroyed.î This term is difficult to define because aircraft are sometimes rebuilt even when it is not economical to do so.

DEFINITIONS FOR LEVEL OF AIRCRAFT DAMAGE

Destroyed - Destroyed Damage due to impact, fire, or in-flight failures tothe extent that the aircraft cannot be repaired economically.60Substantial Damage - Substantial Damage Damage or failure that adversely affectsthe structural strength, performance, or flight characteristics ofthe aircraft and that would normally require major repair orreplacement of the affected component. Engine failure ordamage limited to an engine if only one engine fails or isdamaged, bent fairings or cowling, dented skin, small punctureholes in the skin or fabric, ground damage to rotor or propellerblades, and damage to landing gear, wheels, tires, flaps, engineaccessories, brakes, or wingtips are not considered ìsubstantialdamage.î61Minor Damage ñ Any damage Minor Damage that neither destroys the aircraftnor causes substantial damage (see definition of substantialdamage for details).None ñ No damage. None
tation Safety Board

on Safety Board investigates every civil

urs in the United States. It also provides

s U.S.-Accredited Representatives as

treaties for aviation accidents overseas

aircraft or involving aircraft or major

facture.62 Investigations are conducted

quarters in Washington, D.C., or from

ces in the United States (see Appendix D).

 cause(s) of an accident, investigators

s, and circumstances. The objective is

and effect relationships in the accident

something can be done to prevent

accident under consideration.

etween the population of accidents

 Board and those that are included in

aft Accident Data, U.S. General Aviation.

 is mandated by Congress to investigate

 that occur on U.S. soil (including those

nd foreign operators), the Annual Review

ccurred among U.S.-registered aircraft

 about the criteria for Safety Board investigation of an aviation accident or incident, see 49 CFR 831.2.

54
ansportation Safety Board Aviation

nt Database

nsportation Safety Board is responsible for

vernmentís database on civil aviation accidents.

ís Accident/Incident Database is the official

tion accident data and causal factors. The

blished in 1962 and approximately 2,000 new

added each year.

dent Database is primarily composed of aircraft

ccidentî is defined in 49 CFR 830.2 as ìan

ated with the operation of an aircraft which

en the time any person boards the aircraft with

ght and all such persons have disembarked,

 person suffers death or serious injury, or in

receives substantial damage.î The database

lect number of aviation ìincidents,î defined in

s ìoccurrences other than accidents that are

e operation of an aircraft and that affect or

afety of operations.î

ators use the Safety Boardís Accident Data

tem (ADMS) software to enter data into the

Database. Shortly after the event, a preliminary

a few data elements, such as date, location,

, type of aircraft, etc., becomes available.

 with additional information concerning the

able within a few months. A final report, which

nt of the probable cause and other contributinge completed for months after the investigation

ed.

55

An accident-based relational database is currently availableto the public at http://www.ntsb.gov/ntsb/query.asp#query_start.It contains records of approximately 40,000 accidents andincidents that occurred between 1982 and the present. Eachrecord may contain more than 650 fields of data concerningthe aircraft, event, engines, injuries, sequence of accident events,and other topics. Individual data files are also available fordownload at ftp://www.ntsb.gov/avdata, including one completedata set for each year beginning with 1982. The data files are inMicrosoft Access (.mdb) format and are updated monthly. Thisdownload site also provides weekly ìchangeî updates andcomplete documentation.
Anchorage

ALASKA

Parsippany

MID ATLANTIC

Washington DC

Atlanta

SOUTHEAST

Miami

NORTH CENTRAL

Chicago

SOUTH CENTRAL

NORTHWEST Seattle

SOUTHWEST

Gardena

Mid-Atlantic Regional Office490 L’Enfant Plaza, S.W. Washington, D.C. 20594 Phone: 202-314-6320 FAX: 202-314-63298:30 a.m.-5 p.m. (Eastern) 

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 Office2001 Route 46Suite 504 Parsippany, New Jersey 07054Phone: 973-334-6420 FAX: 973-334-67598:30 a.m.-5 p.m. (Eastern)

Southeast Regional Office

8405 N.W. 53rd StreetSuite 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, SWSuite 3M25Atlanta, Georgia 30303-3104 Phone: 404-562-1666 FAX: 404-562-16748 a.m.-4:30 p.m. (Eastern)

Alaska Regional Office222 West 7th Avenue Room 216, Box 11Anchorage, Alaska 99513Phone: 907-271-5001FAX: 907-271-30078 a.m.-4:30 p.m (Alaska) 

North Central Regional Office 31 West 775 North AvenueWest 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: 303-361-06197:30 a.m.-4 p.m (Mountain)

Denver

CENTRAL MOUNTAIN

Arlington

SOUTHERN

NORTHEAST

56

on Safety Board Regional Offices1