Spatial Disorientation in Military Aviation

Spatial Disorientation in Spatial Disorientation in Military AviationMilitary Aviation

LT Kelly R. Johnson, Ph.D.15 November 2000

What is Spatial Disorientation?What is Spatial Disorientation?

• SD occurs when– “the aviator fails to sense correctly the position,

motion, or attitude of his aircraft or of himself within the fixed coordinate system provided by the surface of the earth and the gravitational vertical.”

• This includes– “the erroneous perception of the aviator’s own

position, motion, or attitude to his aircraft, or of his aircraft relative to another aircraft.”

Why do Why do aviators aviators becomebecome

…and other misconceptions

Previous Mishap Previous Mishap ResearchResearch

GillinghamGillingham, K.K. (1992). The spatial disorientation , K.K. (1992). The spatial disorientation problem in the United States Air Force. problem in the United States Air Force. Journal ofJournal of VestibularVestibular Research, 2Research, 2: 297 : 297 -- 306.306.

Total Operationsrelated

SDrelated

LSArelated

SD/LSArelated

Mishaps 633 356 81 263 270Fatalities 795 515 115 425 437Cost(US$)

4,452M 2,558M 539M 2,012M 2,045M

BellenkesBellenkes, A. et al. (1992). Spatial disorientation in , A. et al. (1992). Spatial disorientation in Naval aviation mishaps: A review of class A Naval aviation mishaps: A review of class A incidents from 1980 incidents from 1980 -- 1989. 1989. Aviation, Space, Aviation, Space, and Environmental Medicine, 63and Environmental Medicine, 63: 128 : 128 -- 131.131.

All mishaps Helo Prop Jet

# SD mishaps 33 11 1 21Fatalities 37 28 0 9

Fatalities/mishap 1.12 2.55 0.00 0.43

Mean flight hours 1458.6 1945.2 1164.0 1266.6

BraithwaiteBraithwaite, M.G. et al. (1998). Spatial disorientation , M.G. et al. (1998). Spatial disorientation in U.S. Army rotaryin U.S. Army rotary--wing operations. wing operations. Aviation, Aviation, Space, and Environmental Medicine, 69Space, and Environmental Medicine, 69: 1031 : 1031 --1037.1037.

Factor SD Accidents Non-SD AccidentsTotal number of accidents 299 694% of all accidents 30.8 69.2% of class A accidents 36 18Total cost of accidents $46.79 million $49.95 millionAverage cost per accident $1.62 million $0.74 millionTotal lives lost 110 93Average lives lost per accident 0.38 0.14M ean height above ground at emer. 65 ft 455 ftM ean airspeed at time of emergency 28 knots 44 knots

Naval Safety Center: FY90 Naval Safety Center: FY90 -- FY96FY96

Aircraft SD Totalaircraft

Fatalities Cost

All aircraft 58 64 88 $956.93 M

Tacair 32 37 26 $778.57 M

Rotary 23 23 30 $88.02 M

Fixed Wing/non-ejection

3 4 32 $90.34 M

NAMRL Mishap ResearchNAMRL Mishap Research

• Mishap review– US Navy and Marine Corps– Class A flight Mishaps– Fiscal Years 90 through 98

• 392 mishaps (USN-248; USMC-146)

• Methods– Braithwaite et al. SD

categorization

Categorization of the Spatial Categorization of the Spatial Disorientation AccidentDisorientation Accident

Category Definition

1 SD was the “major” component of the accidentsequence (all other contributory factors wouldnormally have been overcome without mishap)

2 SD was a “subsidiary” component of the accidentsequence (other contributory factors would haveled to a mishap in any case, but SD made theaccident sequence more difficult to deal with orthe outcome more severe)

3 SD was an “incidental” component (SD occurredbut did not affect the outcome)

4 SD did not occur

5 The role of SD was unknown

Naval Safety Center Reports:Naval Safety Center Reports:FY90 FY90 -- FY98FY98

SD mishaps Non-SD mishaps

# mishaps 51 341

% of total mishaps 13% 87%

Fatalities 104 267

Fatalities/mishap 2.04 0.78

Mean flight hours 1730.25 1606.78

Mean hours in type 662.8 742.91

NVG’s in use 8 22

Mishaps (SD & NonMishaps (SD & Non--SD) per YearSD) per Year

Total USN USMCFY90 65 38 27FY91 60 39 21FY92 55 38 17FY93 53 34 19FY94 28 17 11FY95 34 21 13FY96 36 21 15FY97 27 15 12FY98 36 25 12

Class A Mishaps: FY90 Class A Mishaps: FY90 -- FY98FY98

FY90 FY91 FY92 FY93 FY94 FY95 FY96 FY97 FY98

6560

5553

2834 36

2736

0

10

20

30

40

50

60

70

# M

isha

ps

Year


SD

Non-SD

49

38 4036

2027

2118

27

1219

12 16

7 613

7 90

10

20

30

40

50

# M

isha

ps

Year

Spatial Disorientation (SD)Spatial Disorientation (SD) vsvs. . NonNon--SD MishapsSD Mishaps

SDSD vsvs. Non. Non--SD mishaps:SD mishaps:Phase of flightPhase of flight

8.914.7

7462.8

16.822.5

01020304050607080

Perc

enta

ge o

f mis

haps

Takeoff Inflight Landing

Phase of flight

SD

Non-SD

SDSD vsvs. Non. Non--SD Mishaps:SD Mishaps:Time of dayTime of day

56.4

81.6

43.6

18.4

0102030405060708090

Per

cent

age

of m

isha

ps

Day Night

Tim e of day

SD

Non-SD

SDSD vsvs. Non. Non--SD Mishaps:SD Mishaps:Type of aircraftType of aircraft

25.7 26.3

5.9 4.4

68.3 69.3

0

10

20

30

40

50

60

70

Per

cent

age

of m

isha

ps

Helo Prop Jet

Type of a ircra ft

SD

Non-SD

SD mishaps: Aircraft type and SD mishaps: Aircraft type and time of daytime of day

818

5 1

43

26

01020304050

# M

isha

ps

Helo Prop Jet

Type of Aircraft

Day

Night

Meteorological Conditions for All Meteorological Conditions for All SD MishapsSD Mishaps

VMC67%

IMC33%


USMC

USN

38 39 3834

1721 21

15

252721

17 19

11 13 1512 110

10

20

30

40

# M

isha

ps

Year

USN and USMC Mishaps: USN and USMC Mishaps: FY90 FY90 -- FY98FY98

Spatial Disorientation Mishaps: Spatial Disorientation Mishaps: USNUSN vsvs. USMC. USMC


USMC

USN

911

8

12

3 4

8

46

3

8

4 4 4

2

5

3 30

2

4

6

8

10

12

# M

isha

ps

Year

SD mishaps in the Navy and Marine SD mishaps in the Navy and Marine Corps: Type of aircraftCorps: Type of aircraft

52.2

2.1

45.7

18.57.7

73.8

01020304050607080

Perc

enta

ge o

f Mis

haps

USMC USN

Branch

HeloPropJet

Overall FindingsOverall Findings

Factor SD Non-SD

# mishaps 101 276

% Mishaps 26 70

Total Lives 172 168

Avg lives/Acc 1.70 0.61

Mean flight hours 1690.3 1494.9

Mean hours in type 686.1 611.2

NVG’s in use 20 10

ConclusionsConclusions

• Spatial disorientation plays a larger part in military aviation mishaps than previously indicated

• Mishaps due to spatial disorientation claim nearly three times more lives than non-SD mishaps

• Pilots-at-controls are often very experienced aviators

• The influence of Night Vision Devices appears to be under reported in aviation mishaps. – Further research into training methods and HUD

symbology may be warranted

Thank YouThank You

To Contact:LT Kelly R. Johnson, Ph.D.Naval Aerospace Medical Research Lab51 Hovey Road Pensacola, FL 32507-1046Ph.: 850-452-2048 (DSN: 922)Fax: 850-452-9290Email: [email protected]

Documents

Spatial Disorientation in Military Aviation