human factors challenges in poor visibility helicopter operations … · human factors challenges...

Human Factors Challenges in Poor Visibility Helicopter Operations

Patrizia Knabl

German Aerospace Center (DLR) Institute of Flight Guidance Department of Pilot Assistance Systems PACDEFF 2015 Brisbane, Australia

25-27 August

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DVE in military and civil helicopter operations

Superimposed displays to assist in DVE conditions

Recent DLR activities and selected findings

Conclusions / outlook

Outline

> Knabl • PACDEFF > Brisbane, Australia > 2015

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Brownout

Responsible for 75% of mishaps in NATO member countries US Services’ largest overall cause of rotary-wing airframe loss

Spatial disorientation

unawareness of lateral drifts prior to touchdown type I (unrecognized)

illusion of self-motion (vection) the movement of the dust particles provokes the impression of banking or turning when in a level hover

somatogravic illusion impression of pitching down when decelerating from forward flight

Consequences such as roll-over, CFIT and collision with obstacles or

other aircraft

Helicopter flight in degraded visual environment (DVE) Military operations


(NATO report HFM Task Group 162, 2012)

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Helicopter flight in degraded visual environment (DVE) Civil operations

External environmental awareness

listed among the top 3 most relevant factors of European civil rotary-wing accident causes

(van Hijum & Masson, 2010)

Adverse weather

2nd most common accident factor

accounts for the largest number of deaths (40%)

(accidents in the Gulf of Mexico from 1983 -2009)

(Baker et al.,2011)

darkness (48%) bad weather (17%)

both especially associated with fatal outcome

(based on NTSB records 1983-2005)

(Baker et al., 2006)

SITUATIONAL AWARENESS WORKLOAD

SPATIAL DISORIENTATION FLIGHT SAFETY


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Helmet-Mounted Displays (HMD) Introduction


+ reduced head-down time + divided attention task benefits + reduced eye accommodation + conformal symbology + flight performance + lower WL + higher SA

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Cost in detecting unexpected events in the world particularly if these events are not salient Meta-analysis by Fadden et al. (1998); Fischer et al. (1980), Larish & Wickens (1991); Wickens & Long (1994); Wickens (1997)

Inattentional blindness Failure to notice a highly visible yet unexpected object in the visual field, caused by a lack of attention (Mack and Rock, 1992, 1998) Wickens & Long, 1994

DLR

Helmet-Mounted Displays (HMD) / Head-up Displays (HUD) Unexpected event detection cost


Clutter

Attentional tunneling Longer than optimal allocation of attention at the cost of neglecting events on other channels, or failing to perform other tasks

(Wickens, Alexander, 2009)

DLR HMD activities Overview

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SIM study 1 SIM study 2

• 12 pilots • German Armed Forces • German Federal Police • 3925 (3078) flight hours • 4 VFR, 8 IFR • 1 HMD experience • 10 brownout experience

• 18 pilots (9 civil, 9 mil) • German Armed Forces • German Federal Police • German and Swiss Air rescue • 1 VFR, 17 IFR • 4401 (3867) flight hours • age 45 (7) • 4 HMD real flight experience • 6 HMD sim experience

Flight and landing performance Concurrent task performance Expected and unexpected

event detection

Workload (HR/HRV, NASA TLX) Situation awareness (SART) Acceptance / usability Visual, perceptual, somatic issues with HMD


Generic Cockpit Simulator (GECO)

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Resolution 2 x 1920 x 1200 pixel @ 60 Hz

Field of view binocular, 2 x 80° x 40°

Head tracker magnetic, 400 Hz, accuracy 0,25°

Weight ~ 2,3 kg

Color Monochrome green (stereo able)

Airbus 350 cockpit layout

3 high resolution projectors (area of 180° by 40°)

Rotary-wing flight controls (cyclic, collective, yaw)

Flight dynamics of EC 135

JEDEYE HMD, Elbit Israel


Simulation environment Overview

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Task design Event expectancy


Expected Unexpected

Near domain Far domain Near domain Far domain

monitoring task speed altitude route

target search and identification

LOW FUEL WARNING obstacles/traffic

in flight route

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Findings Unexpected warning on display


Longer RT with HMD if warning:

occurred in poor visibility

was truly unexpected

Poor visibility

attention primarily focused on outside scene time-critical search task

obstacle avoidance

maintain stable attitude

0,0

1,0

2,0

3,0

4,0

5,0

6,0

first second

reac

tion

time

(s)

appearance

poor visibility

HMDBaseline

0,0

1,0

2,0

3,0

4,0

5,0

6,0

first second

reac

tion

time

(s)

appearance

average visibility HMDBaseline

Salience alone did not aid rapid detection on the HMD, but added expectancy did.

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Findings Unexpected traffic in flight route


366,5

444,3

HMD PFD/ND

Distance at start of avoidance maneuver (m)

Tendency towards a detection cost with the HMD!

descriptive results indicate later start of avoidance

maneuver

vertical maneuver more frequently selected with HMD

less time for adequate avoidance plan (pilot comments)

one pilot did not detect it at all!

no collision

lateral maneuver was most frequently selected

no significant differences in starting point of collision

avoidance

following Wickens (2005)

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Findings Target detection


0,36

0,69 0,52

0,61

0,79

0,70

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1,0

HMD HMD cue base

Hit

rate

Display type

pooraverage

Display: F(2, 32) = 26.44, p = .000, η²p = .623 Visibility: F(1, 16) = 60.48, p = .000, η²p = .791 Interaction:F(2, 32) = 8.58, p = .001, η²p = .349

High task difficulty

74% HMD cued

61% baseline

48% HMD un-cued

Detection cost for HMD un-cued targets!!

Findings Target detection

DLR.de • Chart 13

NONE-HITS RESULTED RATHER FROM A FAILURE IN CUE DETECTION THAN TARGET DISCRIMINATION

Participants did not respond to more than 20% of the cued

targets!

All targets were visible No target was never detected

Visibility issue

Cue precision and reliability issue

Highly precise Highly reliable

False alarm issue

FA rate very low! Tendency to respond

even under uncertainty (more FA)


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Conclusions


Flight performance

Landing performance

Pilot acceptance

Usability

Workload

Situation awareness

Clutter

Attention fixation (especially 2D symbology)

Unexpected event detection

Expected far domain event detection

Outlook

DLR.de • Chart 15 > Knabl • PACDEFF > Brisbane, Australia > 2015

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QUESTIONS ?

———————————————————— German Aerospace Center (DLR)

Institute of Flight Guidance | Pilot Assistance Patrizia Knabl

Telephone: +49 531 295-2163 Mail: [email protected]

mailto:[email protected]

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