Human Factors Challenges in Poor Visibility Helicopter Operations

Transcription

1 DLR.de Chart 1 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 August

2 DLR.de Chart 2 Outline DVE in military and civil helicopter operations Superimposed displays to assist in DVE conditions Recent DLR activities and selected findings Conclusions / outlook

3 DLR.de Chart 3 Helicopter flight in degraded visual environment (DVE) Military operations 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 (NATO report HFM Task Group 162, 2012)

4 DLR.de Chart 4 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 ) (Baker et al.,2011) darkness (48%) bad weather (17%) both especially associated with fatal outcome (based on NTSB records ) (Baker et al., 2006) SITUATIONAL AWARENESS WORKLOAD SPATIAL DISORIENTATION FLIGHT SAFETY

5 DLR.de Chart 5 Helmet-Mounted Displays (HMD) Introduction + reduced head-down time + divided attention task benefits + reduced eye accommodation + conformal symbology + flight performance + lower WL + higher SA

6 DLR.de Chart 6 Helmet-Mounted Displays (HMD) / Head-up Displays (HUD) Unexpected event detection cost 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) Wickens & Long, 1994 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) 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

7 DLR.de Chart 7 DLR HMD activities Overview SIM study 1 SIM study 2 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 12 pilots German Armed Forces German Federal Police 3925 (3078) flight hours 4 VFR, 8 IFR 1 HMD experience 10 brownout 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

8 DLR.de Chart 8 Simulation environment Overview Generic Cockpit Simulator (GECO) 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 Resolution 2 x 1920 x Hz Field of view binocular, 2 x 80 x 40 Head tracker magnetic, 400 Hz, accuracy 0,25 Weight Color ~ 2,3 kg Monochrome green (stereo able)

9 DLR.de Chart 9 Task design Event expectancy Expected Unexpected Near domain Far domain Near domain Far domain monitoring task target search and identification LOW FUEL WARNING obstacles/traffic in flight route speed altitude route

10 DLR.de Chart 10 Findings Unexpected warning on display Longer RT with HMD if warning: occurred in poor visibility was truly unexpected reaction time (s) 6,0 5,0 4,0 3,0 2,0 1,0 0,0 poor visibility HMD Baseline first second appearance Poor visibility attention primarily focused on outside scene time-critical search task obstacle avoidance maintain stable attitude Salience alone did not aid rapid detection on the HMD, but added expectancy did. reaction time (s) 6,0 5,0 4,0 3,0 2,0 1,0 0,0 average visibility HMD Baseline first second appearance

11 DLR.de Chart 11 Findings Unexpected traffic in flight route Distance at start of avoidance maneuver (m) no collision lateral maneuver was most frequently selected no significant differences in starting point of collision avoidance 366,5 HMD 444,3 PFD/ND 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! following Wickens (2005)

12 DLR.de Chart 12 Findings Target detection 1,0 Hit rate 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,61 0,36 0,79 0,69 0,70 0,52 High task difficulty 74% HMD cued 61% baseline 48% HMD un-cued 0,2 0,1 0,0 poor average HMD HMD cue base Display type Detection cost for HMD un-cued targets!! 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

13 DLR.de Chart 13 Findings Target detection Visibility issue Cue precision and reliability issue False alarm issue Highly precise Highly reliable All targets were visible No target was never detected Participants did not respond to more than 20% of the cued targets! FA rate very low! Tendency to respond even under uncertainty (more FA) NONE-HITS RESULTED RATHER FROM A FAILURE IN CUE DETECTION THAN TARGET DISCRIMINATION

14 DLR.de Chart 14 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

15 DLR.de Chart 15 Outlook

16 DLR.de Chart 16 QUESTIONS? German Aerospace Center (DLR) Institute of Flight Guidance Pilot Assistance Patrizia Knabl Telephone: Mail: