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Eject! Eject! Eject! – Human Factors in Delayed Ejection

Once the decision to abandon the aircraft is taken, the only action required is to fire the seat by pulling the seat-firing handle. This does not take more than a second or two, yet Air Forces the world over have lost pilots, experienced and rookie, because they waited too long to eject. The human factors  involved in such delays are several. The same are discussed here briefly.

Delay in Decision Making.  Decision to eject involves recognition of emergency and coming to a conclusion that no other action is compatible with safety and survival. Both require information processing and decision making. Delay in decision making is avoided by thorough and repetitive training on ground and correct pre-flight briefing procedure.

Delayed Action.  Action to initiate ejection is delayed due to several reasons.

(a) Fear of the unknown. The cockpit environment is known to the pilot and he feels safe in it. To leave such an environment and ‘jump’ into thin air is a new experience and one may feel quite unsafe or disinclined to do it till it is too late.

(b) Fear of victimisation or ridicule. It is an accepted fact that no pilot chooses to eject if he can help it. Pilots who have ejected once and were harangued for the accident have often been known to delay ejection the next time.

(c) Past success with or without recognition.  Success in bringing back a disabled aircraft with very marginal control is an event that induces a sense of pride. This self-appreciation is transmitted into a high level of confidence if the performance also gets recognition in the form of appreciation or commendation. Whenever the next occasion arises, such a pilot may again be likely to do ‘his best’ and may delay ejection till it is too late.

(d) Saving the civilian population.  When an emergency occurs while flying over populated areas, pilot may choose to fly the disabled aircraft away from habitation.  The pilot may eject once he accomplishes the intended action of saving the civilians on ground, but many a time at the cost of his own life.

(e) Professional Pride.  This is a necessary quality for all pilots but it is a double-headed monster. For example, an experienced pilot had runaway tail trim in an aircraft type on which he was converting. The aircraft bunted viciously and the pilot made a few quick checks to find the cause to remedy the situation. Since he was not yet ‘hot’ on the aircraft, and his correct actions did not help, he decided to eject. He had a safe ejection. In a similar situation, an experienced test pilot went nose diving into the ground.

(f) Communication in multi-seat aircraft.  This is a problem with trainer aircraft or those twin crew aircraft without command ejection. Escape from such an aircraft requires specified procedure to be followed. R/T defects or lack of understanding or communication by one of the pilots, delays the ejection. Good R/T and proper briefing between the two pilots is vital for successful ejection, particularly when time is at a premium. In tandem seat aircraft with two pilots, the average time to eject is 6 to 11 seconds.

(g) Pre-ejection drill. This is not a problem in most of the advanced aircraft, except for some old generation aircraft with seats requiring many actions by the pilot before ejection. Pilots of such aircraft must be thorough with the drill and practice it at frequent intervals to get familiar with the sequence of pre-ejection serial actions.

Physical, Physiological or Psychological factors. These factors cause temporary incapacitation to operate the ejection seat firing handle.

(a) Excessive positive or negative ‘G’.  Ejection during high-G turns, resulting in positive G (+Gz) may cause physical incapacity to pull ejection handle. Negative G (-Gz)is worse in its effects as it renders the pilot unstable in the cockpit with increased distance between pilot’s hands and the ejection handle.

(b) Physical injuries.  Mid-air collision, bird strike etc. may injure the eyes, face or head. This may render the pilot incapacitated or unable to act quickly.

(c)  Physiological.  Hypoxia, decompression sickness, acute decompression, toxic fumes may delay ejection because of physical/ mental incapacitation.

(d) Psycho-/ Physiological Factors.  As per the type of personality and the type of the emergency, sometimes some pilot may panic and ‘freeze’ on controls, not able to take decisive actions.

(e) Disorientation. Certain aircraft emergencies such as lateral control failure, tail trim runaway or badly performed aerobatic manoeuvres such as roll of the top or barrel roll, may cause disorientation. In such a confused state the pilot may delay ejection.

Vital Points for Safe Ejection

  • Know your ejection seat well.
  • Practice ejection drills, especially if you have not flown for some time or have changed type of aircraft.
  • Aircraft is expensive but your life is invaluable.
  • Ensure that seat safety pin is removed before you start up your aircraft.
  • Each pilot must undergo periodic training on Ejection Procedure Simulator.

 

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Reference

1. Ernsting’s Aviation Medicine. Rainford DJ, Gradwell DP (Editors). 4th Edition. Hodder Arnold, London 2006.

2. Fundamentals of Aerospace Medicine. DeHart RL, Davis JR (Editors). 3rd Edition. Lippincott, Williams & Wilkins, Philadelphia 2002.

Acknowledgement.  Image courtesy Wikimedia Commons

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