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From SKYbrary Wiki
Pilot Incapacitation is the term used to describe the inability of a pilot, who is part of the operating crew, to carry out their normal duties because of the onset, during flight, of the effects of physiological factors.
Death is the most extreme example of incapacitation, usually as a result of a heart attack, but is not necessarily the most hazardous. Although most recorded deaths of operating pilots in flight have been found to be due to cardiovascular disease, by far the most common cause of flight crew incapacitation is gastroenteritis.
Incapacitation may occur as a result of:
- The effects of Hypoxia (insufficient oxygen) associated with an absence of normal pressurisation system function at altitudes above 10,000 ft.
- Smoke or Fumes associated with an Fire in the Air or with contamination of the air conditioning system.
- Gastro-intestinal problems such as severe Gastroenteritis potentially attributable to Food Poisoning, or to Food Allergy.
- Being asleep.
- A medical condition such as a heart attack, stroke or seizure, or transient mental abnormality.
- A Bird Strike or other event causing incapacitating physical injury.
- A malicious or hostile act such as assault by an unruly passenger, terrorist action or small arms fire, or possibly malicious targeting of aircraft with high powered lasers by persons on the ground.
Unless the incapacitation occurs on a single pilot operation, incapacitation of one pilot may not be immediately obvious, become only progressively evident, or escape notice altogether until an unexpected absence of response or action occurs.
Clearly, if the single pilot of a small aircraft becomes incapacitated then the safety of the flight is liable to be severely compromised and Loss of Control may result. However, for the two pilot case typical of larger transport aircraft, incapacitation of only one of the pilots is unlikely to present a significant risk given the attention which pilot training, especially for low minima precision approaches, is usually required to give to the implications of single pilot incapacitation.
Loss of Separation may be a secondary effect of total crew incapacitation or side effect of the additional workload imposed upon the remaining crew member(s).
The key to avoiding serious problems from the incapacitation of one pilot in a multi crew aircraft is the availability of appropriate SOPs and recurrent training which includes practice in their use.
Correct control of both the aircraft pressurisation system and, if necessary, use of the emergency oxygen supply will both prevent Hypoxia and protect the crew from the effects of Smoke and Fumes. Therapeutic Oxygen supplies can also alleviate the condition of a crew member or passenger suffering a medical condition. Staggering crew meal times and ensuring that each pilot eats different meals both prior to and during flight, will usually prevent both pilots becoming incapacitated due to Food Poisoning and is currently common practice. Intentional sleep whilst on the flight deck may be relevant on long haul flights but should only take place if an appropriate SOPs exists and is followed.
The first indication that a controller might get of total flight crew incapacitation is Loss of Communication. Having tried all means, without success, to contact the aircraft, it is extremely difficult for a controller to ascertain what is happening on an aircraft. If the aircraft autopilot is engaged then it will be likely to follow the flight plan route towards the destination. Conforming with standard loss of communication procedures, military aircraft can be tasked to intercept the aircraft and inspect it visually but there is little that a controller can do other then ensure the safety of surrounding traffic by maintaining separation.
Accidents & Incidents
Events on the SKYbrary Database which list Incapacitation as a causal factor:
- A319, vicinity Glasgow UK, 2018 (On 30 September 2018, an Airbus A319 Captain had to complete a flight into Glasgow on his own when the First Officer left the flight deck after suffering a flying-related anxiety attack. After declaring a ‘PAN’ to ATC advising that the aircraft was being operated by only one pilot, the flight was completed without further event. The Investigation found that the First Officer had been “frightened” after the same Captain had been obliged to take control during his attempted landing the previous day and had “felt increasingly nervous” during his first ‘Pilot Flying’ task since the event the previous day.)
- A320, vicinity Abu Dhabi UAE, 2012 (On 16 November 2012, Captain of an A320 positioning for approach to Abu Dhabi at night became incapacitated due to a stroke. The First Officer took over control and declared a MAYDAY to ATC. The subsequent approach and landing were uneventful but since the First Officer was not authorised to taxi the aircraft, it was towed to the gate for passenger disembarkation. The investigation found that the Captain had an undiagnosed medical condition which predisposed him towards the formation of blood clots in arteries and veins.)
- A320, vicinity London Heathrow UK, 2019 (On 23 September 2019, the flight crew of an Airbus A320 on approach to London Heathrow detected strong acrid fumes on the flight deck and after donning oxygen masks completed the approach and landing, exited the runway and shut down on a taxiway. After removing their masks, one pilot became incapacitated and the other unwell and both were taken to hospital. The other occupants, all unaffected, were disembarked to buses. The very comprehensive investigation was unable to establish the origin of the fumes but did identify a number of circumstantial factors which corresponded to those identified in previous similar events.)
- B733, en-route, northwest of Athens Greece, 2005 (On 14 August 2005, a Boeing 737-300 was released to service with the cabin pressurisation set to manual. This abnormal setting was not detected by the flight crew involved during standard checks. They took no corrective action after take-off when a cabin high altitude warning occurred. The crew lost consciousness as the aircraft climbed on autopilot and after eventual fuel exhaustion, the aircraft departed controlled flight and impacted terrain. The Investigation found that inadequate crew performance had occurred within a context of systemic organisational safety deficiencies at the Operator compounded by inadequate regulatory oversight.)
- B738, en-route, south east of Marseilles France, 2011 (On 6 July 2011 the First Officer of a Ryanair Boeing 737-800 was suddenly incapacitated during a passenger flight from Pisa to Las Palmas. The Captain declared a ‘medical emergency’ and identified the First Officer as the affected person before diverting uneventfully to Girona. The subsequent investigation focused particularly on the way the event was perceived as a specifically medical emergency rather than also being an operational emergency as well as on the operator procedures for the situation encountered.)
- B738, en-route, south west of Beirut Lebanon, 2010 (On 25 January 2010, a Boeing 737-800 being operated by Ethiopian Airlines on a scheduled passenger flight from Beirut to Addis Ababa in night IMC disappeared from ATC radar soon after departure from Runway 21 and was subsequently found to have impacted the sea in an unintentional out of control condition some five miles south west of the airport less than five minutes after getting airborne Impact resulted in the destruction of the aircraft and the death of all 90 occupants.)
- B738, vicinity Porto Portugal, 2015 (On 5 September 2015, a Boeing 737-800 was about to commence descent on a non-precision final approach at Porto in VMC when a green laser was directed at the aircraft. The Pilot Flying responded rapidly by shielding his eyes and was unaffected but the other pilot looked up, sustained flash blindness and "crew coordination was compromised". Subsequently, the approach became unstable and a go around to an uneventful approach to the reciprocal runway direction was completed. The subsequent Investigation noted the use of increasingly powerful green lasers in this way and that such use was not contrary to Portuguese law.)
- B744, vicinity Dubai UAE, 2010 (On 3 September 2010, a UPS Boeing 747-400 freighter flight crew became aware of a main deck cargo fire 22 minutes after take off from Dubai. An emergency was declared and an air turn back commenced but a rapid build up of smoke on the flight deck made it increasingly difficult to see on the flight deck and to control the aircraft. An unsuccessful attempt to land at Dubai was followed by complete loss of flight control authority due to fire damage and terrain impact followed. The fire was attributed to auto-ignition of undeclared Dangerous Goods originally loaded in Hong Kong.)
- B763, Atlanta GA, USA 2009 (On 19 October 2009, a Boeing 767-300 being operated by Delta Airlines on a scheduled passenger flight from Rio de Janeiro to Atlanta inadvertently made a landing at destination in night VMC on parallel taxiway ‘M’ instead of the intended and ATC-cleared landing runway 27R. None of the 194 occupants were injured and there was no damage to the aircraft or conflict with other traffic or vehicles. The third rostered crew member had become incapacitated en route with the consequence that neither of the other pilots had been able to take any in flight rest.)
- B763, en-route, Atlantic Ocean, 2008 (On 28 January 2008, the first officer on a B767, flying from Toronto to London, became incapacitated and the captain elected to divert to the nearest airport, Shannon, Ireland.)
- BA11, en-route, Didcot Oxfordshire UK, 1990 (On 10 June 1990, a BAC 1-11 operated by British Airways, during climb, experienced sudden explosive depressurisation which resulted in loss of the left hand windscreen. The commander was sucked in the windscreen aperture and was successfully secured by the cabin crew, while the first officer executed a safe landing.)
- BE20, vicinity Stapleford UK, 2015 (On 3 October 2015, the pilot of a Beech Super King Air on a business flight lost control in IMC shortly after take-off and the aircraft subsequently impacted terrain at high speed. The Investigation concluded on the balance of probabilities that pilot medical incapacitation was likely to have occurred. It was noted that the aircraft had not been fitted with TAWS nor was it required to be but it was found that alerting from such a system would have increased the chances of the only passenger, another professional pilot, successfully taking over and three corresponding Safety Recommendations were made.)
- Loss of Cabin Pressurisation
- Fire in the Air
- Accident and Serious Incident Reports: Crew Incapacitation
- Laser Interference in Aviation
- Food Poisoning (OGHFA SE)
- ICAO Doc 8984 "Manual of Civil Aviation Medicine", third edition 2012. Part 1, Chapter 3 concerns Flight Crew Incapacitation.
- Flight Crew Incapacitation, BEA France, Incidents in Air Transport No. 12, Feb 2011
- Diabetes mellitus and its effects on pilot performance and flight safety
- AviAtion LAser exposure seLf-Assessment (ALesA), UK CAA
- UK CAA CAP 1703: Aircrew guide to gastroenteritis, August 2018