In-flight Pilot Incapacitation (OGHFA SE)

In-flight Pilot Incapacitation (OGHFA SE)

The Incident as a Situational example

You are first officer on a transcontinental flight. Just prior to departure, the captain says he isn’t feeling fully fit but is well enough to fly. There is no problem up to and during cruise, and you start the descent early in the approach with sunrise just appearing. You are cleared through 10,000 ft, engine and wing anti-ice are turned on as the airplane enters clouds. The captain, as pilot flying (PF), selects anti-icing “on” appropriately, and the airplane is cleared for further descent, autopilot on, speed still at 250 kt. Passing through 8,000 ft, the captain asks you to go on the intercom to request that the cabin be prepared for landing.

Some three minutes after completing this call, you notice the aircraft is passing the final fix on the flight management system (FMS). Following this, you propose to extend the outer marker. At that moment, ATC orders you to turn to a heading of 150 degrees. This is not acknowledged by the captain. Looking at him, you notice he is staring straight ahead as if reflecting whether the heading was appropriate. Upon asking about his intention to turn, you become aware that he has his hand on the airspeed knob. He is quick to correct after you speak about this hesitation and selects a heading of 140 degrees.

What’s your reaction to your captain’s incorrect entry?

You challenge this by asking whether he wanted 140 or 150 degrees. ATC then gives you a turn to 160 degrees, but the captain does not initially react, and then experiences a clear seizure. Starting to shake with his upper body going limp, his right leg goes stiff and pushes the rudder. This causes the autopilot to disconnect.

Considering your captain‘s condition, what’s your next move?

You take control of the airplane. The captain puts in right aileron, which you counter to keep the wings level. He seems semi-conscious and incoherent, so you call the flight attendant for assistance.

Arriving in the cockpit, the flight attendant is not able to get the captain out of his seat. You make a call to request medical assistance on board. Two doctors volunteer to help. When they enter the cockpit, the captain is bleeding profusely from biting his tongue, shaking and foaming at the mouth. He is finally removed from his seat and laid on his back on the cockpit floor. His legs are extended forward between the left side of the pedestal and the right side of his seat with his feet near the yoke. Both doctors start Cardio Pulmonary Resuscitation (CPR) as he stops breathing. As a result the captain regains consciousness but remains incoherent and starts kicking the yoke again with his right foot.

Each time you succeed in reconnecting the autopilot, the captain kicks the yoke and disconnects it. The airplane is now between 7,000 and 6,000 ft, sometimes yawing with right banks of 15 to 20 degrees and fishtailing.

What do you do next?

You order the captain to be moved away from the yoke to stop the interference and allow you to resume use of the autopilot.

You declare an emergency, advising ATC that the captain is incapacitated. You aim for a straight-in approach. However, being above the glide slope, you use the vertical speed mode to try to intercept the slope. Having difficulties, you disconnect both autopilot and autothrottles to fly the approach manually using the flight director. The ceiling is 1,000 to 1,200 ft with a visibility of 10 miles or better, wind is 020 at 12 kt. The landing is uneventful, but you have to first bring the aircraft to a complete stop and change seats to clear the runway. Even during taxiing, the captain tries to get into the left seat and has to be restrained.

Data, Discussion and Human Factors

A pilot survey indicated that almost one-third of all pilots who responded had experienced incapacitation requiring another crewmember to take over their duties, with safety being threatened in 3 percent of cases. To process the data in such a context means establishing whether there can be a rationale for a “fit to fly” requirement.

Types of Incapacitation

The U.S. Federal Aviation Administration (FAA) Aeromedical Institute in Oklahoma City studied in-flight medical incapacitations and impairments in U.S. airline pilots from 1993 through 1998. It defined in-flight medical incapacitation as a condition in which a flight crewmember was unable to perform any flight duties and impairment as a condition in which a crewmember could perform limited flight duties such as reading checklists and making radio calls even though performance may have been degraded.

It found 39 incapacitations and 11 impairments aboard 47 aircraft over this six-year period with serious impacts on flight safety in seven flights, of which two resulted in non-fatal accidents The average age was 47 years for incapacitations and 43.3 for impairments with respective in-flight event rates of 0.045 per 100,000 flying hours and 0.013 per 100,000 flying hours. The probability that these events would end up in an accident was calculated at 0.04. Incapacitations significantly increased with age with more serious categories in the older age groups. In this study most frequent categories were loss of consciousness (9), gastrointestinal (6), neurological (6), cardiac (5) and urological (3).

In general, the various categories of incapacitation are loss of consciousness, cardiovascular, neurological, urological and gastrointestinal disorders. However, other less-frequent problems include respiratory, reaction to medications, diabetes, hemiparetic and epileptic seizures, earache due to blocked ears, traumatic or infected injury, faintness or general weakness and alcohol withdrawal syndromes.

Typical conditions for impairment pertain to food or carbon dioxide poisoning, nausea, baro sinusitis, vomiting and indigestion, viral gastroenteritis, vasovagal responses due to viral infection, the use of monovision contact lenses, fatigue and kidney stones.

The U.K. Civil Aviation Authority (CAA) said 49 cases of incapacitations occurred from 1992 to 1997 on public transport aircraft, with 38 of those in two-crew cockpits and 27 related to nausea and gastric troubles.

Prevention Strategies and Lines of Defense

The initial signs of crew incapacitation can be very subtle and may not be immediately obvious to other crewmembers.

Any crewmember feeling unwell prior to a flight or in flight should immediately report it so as not to compromise flight safety. It is clear that there are thresholds before a human being contemplates doing this. However, we should bear in mind that flight safety can be compromised if we don’t speak up.

In the event of crewmember illness in flight, it is up to the Captain or to the most senior cockpit crewmember to take responsibility and decide if an immediate landing is to be made. In the event of a crewmember or a number of crewmembers indicating symptoms of food poisoning, the Captain should take into account the possibility of a common cause that may produce further crew incapacitation.

If, due to incapacitation, the crew complement is reduced below the minimum for the aircraft, a PAN call must be made.

Even though two-crew aircraft were certificated for temporary single-pilot operations, the remaining pilot is left in an abnormal and unusual situation where workload is increased with little or no back-up of safety on critical items and increased vulnerability to errors or rapidly developing situations.

Here are some lines of defense:

  • The remaining pilot must assume or maintain control
  • Establish a safe flight profile and engage the autopilot; use all possible automation
  • Obtain cabin crew assistance
  • Inform ATC
  • If on an extended-range twin-engine operations (ETOPS) flight, the remaining pilot or PIC must assess whether to continue the flight, return to the departure airport or divert. The decision is based on:
    • Weather conditions at the destination or alternate
    • Reduction of flight time if diverting
    • Workload involved in single-pilot operation
    • Familiarity with the alternate
    • Condition of the incapacitated pilot
    • Availability of medical assistance
    • Overall safety of the flight
  • Arrange medical assistance upon arrival
  • Brief a cabin crew member to assist if required
  • Complete the approach and landing using the autopilot as much as possible
  • A partially incapacitated pilot should not be allowed to participate in the subsequent operation of the aircraft, as judgment may be impaired
  • After landing, seek immediate medical assistance

Summary and Key Points

Descending through 8,000 ft in preparation for landing, the captain as PF did not respond to an ATC heading change. When challenged by the first officer, he did not respond because he had had a seizure. The first officer subsequently did an excellent job in response to the captain's condition, delegating to appropriate people and handling flight duties to ensure a safe and uneventful landing.


Incapacitation of a crewmember is defined as “any condition which affects the health of a crewmember during the performance of duties which renders him or her incapable of performing the assigned duties.” Incapacitation is a real air safety hazard that occurs more frequently than many other emergencies in routine aviation training.

  • It can manifest itself in a variety of ways ranging from obvious sudden death to subtle, partial loss of function, not preceded by any warning. A partial incapacitation may be much more subtle to detect than a total one.
  • This type of incident can always occur on a flight, not only in cruise and not just by loss of consciousness. Removing a crewmember from his seat can be a difficult task.
  • It can be rather traumatic for the crew involved, and it can also be unsettling for the airline itself. A mature organization will neither disguise nor hide the event.
  • Discretionary choice of restaurant and different meals among crew may help prevent the consequences of food poisoning.


Early recognition of incapacitation is essential:

  • Routine monitoring and cross-checking of flight instruments, especially during critical phases of flight.
  • Flight crewmembers should be alert to subtle incapacitation:
    • If a crewmember does not respond appropriately to two verbal communications, or
    • If a crewmember does not respond to a verbal communication associated with a significant deviation from a standard flight profile
  • If you don’t feel well, say so and let the other pilot fly
  • Other symptoms of the beginning of incapacitation are:
    • Incoherent speech
    • Strange behavior
    • Irregular breathing
    • Pale fixed facial expression
    • Jerky motions that are either delayed or too rapid


The following summarizes the actions to recover from detected incapacitation:

  • The fit pilot must assume control and return the aircraft to a safe flight path, announce “I have control” and engage the autopilot
  • The fit pilot must take whatever steps are possible to ensure that the incapacitated pilot cannot interfere with the handling of the aircraft. This may involve cabin crew to restrain the incapacitated pilot.
  • If the cockpit door is locked, the assisting cabin crewmember should to unlock it.
  • The fit pilot must land as soon as practicable considering all pertinent factors
  • Arrange medical assistance after landing, giving as many relevant details about the condition of the crewmember as possible.

Associated OGHFA Material

Briefing Notes:


Situational Example:

Further Reading

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