Common medical causes of in-flight incapacitation amongst airline pilots in U.K were cardiovascular (heart attacks, rhythm disturbances) and neurological (epileptic seizures) . Another study in U.S. identified several causes of in-flight incapacitation. This included loss of consciousness; causes related to the gut viz., gallbladder stones, gastroenteritis or discomfort due to expansion of trapped intestinal gases; besides kidney stones and other neurological or cardiovascular causes . Invariably incapacitation caused by the ‘heart attack’ resulting in sudden death leads to fatal outcome in single cockpit operations  but the usefulness of minimal two crew operations in commercial aviation is more than evident in all the three cases of pilots’ death in flight enumerated above [1, 2, 3].
Evans et al., have recently published a study on the annual incapacitation rate, “irrespective of whether or not they were associated with flying” of the “class 1 medical certificate holder with a valid UK/JAR professional pilot’s license” in U.K. . The period of this study was c. 2004.
For the purpose of this study ‘incapacitation‘ was defined as “a medical event that resulted, or would have had the propensity to result, in an inability to act as flight crew for at least 10 min“; and ‘impairment‘ as “partial incapacitation associated with symptoms that resulted, or would have had the propensity to result, in a reduction of function or distraction from the flight crew task, but would be unlikely to have caused loss of control of an aircraft” .
There were a total of 36 episodes of incapacitation amongst professional pilots in U.K., as reported in this study . The commonest was 13 episodes related to cardiovascular causes including acute myocardial infarction (n=6), chest pain (n=2), arrhythmia (n=3), and pulmonary embolus (n=2). This was followed by 9 episodes of neurological causes including stroke (n=4), subarachnoid haemorrhage (n=1), epilepsy (n=2), migraine (n=1) and vestibular disturbance (n=1). There were 4 episodes of spontaneous pneumothorax, while gastrointestinal causes included gastric ulcer, perforated appendix, bowel obstruction, biliary colic, and syncope due to fluid loss during a severe episode of gastroenteritis. Interestingly there were 3 episodes of Panic attacks (twice in the same pilot) resulting in pilot incapacitation.
There were 76 events that resulted in impairment, with 20 of them being cardiovascular (angina (n=6), palpitations (n=6), severe chest pain (n=4), transient ischaemic attack (n=2), presyncope (n=1) and bradycardia (n=1). Three episodes of panic or anxiety attack were reported in flight associated situations, once in flight and twice during simulator training . It must be highlighted that 6 episodes out of 16 were attributed to psychiatric causes that occurred either in flight (crew or as passenger) or in simulator; with all of them being serious enough to lead to “suspension of license privileges” .
This study also elaborated the commonest causes of temporary unfitness amongst the class 1 medical certification holders (n=720) . Majority (18% each) of temporary unfitness was caused by either accidents or were musculoskeletal in nature; closely followed by cardiovascular (14%) and psychiatric (10%) causes. Other causes of temporary unfitness were gastrointestinal (8%), ear-nose-throat (6%), and genitourinary (4%). Pregnancy, neoplasm and neurologic causes were reported to be 3% each .
Acknowledgement Image courtesy Freedigitalphotos.net