Statistics from Altmetric.com
Editor,—The editorial “Flying after heart surgery”,1 is timely and focuses on an important aspect of rehabilitation. One might, however, question the validity of the statement that “Pilots may see cardiac surgery as their only hope...”. Furthermore, in attempting to explain “the 1% rule”, the defining point between professional fitness to fly on multicrew operations and permanent unfitness for duty, the authors' statements need some clarification.
The 1% rule2 requires that the cardiovascular mortality rate of an airman should not exceed 1% per annum, or approximately one event/one million hours. This attrition is approximately that of a 65 year old man in northern Europe and will be encumbered by additional non-fatal co-morbid, but potentially incapacitating, events. It does not rely, as Treasure and Janvrin have stated,1 on the impossible incapacitation rate of one event in 1 000 000 000 hours. This figure is the aviation industry target for the “very remote” possibility of an unpredicted (that is, mechanical) catastrophe leading to a fatal accident,3 and is also the target multicrew fatal accident rate attributable to incapacitation of one of the pilots.3 Employing the 1% rule, and making the assumption that only 10% of the envelope of a flight of average duration (100 minutes) is vulnerable with a 1% chance of an event during the vulnerable period leading to an accident,4 the probability of a multicrew accident because of a cardiovascular cause is in the order of 1 in 1 000 000 000 hours, a target the industry is on course to achieve.
The most recent and currently used protocols for recertification following cardiac surgery, which are published in the Joint Aviation Requirements—Flight Crew Licensing Part 3 (medical),5 for Europe, require a post index event (surgery, angioplasty, myocardial infarction) delay of six months before recertification can be considered. This differs from the figures derived from the older publications that are quoted by your contributors. Those requiring the text of the JAR-MED, or advice, may write to the Chief Medical Officer, Medical Division, Civil Aviation Authority, Gatwick, West Sussex RH6 0YR, or to the Joint Aviation Authorities, PO Box 3000, 2130KA, Hoofdorp, Netherlands. An up to date bibliography on the subject (not cited) is included in the Second European Workshop in Aviation Cardiology.6
The letter was shown to the authors who reply as follows:
Our editorial in Heartdoes discuss an aspect of rehabilitation after cardiac surgery, albeit a very narrow one. Pilots often do see cardiac surgery as their only hope of regaining a licence to fly, and in this context we consider our statements to be valid.
We are not sure that Professor Joy's clarification of the 1% rule adds much to what we wrote on a “need to know” basis for cardiac surgeons. Both he and we state the same thing. To the travelling public, a reassuringly small chance (1 in 1 000 000 000 hours of flying) of a pilot's incapacitation leading to a fatal aircraft accident is met by that pilot (and the co-pilot) having less than a 1% risk of a myocardial event in a year.
We then set out the post surgery criteria that must be achieved to meet that risk. These are the criteria published in the current European Joint Aviation Requirements,1-1 which states that “. . .subjects may be considered for recertification [after coronary artery surgery] not sooner than nine months after surgery . . .”.
As a footnote, both Professor Joy and ourselves serve on the Civil Aviation Authority Medical Advisory Panel. This might indicate to your readers that reaching a panel consensus about a pilot's fitness to fly is seldom easy.