Aeromedical Concerns About Extended Minimum Crew Operations

The aviation industry is exploring possibilities to operate extended long-haul flights with two pilots in the cockpit during critical flight phases and a single pilot flying during cruise flight while the other pilot is sleeping. This Extended Minimum Crew Operations (eMCO) concept raises important aeromedical concerns: 1) a two-pilot cockpit is considered a main safety risk-mitigating factor and eMCO would therefore necessitate a new aeromedical risk assessment concept; 2) sensors and algorithms for monitoring physical and/or cognitive incapacitation are not available or insufficiently reliable; 3) scientific data of augmented long-haul flights is not valid for predicting effects of monotony and boredom or in-flight sleep and sleep inertia on alertness during eMCO cruise-flight; and 4) medical conditions regarding urination, defecation, or menstruation may cause an unscheduled visit to the toilet of the single pilot flying during cruise flight, who then has to request the resting pilot to take over the controls.

Simons R, Maher D, Vermeiren R, Wagstaff AS. Aeromedical concerns about extended minimum crew operations. Aerosp Med Hum Perform. 2025; 96(7):590–592.