The US FAA wants operators of Airbus A319 and Bombardier CRJ100/200 aircraft to develop type-specific training programmes to help mechanics and pilots verify that engine-fan cowls are properly latched before flight.
The Information for Operators note, published earlier this week, follows numerous incidents where unlatched covers have separated from the aircraft in flight or on the ground.
According to the FAA, there have been 15 such events involving Airbus single-aisle aircraft since 1992 and 33 incidents involving the CRJ models since 2001, including six cases in 2007.
"Despite the release of an FAA airworthiness directive (AD) for Airbus single-aisle airplanes and numerous bulletins for Airbus single-aisle and Bombardier CL-600-2B19 (CRJ 100/200) model airplanes, engine-fan cowl separations have continued to occur," the agency writes.
The FAA is recommending that carriers operating the aircraft "develop a training program for maintenance personnel and flight crews on inspection procedures to verify that the engine-fan's cowl is latched".
The agency is also asking that the carriers revise procedures to require maintenance crews to inform flight crews when engine-fan cowls have been opened before flight.