Printed headline: Check Yourself
A new NTSB report detailing a 2016 incident involving an improperly closed fan cowl door (FCD), provides another example of what operators have labelled a “recurring human factors issue.”
In September 2016, an Aruba-bound Airbus A320-200 circled back to Miami after the outboard FCD separated, damaging the engine, landing gear and fuselage. The safety board concluded that the door was improperly latched after a routine maintenance check.
Since 1992, the A320 family has experienced more than 40 similar incidents, resulting in a long list of regulatory actions.
In 2000 and 2001, the French civil aviation authority issued a set of rules mandating lock improvements and hold-open devices to combat non-detection of improperlyclosed cowl doors. A subsequent European Aviation Safety Agency (EASA) directive deemed those safety measures inadequate and prescribed additional remedies, including installation of new front latch and key assemblies. The mandate necessitates confirmation that the FCD key is properly stowed in the flight deck as part of the pre-flight inspection.
The FAA’s adoption of the EASA airworthiness directive—which comes with a price tag of $5.6 million for U.S. operators—was met with resistance. Commenters deemed the requirement overly prescriptive and inadequate for addressing the root cause: human error.
Airlines argued that design changes historically have proven ineffective in deterring human error, compared to other changes, such as dual inspection sign-offs. Instead, the introduction of further pieces of equipment, theymaintained, could lead to other operational complications, and “impose an unnecessary financial and maintenance burden on operators that have proactively implemented alternate procedures.”
At the time of the Flight AG820 incident, Aruba Airlines was in the process of modifying its fleet to comply with the EASA front latch and key assembly requirements. Since then, only Bangkok Airways experienced a similar incident when on July 25, 2017, both cowl doors on an A320 detached during takeoff.