Worn-out latch springs could cause the pilot seats on some Dassault Falcons to slide aft and the pilot or copilot to lose contact with the flight controls, according to an FAA Airworthiness Directive issued yesterday. The AD affects Falcon 900/900EXs and 2000/2000EXs equipped with Sicma 132- or 142-series pilot and copilot seats with spring P/Ns 132100-19 and/or 147100-19.

According to the FAA, there has been a documented case of a copilot’s seat sliding aft in a Falcon on rotation due to fatigued springs. “The results of the investigations concluded that one spring of the seat-locking system was broken and the other was weak. The root cause was determined to be fatigue wear. As springs accumulate cycles in service, they become increasingly exposed to the risk of unnoticed degradation or rupture,” the AD notes.

This AD, which affects 528 U.S.-registered airplanes, requires the springs to be replaced within nine months of the June 2 effective date for affected Falcons that are more than 74 months old or have more than 3,750 total flight cycles. It also requires the springs to be replaced thereafter at intervals not to exceed 78 months or 3,750 flight cycles, whichever occurs first.

The issue might not be limited to Falcon 900s and 2000s, the FAA noted. “If we determine that an unsafe condition exists on other airplane models, we might consider further rulemaking on this issue.”