FAA issues final rule on fix for Boeing 747 crew seat malfunction

   

The Federal Aviation Administration (FAA) has superseded an airworthiness directive (AD) that addressed a fault with both pilots’ seats on Boeing 747 family aircraft, ranging from the 747-200 to the 747-8. The latest directive added inspections on previously omitted part numbers.

In the directive that the FAA published to the Federal Register on February 12, the regulator noted that the notice of proposed rulemaking (NPRM) that preceded the AD was prompted by reports of uncommanded movements of the captain and first officer’s seats.

The AD, which applies to 747-200, 747-300, 747-400, and 747-8 series aircraft, including passenger and cargo jets, aims to prevent uncommanded movements of both pilots’ seats.

“An uncommanded fore or aft seat movement during a critical part of a flight, such as takeoff or landing, could cause a flight control obstruction or unintended flight control input, which could result in the loss of the ability to control the airplane.”

The Air Line Pilots Association, International (ALPA) and UPS commented on the directive, with the former supporting the directive without change, while the latter provided editorial corrections. The FAA disagreed with all but one correction.

According to the FAA’s estimates, 162 747s registered in the US could be affected by the directive.

In terms of inspections, the regulator retained all three inspection actions from the now-superseded directive, which the FAA issued in December 2019, which includes one-time and repetitive checks of the horizontal movement system (HMS) of the pilots’ seats.

On-condition actions could include the adjustment of the control lever cable, the overhaul of the HMS, inspection of each seat’s fore/aft and vertical manual control levers, installation of serviceable seats, clearing foreign object debris (FOD), replacement of the horizontal actuator, and an operational test of the adjusted control level cable.

The directive’s effective date is March 19, 2025.

In the past few years, the FAA has issued multiple directives addressing seat issues with Boeing aircraft, including an AD for the 767-200, 767-300, and 767F, due to reports “of uncommanded fore and aft movement of the Captain's and First Officer's seats.”

However, the most high-profile directive was issued after a LATAM Airlines Boeing 787-9 was involved in an incident when the aircraft suddenly lost altitude while flying from Sydney Airport (SYD) to Auckland Airport (AKL) on its way to Santiago Arturo Merino Benítez International Airport (SCL).

Following the event, which resulted in more than 50 injuries onboard the 787-9, the FAA issued an AD to mandate inspections of both pilots’ seats in August 2024 for missing or cracked rotor switch caps and cracked or non-functional switch cover assemblies.

At the time, the FAA warned that in addition to the LATAM Airlines event, Boeing reported four additional instances of uncommanded movement of the pilots’ seats, with the most recent event happening in June 2024.