The Federal Aviation Administration (FAA) has proposed mandatory inspections of some Boeing 737 MAX aircraft after incorrectly installed bearings were identified in part of the mechanical flight-control system.
The proposed airworthiness directive covers certain 737 MAX 8, MAX 9 and MAX 8-200 aircraft identified by Boeing. The FAA estimates that 95 airplanes registered in the United States would be affected, although the figure does not represent the total number of potentially affected aircraft worldwide.
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The issue involves bearings installed in the elevator buss assembly, which forms part of the mechanical system connecting the pilots’ control columns with the elevators used to control aircraft pitch.
According to the FAA, some bearings may have been improperly installed during production, including without the required sealant. The condition can lead to cracks in the bearings and their housings, followed by premature failure of the elevator buss assembly crank arms.
The regulator said the condition, if not addressed, could affect elevator pitch control and continued safe flight and landing.
Inspections could lead to complete assembly replacement
Under the proposed directive, operators would have to conduct detailed inspections of the affected bearings and housings for cracks and verify whether sealant was properly applied.
Corrective work would depend on the inspection results. It could include load testing, replacement of individual bearings, repairs to affected areas or replacement of the complete elevator buss assembly.
The FAA estimates the initial inspection would require 23 work hours and cost about US$1,955 per aircraft. For the 95 US-registered airplanes, the estimated inspection cost totals US$185,725.
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September 23, 2026
September 23, 2026
Costs would rise substantially for aircraft requiring corrective work. Replacing individual bearings is estimated at between US$1,105 and US$1,809, depending on the component, while replacement of an entire elevator buss assembly could cost approximately US$98,500 per aircraft.
The FAA said it cannot estimate how many airplanes will require repairs. Some or all of the costs could also be covered by Boeing under warranty.
Boeing issued bulletin in December
The proposed requirements are based on Boeing Alert Requirements Bulletin 737-27A1331 RB, dated December 17, 2025. After reviewing the issue, the FAA determined that the unsafe condition is likely to exist or develop in other aircraft of the same type design.
The proposal does not affect every 737 MAX. Applicability is limited to aircraft identified by Boeing in the requirements bulletin, and the FAA's count of 95 covers only airplanes on the US registry.
The rule is also not yet mandatory. The FAA published it as a notice of proposed rulemaking on September 21 and will accept comments through November 5. Requirements could change before the agency issues a final airworthiness directive.
