FAA Orders 737 MAX Bear Strap Inspections

The FAA issued a final airworthiness directive on 3 August 2026 requiring operators to inspect the forward galley door bear strap area on certain Boeing 737-8, 737-9 and 737-8200 aircraft for cracking. The directive, designated AD 2026-15-11 and effective 10 September 2026, covers an estimated 471 US-registered aeroplanes and approximately 1,429 aircraft worldwide. No cracks have been found in any 737 MAX airframe to date, but the FAA determined the type is susceptible to the same cracking condition already observed on earlier-generation 737 variants.

What the directive says

AD 2026-15-11 requires compliance with Boeing Alert Requirements Bulletin 737-53A1408 RB, dated 20 December 2024. That bulletin specifies an external general visual inspection of the fuselage skin for any repair, followed by applicable on-condition actions. These on-condition actions include repetitive detailed inspections for cracking of the fuselage skin, repetitive external surface high-frequency eddy current (HFEC) inspections at certain fastener locations and along the edge of the door corner radius, repetitive external subsurface low-frequency eddy current (LFEC) inspections of the bear strap at certain fastener locations, and obtaining instructions from Boeing for alternative inspections or crack repair.

The FAA issued the directive under 14 CFR Part 39, the regulation governing airworthiness directives. The agency identified the unsafe condition as cracks in the fuselage skin and bear strap at the forward upper corner of the forward galley door cutout. According to the AD text, such cracks "may lead to the inability of the principal structural element to sustain limit loads and adversely affect the structural integrity of the airplane."

Bear straps explained

Bear straps are metal reinforcement sheets applied around door cutouts and emergency exits in the fuselage. They distribute structural loads around the opening and are common to many transport aircraft designs. The FAA first mandated bear strap crack inspections on 737 Classic variants in 2014. Boeing notified 737 Next Generation operators of the same issue in 2019 and provided inspection instructions, which the FAA mandated in 2021. The December 2024 Alert Requirements Bulletin extended the inspection programme to 737 MAX variants because they share a similar door cutout design and build process.

The FAA's final rule, published in the Federal Register on 6 August 2026, notes that 737 MAX aircraft are "likely susceptible to the same crack conditions" as their predecessors. The cracking mechanism stems from high operating stresses in the fuselage skin and bear strap due to stress concentration at the corner of the door cutout, which develops over repeated pressurisation cycles and flight hours.

A timeline built on earlier findings

The regulatory paper trail for this issue extends across multiple aircraft generations:

Date	Event
2014	FAA mandates bear strap crack inspections on 737 Classic variants
2019	Boeing notifies 737NG operators of the issue and provides inspection instructions
2021	FAA mandates 737NG bear strap inspections
25 November 2025	FAA publishes Notice of Proposed Rulemaking for 737 MAX inspections
20 December 2024	Boeing issues Alert Requirements Bulletin 737-53A1408 RB
3 August 2026	FAA issues final AD 2026-15-11
10 September 2026	AD effective date; compliance required

The proposed rule attracted public comments before finalisation. The FAA reviewed those comments and issued the final directive without substantive changes to the inspection requirements. The agency confirmed that the compliance times and procedures in the Boeing bulletin remain appropriate.

Operator responses

Southwest Airlines, one of the largest 737 MAX operators in the US fleet, told CBS News it was "reviewing" the airworthiness directive and would "accomplish the inspections on the affected airplanes according to the schedule specified by the FAA." United Airlines indicated it did not anticipate near-term operational disruption. A spokesperson said the carrier would accomplish inspections during heavy maintenance visits and that, given the current flight cycle counts on its oldest MAX airframes, the inspections would not fall due for some time.

Both statements are consistent with how Part 121 certificate holders typically manage fleet-wide ADs: the compliance schedule in the Boeing bulletin ties inspections to accumulated flight cycles, meaning newer airframes will not require inspection immediately. This allows operators to sequence the work into existing maintenance planning rather than grounding aircraft ahead of their next scheduled input.

What it means for maintenance planning

The AD introduces a new recurring inspection task into the 737 MAX maintenance programme. MRO organisations performing heavy checks on affected airframes will need to incorporate the HFEC and LFEC inspection procedures, which require specific non-destructive testing (NDT) equipment and qualified personnel. The FAA's cost estimate places the inspection work at approximately US$85 per labour hour, with up to 124 work-hours for the radius filler inspection and up to 244 work-hours for the crack inspection per aircraft, depending on findings.

For operators with large 737 MAX fleets, the cumulative labour demand across a compliance cycle could be significant, particularly when combined with other ongoing AD-driven inspections on the type. The repetitive nature of the on-condition actions means this is not a one-time inspection — aircraft cleared at one interval will require repeat inspections at the cycle thresholds defined in the Boeing bulletin.

A pattern of legacy fatigue issues

The bear strap directive is not an isolated event. It sits alongside a separate FAA airworthiness directive, AD 2026-13-03, effective 6 August 2026, which requires crack inspections on Boeing 747-8F freighter stringers and splice fittings. Both directives address structural fatigue conditions traced to similar design and manufacturing practices across Boeing programmes.

The 737 MAX has been under heightened FAA scrutiny since the January 2024 737-9 door-plug event, which prompted the agency to halt production expansion and increase factory and supplier oversight. The FAA's production-oversight framework, including its control of airworthiness certificate issuance for new MAX aircraft, remains in place. For background on the FAA's broader relationship with Boeing on certification authority, see our earlier coverage of how that authority was restored.

The bear strap AD also illustrates why production rate decisions matter beyond delivery numbers. As Boeing moves toward higher 737 production rates, the quality of door cutout assembly and shimming work becomes more consequential. Our analysis of the rate 47 production path noted that the FAA retains direct control over production expansion decisions — a framework within which structural ADs like this one serve as a feedback loop on manufacturing quality.

What to watch

Several milestones will determine the operational impact of AD 2026-15-11:

• Initial inspection findings: The first round of compliance inspections, particularly on higher-cycle 737 MAX airframes, will reveal whether the predicted cracking condition has begun to manifest in the MAX fleet. Early results will inform whether the FAA revises compliance thresholds.
• Boeing engineering changes: Boeing told FlightGlobal it is "conducting engineering analysis to identify root cause and is working through engineering changes that would prevent such cracking." A design fix would eventually reduce or eliminate the repetitive inspection burden, but any such change would require its own certification process.
• AMOC requests: The AD allows for alternative methods of compliance under 14 CFR 39.19. Operators may seek AMOC approval for modified inspection intervals or procedures, which could shift the maintenance planning picture.
• Interaction with future production decisions: Inspection findings will feed into the FAA's ongoing assessment of 737 production quality and its decisions on further rate increases.

The broader question is whether the bear strap cracking pattern — now spanning three 737 generations — will finally yield a design solution, or whether it will remain a managed inspection programme indefinitely. The FAA's willingness to mandate inspections before any MAX cracking has been observed suggests the agency is applying a more precautionary posture than it did with earlier variants. For operators, that means planning for recurring NDT work as a standing part of the 737 MAX maintenance programme.

Sources

• Federal Register: Airworthiness Directives; The Boeing Company Airplanes (AD 2026-15-11)
• AP News: FAA orders urgent inspections for 471 Boeing 737 Max jets
• FlightGlobal: FAA orders Boeing 737 Max inspections
• CBS News: FAA orders inspections of Boeing 737 Max jets

For more on airworthiness directive compliance, see the Flight Brief's coverage.

For more on MRO super-cycle, see the Flight Brief's coverage.