FAA Proposes New Airworthiness Directive for Textron Aviation Model 402C and 414A Engine Beam Cracking

The FAA has issued a Notice of Proposed Rulemaking (NPRM) to supersede Airworthiness Directive (AD) 2015-07-03, which applies to certain Textron Aviation, Inc. Model 402C and 414A airplanes, a type certificate previously held by Cessna Aircraft Company. Since AD 2015-07-03 was issued, additional reports have emerged of cracking and multi-site cracking in hard-to-access areas of engine beams on these aircraft. Investigation determined that current engine beam inspection methods are insufficient and that a life-limit is needed for certain affected engine beams, prompting Textron to publish updated supplemental inspection material for both models.

The proposed AD would retain the repetitive inspection requirements from AD 2015-07-03 and add new requirements: repetitive inspections for cracks using visual, eddy current, and X-ray methods, applicable on-condition actions, and a new life-limit for affected engine beams with mandatory replacement once that limit is reached. The FAA states that failure to address this condition could result in engine separation, loss of power, and loss of control of the airplane.

The FAA estimates the proposed AD would affect 476 U.S.-registered airplanes. Estimated per-aircraft compliance costs include airplane preparation at $255 (3 work-hours at $85/hour), visual inspection at $85 (1 work-hour at $85/hour), eddy current inspection at $600 (1 contracted work-hour at $600/hour), and X-ray inspection at $1,080 (8 work-hours at $85/hour plus $400 in parts). Total estimated costs across U.S. operators range from approximately $40,460 for visual inspections to $514,080 for X-ray inspections, with full engine beam replacement estimated at $51,643 per aircraft, including $29,580 in labor. The NPRM is scheduled for publication in the Federal Register on September 23, 2026, under FAA Docket No. FAA-2026-8818, Project Identifier AD-2025-01766-A.

This case belongs to a familiar regulatory pattern: an inspection-only AD is superseded once continued operation surfaces cracking that the original method could not reliably catch, and the fix shifts from periodic checking to a hard life-limit with mandatory part replacement. For owners of aging piston twins like the 402C and 414A, that shift changes the economics of keeping an airframe flying, since a life-limited structural component eventually forces a defined-cost replacement rather than an open-ended inspection cycle.

The piston-twin segment generally absorbs these costs unevenly: aircraft already near the proposed life-limit face replacement sooner, while newer airframes in the fleet may only carry the added inspection burden for years before the limit becomes relevant. The layered inspection regime proposed here, visual plus eddy current plus X-ray, also reflects how regulators respond when a single method proves insufficient for hard-to-access structure.

What happens next depends on the comment period following the September 23, 2026 Federal Register publication, where operators and Textron can respond to the proposed life-limit and inspection intervals before the AD is finalized.