EASA AD US-2025-04-02
[Correction] Powerplant - Fan Cowl Support Beam Hinge Fittings - Replacement / Radial Restraint Assembly - Modification / External Doubler at Starter Vent - Installation
Summary
Correction to Airworthiness Directive 2025-04-02 issued by the Federal Aviation Administration (FAA) addresses The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. The directive involves replacement of fasteners on fan cowl support beam hinge fittings, modification of the radial restraint assembly, and installation of an external doubler at the starter vent or optionally installing a serviceable fan cowl. It also requires revising maintenance programs to incorporate new airworthiness limitations related to fan blade out conditions and engine nacelle maintenance errors.
What Changed
This correction fixes errors in the originally published AD regarding incorrect service information references and dates within the regulatory text. Specifically, it corrects the referenced Boeing and Collins Aerospace service bulletins and updates the effective dates for certain airworthiness limitations from 2018 and 2019 to 2028 and 2029 respectively. The correction ensures accurate compliance instructions without changing the original AD's requirements or effective date.
Why It Matters
Accurate service bulletin references and correct compliance dates are critical for operators and maintenance personnel to properly implement required modifications and inspections. This correction prevents confusion and potential non-compliance that could compromise safety by ensuring that the fan cowl and engine nacelle modifications are performed correctly and on time. It supports continued airworthiness by addressing risks associated with fan blade out events that could lead to structural damage or rapid decompression.
What To Do
Operators of affected Boeing 737 models must comply with the corrected AD by April 8, 2025, performing the specified replacement, modification, and installation actions as detailed in the corrected Boeing Special Attention Requirements Bulletin 737-71-1937 RB, Revision 1. Maintenance programs must be updated to include the revised airworthiness limitations with corrected dates. Any repairs requiring Boeing or Collins Aerospace approval must be done before further flight using FAA-approved methods.