EASA AD CF-2023-29
Nacelles / Pylons — Pylon Aft Engine Mount Attachment Bolts — Discarding and Replacement of Bolts not Performed
Summary
The Airworthiness Directive CF-2023-29 addresses an issue with Bombardier Inc. model BD-100-1A10 aeroplanes, including Challenger 300 and Challenger 350 variants. It concerns the incorrect part number referenced in the Time Limits/Maintenance Check manual for the pylon aft engine mount attachment bolts, which could lead to failure if not properly replaced. This directive mandates the correct discard and replacement of these bolts to ensure continued airworthiness.
What Changed
This new Airworthiness Directive introduces a requirement to perform the revised Time Limits/Maintenance Check Task 54-51-00-111* using the correct part number MS21250-07 for the aft engine mount attachment bolts. It corrects the previously misleading part number MS21250-7 in the maintenance documentation and requires operators to follow updated manuals issued by Bombardier.
Why It Matters
The directive is critical because failure to replace the aft engine mount attachment bolts with the correct parts could result in engine detachment, posing a catastrophic risk. Aviation professionals, including operators and maintenance organizations, must ensure compliance to maintain aircraft safety and regulatory conformity. It also prevents potential operational disruptions caused by unaddressed maintenance errors.
What To Do
Operators of Bombardier BD-100-1A10 aircraft must perform Task 54-51-00-111* as specified in the revised TLMC manuals within 60 days of the directive's effective date. They should use the updated manuals Revision 23 for Challenger 300 and Revision 13 for Challenger 350, ensuring the correct bolts are discarded and replaced. Compliance with later approved revisions of the TLMC manuals is also acceptable.
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