Airworthiness Directive 2026-09521
one-timeAirworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters
What this AD requires
The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 C-2 and MBB- BK 117 D-2 helicopters. This AD was prompted by a determination that a certain part-numbered standard MS18027 type hook may be subject to localized yielding in the mating threads when assembled to higher assembly torques. This AD requires modifying and re-identifying the affected part or replacing the affected part with a serviceable part. This AD also prohibits installing an affected part on any helicopter unless certain requirements are met. The FAA is issuing this AD to address the unsafe condition on these products.
Which aircraft AD 2026-09521 applies to
Whether AD 2026-09521 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.