AD 2021-10-23
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Airbus | Various | Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters |
Unsafe Condition
A Ti-bolt with hydrogen embrittlement could result in failure of the tail rotor ball bearing control Ti-bolt and subsequent loss of tail rotor control.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove any Ti-bolt part number EN3740-060022F marked with manufacturer monogram ``D'' or with an illegible manufacturer monogram, located on the aft connection of the tail rotor ball bearing rod end (item 5) and at the input lever (item 2) as shown in Figure 1 to Airbus Helicopters Alert Service Bulletin No. ASB MBB-BK117 D-2-00A-001, Revision 1, dated October 16, 2019, from service. Do not install a Ti-bolt identified in paragraph (c) of this AD on the aft connection of the tail rotor ball bearing control of any helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 50 hours time-in-service or 3 months, whichever occurs first.
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Affected Aircraft
Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 D-2 helicopters, certificated in any category, with a Titanium (Ti) bolt part number EN3740-060022F marked with manufacturer monogram ``D'' or with an illegible manufacturer monogram, installed on the aft connection of the tail rotor ball bearing control.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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