AD 2021-02-11
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Airbus | Helicopters Deutschland GmbH | Airworthiness Directives; Airbus Helicopters Deutschland GmbH Helicopters |
| aircraft | Bell | Various | Airworthiness Directives; Airbus Helicopters Deutschland GmbH Helicopters |
Unsafe Condition
a crack in a tail gearbox (TGB) bellcrank attachment arm, which could result in disconnection of the bellcrank attachment arm from the TGB and subsequent loss of control of the helicopter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 100 hours time-in-service, remove the surface coating from the TGB bellcrank attachment arm and using a 5X or higher power magnifying glass, dye-penetrant inspect the TGB arm for a crack and for any dent, nick, and scratch. If there is a crack, before further flight, replace the TGB. If there is a dent, a nick, or a scratch, before further flight, remove the surface material up to 0.2 mm using 80-grit abrasive paper and repeat the dye penetrant inspection. If there is a crack or if the damage cannot be removed, before further flight, replace the TGB. If there is no crack and no dent, nick, or scratch, before further flight, finish the surface with 600-grit or finer abrasive paper.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 100 hours time-in-service
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Airbus Helicopters Deutschland GmbH Model MBB-BK117 A-1, MBB-BK117 A-3, MBB-BK117 A-4, MBB-BK117 B-1, MBB-BK117 B-2, MBB-BK117 C-1, and MBB-BK117 C-2 helicopters, certificated in any category.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
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