AD 2013-12-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Eurocopter | Deutschland GmbH | Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters |
Unsafe Condition
Failure of a bevel gear, failure of the tail rotor intermediate gear box (IGB), 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
Determine if a bevel gear with a serial number listed in Table 1 of Eurocopter Alert Service Bulletin MBB BK117 C-2-04A-005, Revision 2, is installed in the IGB. If such a bevel gear is installed, record its reduced life limit on the component history card or equivalent record. If the bevel gear's life limit has been reached or exceeded, replace it with an airworthy bevel gear before further flight. Revise the Airworthiness Limitations section of the maintenance manual to reflect the reduced retirement life for affected bevel gears.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 30 days
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Affected Aircraft
Eurocopter Deutschland GmbH Model MBB-BK 117 C-2 helicopters with bevel gear, part number 4639 310 065, installed in the tail rotor intermediate gear box (IGB), part number 4639 002 007.
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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