Airworthiness Directive 2012-12-21
one-timeAirworthiness Directives; Eurocopter Deutschland GmbH Helicopters
What this AD requires
We are superseding an existing airworthiness directive (AD) for all Eurocopter Deutschland GmbH (ECD) Model MBB-BK 117 C-2 helicopters. That AD currently requires revising the "Emergency and Malfunction Procedures" and "Performance Data" sections of the Rotorcraft Flight Manual (RFM) by inserting three temporary pages into the RFM to alert pilots to monitor the power display when a generator is deactivated and provides procedures to prevent failure of the remaining generator. Before we issued that AD, the manufacturer developed a procedure to modify the two "After Junction Boxes" by removing a diode from each box, which provides terminating action for our AD requirements. These actions are intended to require implementing this terminating action to prevent an electrical power system failure and subsequent loss of control of the helicopter and revising the RFM accordingly, by removing the temporary pages inserted to comply with the superseded AD.
Which aircraft AD 2012-12-21 applies to
Applicability depends on the aircraft’s type certificate — check it against the specific tail.
Whether AD 2012-12-21 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.