Airworthiness Directive · Amendment 39-18373 · Airbus Helicopters Deutschland GmbH (Previously Eurocopter Deutschland GmbH) Helicopters
Airbus Helicopters Deutschland GmbH (Previously Eurocopter Deutschland GmbH) Helicopters
This AD applies to AHD Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, C-1, and C-2 helicopters, certificated in any category.
We are adopting a new airworthiness directive (AD) for Airbus Helicopters Deutschland GmbH (AHD) (previously Eurocopter Deutschland GmbH) Model MBB-BK 117 A-1, A-3, A-4, B-1, B-2, C-1, and C-2 helicopters. This AD requires an initial and recurring inspection of the N2 control arm and, depending on the outcome of the inspection, repairing or replacing the N2 control arm. This AD was prompted by a report of a heavily corroded and broken N2 control arm. The actions of this AD are intended to detect corrosion, a crack, or a scratch in the N2 control arm, which could lead to failure of the N2 control arm, a drop in rotor speed, and subsequent loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
For helicopters that have not reached 2 years from the date of first flight, within 1 year or before reaching 2 years from the date of first flight, whichever occurs first; and for helicopters that have reached or exceeded 2 years from the date of first flight, within 50 hours TIS:
(1) Visually inspect each N2 control arm for corrosion, a crack, and a scratch as depicted in Figure 1 of Eurocopter Alert Service Bulletin (ASB) MBB-BK117-60A-126 or ASB MBB-BK117 C-2-76A-005, both Revision 0, and both dated June 24, 2013, as applicable to your model helicopter.
(i) If an N2 control arm has corrosion or a scratch less than 0.5 millimeter (mm) (0.020 inch) in depth, before further flight, remove the corrosion and repair the scratch.
(ii) If an N2 control arm has any exfoliation corrosion, a crack, or has corrosion or a scratch 0.5 mm (0.020 inch) or greater in depth, before further flight, replace the N2 control arm.
(2) Thereafter, perform the requirements in paragraph (e)(1) of this AD at intervals not to exceed 12 months.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
