AD/GBK 117/21 - Pressure Altitude Limitation and Max N1 Check (Cth)

AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Eurocopter BK 117 Series Helicopters AD/GBK 117/21 Pressure Altitude Limitation 9/2008 and Max N1 Check

Applicability: EUROCOPTER DEUTSCHLAND MBB-BK 117 C-1 and C-2 helicopters except those aircraft on which both engines have been modified in accordance with Turboméca Modification TU358. Requirement: 1. Affix the selected placard and amend the Flight Manual (FLM) in accordance with the instructions of the referenced Alert Service Bulletin.

2. For helicopters that are about to perform starting, landing and hovering procedures in or out of ground effect at pressure altitudes above 10,000 feet and/or flights at pressure altitudes above 13,000 feet, accomplish the "MAX N1 CHECK" to establish the OEI rating of the engines in accordance with the instructions of the referenced Alert Service Bulletin.

3. Repeat the "MAX N1 CHECK" to establish the OEI rating of the engines in accordance with the instructions of the referenced Alert Service Bulletin.

4. If the OEI rating is not reached, only operations at pressure altitudes up to a maximum of 10,000 feet and mission flights at pressure altitudes up to a maximum of 13,000 feet may be conducted. Amend the placard and FLM accordingly.