CTHIn ForceLegislation
AD/GBK 117/21 - Pressure Altitude Limitation and Max N1 Check
Eurocopter BK 117 Series HelicoptersEurocopter BK 117 Series Helicopters
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Eurocopter BK 117 Series Helicopters
| AD/GBK 117/21 | Pressure Altitude Limitationand Max N1 Check | 9/2008 |
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| 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. |
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| 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.5. Repeat the “MAX N1 CHECK” to establish the OEI rating of the engines in accordance with the instructions of the referenced Alert Service Bulletin.6. Remove the placard and FLM changes from the helicopter.Once modification TU358 is incorporated into both Fuel Control Units (FCU)’s the “MAX N1 CHECK” is no longer required.7. Do not install a spare FCU on any helicopter as a replacement part unless it has been modified in accordance with Turboméca modification TU358.Eurocopter Deutschland Alert Service Bulletin (ASB) No. ASB-MBB-BK117-60-121 Revision 4 pertains to the requirements of this AD. The use of later approved revisions of these documents is acceptable for compliance with the requirements of this AD. |
| Note: EASA AD 2008-0061 dated 27 March 2008 refers. | |
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| Compliance: | 1. Within 30 days after the effective date of this AD, unless previously accomplished.2. Before the next such mission after the effective date of this AD.3. Within 600 Flight Hours (FH) after the effective date of this AD and thereafter at intervals not to exceed 600 FH.4. From the effective date of this AD.5. When, after failing to reach the OEI rating, and either the engine, the FCU, engine module 2 and/or engine module 3 is replaced.6. After modification of both FCUs in accordance with Turboméca modification TU358.7. After 10 April 2009. |