Airworthiness Directive · Amendment 39-16617 · Turbomeca Model Arriel 1E2, 1S, and 1S1 Turboshaft Engines
Turbomeca Model Arriel 1E2, 1S, and 1S1 Turboshaft Engines
This AD applies to Turbomeca Arriel 1E2, 1S, and 1S1 turboshaft engines that have incorporated Turbomeca Service Bulletin (SB) No. 292 73 0826, Version A, dated October 13, 2009, or incorporated Turbomeca Internal Consign No. 298468. These engines are installed on, but not limited to, Eurocopter Deutschland MBB BK117-C2 and BK117-C1, and Sikorsky S-76A series and S-76C series, helicopters.
This action supersedes emergency airworthiness directive (AD) 2011-05-51 that was sent previously to all known U.S. owners and operators of the products listed above. That AD requires inspecting the fuel ejector in the body of the fuel ejector assembly for proper installation by checking that the circlip is properly seated in its groove. That AD was prompted by three reports of incorrectly assembled low-pressure fuel system ejectors; with one of them resulting in an uncommanded engine in-flight shutdown. This AD requires the same actions and compliance times as the emergency AD, after receipt of the emergency AD, and expands the AD applicability by including helicopters having one or two affected engines and experiencing no starting difficulties. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
Comply with this AD within the compliance times specified, unless already done.
Inspect the fuel ejector in the body of the fuel ejector assembly for proper installation by checking that the circlip is properly seated in its groove. Use Paragraph 2.B of the Instructions to be Incorporated, of Turbomeca Mandatory Service Bulletin (MSB) No. A292 73 0834, Version B, dated February 8, 2011 to do the inspection. Inspect at the following compliance times:
(1) For helicopters having at least one of the two affected engines experiencing starting difficulties, inspect within 5 flight hours (FH) after receipt of emergency AD 2011-05-51 or after the effective date of this AD, whichever occurs first.
(2) For helicopters having only one affected engine, and experiencing starting difficulties in that engine, inspect within 20 FH after receipt of emergency AD 2011-05-51 or after the effective date of this AD, whichever occurs first.
(3) For helicopters having one or two affected engines and experiencing no starting difficulties, inspect within 100 FH after the effective date of this AD.
If you find a fuel ejector improperly installed in the body of the fuel ejector assembly, replace the fuel ejector assembly before further flight with a serviceable fuel ejector assembly.
For the purpose of this AD, starting difficulties occur when N1 stagnation or variations are encountered. During starting, N1 rise shall be continuous and linear up to ground idle.
(i) Inspections and replacements done using Turbomeca MSB No. A292 73 0834, Version A, dated February 4, 2011, or Turbomeca SB No. 292 73 0826, Version B, dated February 4, 2011, before the effective date of this AD, satisfy the requirements of this AD.
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.
