Airworthiness Directive · Amendment 39-17015 · Turbomeca S.A. Turboshaft Engines
Turbomeca S.A. Turboshaft Engines
This AD applies to Turbomeca S.A. Arrius 2F turboshaft engines with right-hand (RH) rear half-wall, part number (P/N) 0319 99 824 0, installed.
We are superseding an existing airworthiness directive (AD) for Turbomeca S.A. Arrius 2F turboshaft engines with P3 air pipe (first section) part number (P/N) 0 319 71 918 0, installed. That AD currently requires inspections of the P3 air pipe (first section) and right-hand (RH) rear half-wall for proper clearance and readjustment of the pipe if necessary. This new AD requires the same inspections for installed engines, eliminates readjusting of the P3 air pipe (first section), requires replacement of the RH rear half-wall under certain conditions, and adds an optional terminating action. This AD was prompted by Turbomeca determining that the clearance between the P3 air pipe (first section) and the RH rear half-wall might change during installation of the engine on the helicopter. We are issuing this AD to prevent an uncommanded power loss to flight idle, which could result in an emergency autorotation landing or accident.
(1) For installed engines, within 100 engine hours (EH) after the effective date of this AD:
(i) Inspect the clearance between the P3 air pipe (first section) and the RH rear half-wall for sufficient clearance (0.5 mm or more).
(ii) Use paragraph 2.B.(1) of Turbomeca Mandatory Service Bulletin (MSB) No. 319 75 4810, Version B, dated January 25, 2011 to do the inspection.
(2) Thereafter, repeat the inspections in paragraphs (e)(1)(i) through (e)(1)(ii) of this AD as follows:
(i) At every installation of a RH rear half-wall P/N 0 319 99 824 0 on an installed engine, and
(ii) After every installation or reinstallation of an engine with a RH rear half-wall P/N 0 319 99 824 0 installed.
(3) If the P3 air pipe (first section) or the RH rear half-wall P/N 0 319 99 824 0 is found damaged, then before further flight, replace the damaged part(s) with parts eligible for installation.
(4) If the P3 air pipe (first section) and the RH rear half-wall P/N 0 319 99 824 0 are found contacting each other but are not damaged, replace the RH rear half-wall with a RH rear half-wall eligible for installation.
(5) If both the P3 air pipe (first section) and the RH rear half-wall are found not damaged during the inspections specified in paragraph (e)(1) or (e)(2) of this AD, and the clearance between them is less than 0.5 mm, but they are not contacting each other, then repeat the inspection in paragraphs (e)(1)(i) and (e)(1)(ii) of this AD within every 100 EH.
(6) Installation of RH rear half-wall, P/N 0 319 99 008 0, is terminating action to the inspections required by paragraphs (e)(1), (e)(2), and (e)(5) of this AD.
(7) Once a RH rear half-wall, P/N 0 319 99 008 0, is installed on an engine, do not install a RH rear half-wall, P/N 0 319 99 824 0, on that engine.
For the purpose of this AD, parts eligible for installation is defined as:
(1) An undamaged P3 air pipe (first section).
(2) An undamaged RH rear half-wall P/N 0 319 99 824 0.
(3) A new design RH rear half-wall P/N 0 319 99 008 0.
An inspection performed on an installed engine before the effective date of this AD using Turbomeca MSB No. 319 75 4810, Version A, dated May 14, 2008, satisfies the inspection requirement in paragraphs (e)(1)(i) and (e)(1)(ii) 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.
Engines
