Airworthiness Directive · Amendment 39-18556 · Turbomeca S.A. Turboshaft Engines
Turbomeca S.A. Turboshaft Engines
This AD applies to Turbomeca S.A., Astazou XIV B and XIV H turboshaft engines with the following part number (P/N) and serial number (S/N) third stage turbine wheels that incorporate modification AB 173 (Turbomeca S.A. Service Bulletin (SB) No. 283 72 0091) or modification AB 208 (Turbomeca S.A. SB No. 283 72 0117). This AD does not apply to third stage turbine wheels that incorporate Turbomeca S.A. SB No. 283 72 805.
(1) Third stage turbine wheels, P/N 0 265 25 700 0, all S/Ns;
(2) Third stage turbine wheels, P/N 0 265 25 702 0, all S/Ns;
(3) Third stage turbine wheels, P/N 0 265 25 706 0, all S/Ns;
(4) Third stage turbine wheels, P/N 0 265 25 705 0, with an S/N listed in Appendix 2.1 of Turbomeca S.A. Mandatory Service Bulletin (MSB) No. 283 72 0804, Version D, dated July 24, 2015.
We are superseding airworthiness directive (AD) 2010-11-10 for all Turbomeca S.A. Astazou XIV B and XIV H turboshaft engines. AD 2010- 11-10 requires inspection of certain third stage turbine wheels and removal of any damaged wheel. This AD requires expanding the population and frequency of repetitive inspections. This AD was prompted by a report of a third stage turbine wheel crack detected during engine overhaul. We are issuing this AD to prevent uncontained failure of the third stage turbine wheel, which could result in damage to the engine and damage to the helicopter.
(1) Perform a dye penetrant inspection of the third stage turbine wheel. Use paragraph 2.4.2.2 of Turbomeca S.A. MSB No. 283 72 0804, Version D, dated July 24, 2015, to do the inspection, as follows:
(i) Inspect third stage turbine wheels with 300 engine cycles (EC) or more accumulated since last inspection, or since new, or since last overhaul, or since repair, within 100 EC after the effective date of this AD.
(ii) Inspect third stage turbine wheels with less than 300 EC accumulated since last inspection, or since new, or since last overhaul, or since repair, within 400 EC since last inspection, or since new, or since last overhaul, or since repair.
(2) Repeat the inspection required by this AD within 400 EC since last inspection.
(3) Remove from service any third stage turbine wheels that fail the inspection required by this AD.
Application of Turbomeca S.A. SB No. 283 72 0805, Version B, dated December 15, 2010 is terminating action for the inspections required by paragraphs (e)(1) and (2) 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
