Airworthiness Directive · Amendment 39-14347 · Rolls-Royce Corporation (Formerly Allison Engine Company) 501-D22A, 501-D22C, and 501-D22G Turboprop Engines
Rolls-Royce Corporation (Formerly Allison Engine Company) 501-D22A, 501-D22C, and 501-D22G Turboprop Engines
This AD applies to Rolls-Royce Corporation (RRC) (formerly Allison Engine Company) 501-D22A, 501-D22C, and 501-D22G turboprop engines with the turbine wheels listed in the following Table 1, installed.
| Turbine wheel part number | Turbine wheel | Serial numbers |
|---|---|---|
| 6875431 | 1st Stage | KK50152 through KK50199. |
| 6845592 | 2nd Stage | KK40998 through KK41057. |
| 6845593 | 3rd Stage | KK36452 through KK36461, and KK36492 through KK36532. |
| 6870434 | 4th Stage | KK40320 through KK40393, and KK40485 through KK40535. |
These engines are installed on, but not limited to, Commercial Hercules L-382B, L-382E (L-100-20), L-382G (L-100-30), Airbus Super Guppy-201, Super Convair CV-580A, and CV5800 airplanes.
The FAA is adopting a new airworthiness directive (AD) for Rolls-Royce Corporation (RRC) (formerly Allison Engine Company) 501- D22A, 501-D22C, and 501-D22G turboprop engines. This AD requires a onetime inspection for proper metal hardness of certain 1st stage, 2nd stage, 3rd stage, and 4th stage turbine wheels. This AD results from a report of a turbine wheel found to be over dimensional limits, caused by improper metal hardness. We are issuing this AD to prevent uncontained turbine wheel failure, leading to damage of the airplane and total loss of engine power.
You are responsible for having the actions required by this AD performed at the next shop visit of the engine or turbine module, but not to exceed 7,400 cycles-since-new of any 1st stage, 2nd stage, 3rd stage, or 4th stage turbine wheel, unless the actions have already been done.
Perform a onetime inspection for proper metal hardness of 1st stage, 2nd stage, 3rd stage, and 4th stage turbine wheels. Use paragraphs 2.B. and 2.F. of RRC Commercial Engine Bulletins (CEBs) No. CEB-72-1138, No. CEB-72-4051, and No. CEB-72-1584, (combined in one document) dated January 23, 2004.
(g) Remove from service any turbine wheel that does not pass inspection, using paragraph 2.C. of RRC CEBs No. CEB-72-1138, No. CEB-72-4051, and No. CEB-72-1584, (combined in one document) dated January 23, 2004, and install a serviceable turbine wheel.
(h) Mark the letters, HC, after the serial number on any turbine wheel that passes inspection, using the method described in paragraph 2.D. of RRC CEBs No. CEB-72-1138, No. CEB-72-4051, and No. CEB-72-1584, (combined in one document) dated January 23, 2004.
(i) Report findings of inspections within 30 days of inspection using the procedures specified in paragraph 2.E of RRC CEBs No. CEB-72-1138, No. CEB-72-4051, and No. CEB-72-1584, (combined in one document) dated January 23, 2004. The Office of Management and Budget (OMB) has approved the reporting requirements specified in paragraph 2.E. of RRC CEBs No. CEB-72-1138, No. CEB-72-4051, and No. CEB-72-1584, (combined in one document) dated January 23, 2004, and assigned OMB control number 2120-0056.
For the purpose of this AD, a serviceable turbine wheel is:
(1) A turbine wheel that has a serial number not listed in this AD; and
(2) A turbine wheel that has a serial number listed in this AD that passed the inspection specified in paragraph (f) 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
