More magnetos would be replaced under proposed AD

June 28, 2011

The FAA has proposed an airworthiness directive (AD) that would correct the applicability of an existing AD requiring replacement of some magnetos installed on some Teledyne Continental (TCM) and Rolls-Royce Motors (R-RM) engines.

The proposed AD would supersede a June 17, 2002, AD that requires replacement of specified magnetos, inspection of the removed magnetos to verify that the stop pin is still in place, and, if the stop pin is not in place, inspection of the engine gear train, crankcase, and accessory case. The 2002 AD was issued to “prevent engine failure and loss of control of the airplane due to migration of the magneto impulse coupling stop pin out of the magneto frame and into the gear train of the engine,” the FAA’s notice of the proposed AD said.

Since the original AD was issued, the FAA has become aware of an error in its applicability as concerns the range of magneto serial numbers affected, “and of the need to include certain engines made by R-RM, under license of TCM.”

The superseding AD would correct the range of magneto serial numbers to 99110001 through 99129999 inclusive. It would require the same replacement and inspections as the previous AD, and add R-RM C-125, C-145, O-300, IO-360, TSIO-360, and LTSIO-520-AE series reciprocating engines to the applicability of the original AD (which applied to TCM C-125, C-145, O-300, IO-360, TSIO-360, and LTSIO-520-AE series reciprocating engines).

The proposed AD was issued in a revised format from the original, and includes a table showing paragraph rearrangements and the corresponding paragraph identifiers for the original and superseding directives.

Members may submit comments on the proposed AD by Aug. 12 online, or by mail to Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington, D.C. 20590.