Summary
We propose to supersede an existing airworthiness directive (AD) that applies to certain TCM and R-RM series reciprocating engines. The existing AD currently requires replacement of certain magnetos if they fall within the specified serial number (S/N) range, inspection of the removed magneto 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. Since we issued that AD, we became aware of an error in the previous AD applicability in the range of magneto S/ Ns affected, and of the need to include certain engines made by R-RM, under license of TCM. This proposed AD would correct the range of S/Ns affected, require the same replacement and inspections, and would add R-RM C-125, C-145, O-300, IO-360, TSIO-360, and LTSIO-520-AE series reciprocating engines to the applicability. We are proposing this AD to correct the unsafe condition on these products.