Does anyone out there have a bad IO346A crankcase that still has the engine mount brackets and starter adapter on it that you might want to sell?
Bob Steward A&P-IA:
There is an AD (Ed. note: 95-03-14, see below) on the rear engine mount brackets, and they must be replaced if removed. Used ones that were the originals would be useless and illegal to re-install.
On April 19, 1994, the Federal Aviation Administration (FAA) issued airworthiness directive (AD) 94-09-07, Amendment 39-8896 (59 FR 23148, May 5, 1994), applicable to certain Teledyne Continental Motors (TCM) IO-346, IO-520, and IO-550 series reciprocating engines, to require initial and repetitive dye penetrant inspections for cracks in certain lower left engine mount brackets, Part Number (P/N) 630695. If the lower left engine mount bracket is found cracked, that AD requires replacing both the lower left and lower right engine mount brackets with improved design engine mount brackets, P/N 653306 and 653305, respectively. If a crack is not detected, the lower left engine mount bracket requires repetitive inspections at intervals not to exceed 500 hours time in service (TIS) until the next engine removal, at which time engine mount brackets, P/N 630694 and 630695, are replaced with improved design engine mount brackets, P/N 653306 and 653305. Installation of these improved design engine mount brackets constitutes terminating action to the inspection requirements of that AD. That action was prompted by reports of cracks in engine mount brackets on engines that have completed at least one overhaul cycle. That condition, if not corrected, could result in engine separation from the aircraft due to cracks in the engine mount brackets.
Since the issuance of that AD, the FAA has received reports of difficulty in identifying the engine mount brackets that must be inspected. The P/N is ink-stamped on the part and is quite easily obliterated. The problem arises when the Casting Number (C/N), which is different from the P/N, is mistaken for the P/N, and the AD is incorrectly believed to not apply.
The FAA has reviewed and approved the technical contents of TCM Mandatory Service Bulletin (MSB) No. MSB94-9, dated October 21, 1994, that provides positive identification of affected engine mount brackets that require inspection, and replacement, if necessary.
Since an unsafe condition has been identified that is likely to exist or develop on other engines of this same type design, this AD supersedes AD 94-09-07 to clarify the identification procedures to determine which engine mount brackets must be inspected. The actions are required to be accomplished in accordance with the MSB described previously.