Airworthiness Directive · Amendment 39-11290 · Teledyne Continental Motors O-470, IO- 470, TSIO-470, IO-520, TSIO-520, LTSIO-520, GTSIO-520, IO-550, TSIO- 550, and TSIOL-550 Series Reciprocating Engines
Teledyne Continental Motors O-470, IO- 470, TSIO-470, IO-520, TSIO-520, LTSIO-520, GTSIO-520, IO-550, TSIO- 550, and TSIOL-550 Series Reciprocating Engines
Teledyne Continental Motors (TCM) O-470, IO-470, TSIO-470, IO-520, TSIO-520, LTSIO-520, IO-550, TSIO-550, TSIOL-550, series new and rebuilt engines manufactured between January 1, 1998, and December 31, 1998, listed by serial number (S/N) in TCM Mandatory Service Bulletin (MSB) 99-3C, dated July 27, 1999. Also, GTSIO-520 series engines, listed by S/N in TCM Critical Service Bulletin (CSB) 99-6A dated July 21, 1999. This airworthiness directive (AD) is also applicable to any other TCM O-470, IO-470, TSIO-470, IO-520, TSIO-520, LTSIO-520, IO-550, TSIO-550, TSIOL-550, and GTSIO-520 series engines that were overhauled by facilities other than TCM, and that have had replacement crankshafts installed that were sold individually by TCM and were manufactured or rebuilt between January 1, 1998, and December 31, 1998.
This amendment adopts a new airworthiness directive (AD) that is applicable to Teledyne Continental Motors (TCM) O-470, IO-470, TSIO- 470, IO-520, TSIO-520, LTSIO-520, GTSIO-520, IO-550, TSIO-550, and TSIOL-550 series reciprocating engines. This action supersedes priority letter AD 99-09-17 that currently requires a one-time visual and ultrasonic (UT) inspection of the No. 2 and No. 5 crankshaft cheeks for cracks. All crankshafts found with a cracked cheek must be replaced with a serviceable crankshaft prior to further flight. This action adds to the applicability TCM GTSIO-520 series engines and additional engines, identified by serial numbers (S/Ns), of currently affected engine series; references a revised service bulletin that clarifies snap ring installation; increases to 500 hours time-in-service (TIS) the cutoff for engines that require a more immediate inspection; and corrects the contact telephone number for TCM. This amendment is prompted by inspection results from the current priority letter AD. The actions specified by this AD are intended to prevent crankshaft failure due to crankshaft cheek cracks, which could result in total engine power loss, in-flight engine failure, and possible forced landing.
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.
