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AD/LYC/89 Amdt 4 - Crankshaft Gear
Lycoming Piston EnginesLycoming Piston Engines
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Lycoming Piston Engines
| AD/LYC/89Amdt 4 | Crankshaft Gear | 20/2014 |
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| Applicability: | This Airworthiness Directive (AD) applies to all Textron Lycoming direct drive piston engines; excepting the O-145, O-320H,O-360E, LO-360E, LTO-360E, TO-360E, O-435 and TIO-541 series engines. |
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| Requirements: | 1. Inspect, and if necessary repair, the crankshaft counter bored recess, the alignment dowel, the bolt hole threads, and the crankshaft gear for wear, galling, corrosion, and fretting in accordance with Lycoming Mandatory Service Bulletin No. 475C dated 30 January 2003 (MSB No. 475C) or later revision approved by the United States of America Federal Aviation Administration (FAA).2. Remove the existing gear retaining bolt and lockplate from service, and install a new bolt and lockplate, in accordance with Lycoming MSB No. 475Cor later revision approved by FAA.3. Do not install into any engine the gear retaining bolt and lockplate removed in compliance with this AD.Note: FAA AD 2004-10-14 Amendment 39-13644 refers. |
| Compliance: | 1. The actions in Requirements 1, 2 and 3 must be taken at each removal of the engine following a propeller strike event. |
| For the purpose of this AD, a propeller strike event is defined as follows:(a) Any incident, whether or not the engine is operating, that requires repair to the propeller other than minor dressing of the blades.(b) Any incident during engine operation in which the propeller impacts a solid object that causes a drop in revolutions per minute (RPM) and also requires structural repair of the propeller (incidents requiring only paint touch-up are not included). This is not restricted to propeller strikes against the ground.(c) A sudden RPM drop while impacting water, tall grass, or similar yielding medium, where propeller damage is not normally incurred. |
| (d) The preceding definitions include situations where an aircraft is stationary and the landing gear collapses causing one or more blades to be substantially bent, or where a hanger door (or other object) strikes the propeller blade. These cases should be handled as sudden stoppages because of potentially severe side loading on the crankshaft flange, front bearing, and seal. | |
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