85-08-02 TELEDYNE CONTINENTAL MOTORS: Amendment 39-5029. Applies to TCM new and rebuilt engines, IO-470-C, S/Ns 242071 through 242076; O-470-K, S/Ns 49390 through 49394; O-470-L, S/Ns 69640 through 69643; O-470-M, S/Ns 54141 and 54142; O-470-R, S/Ns 238170, 238171, 238176 through 238197, 238199 through 238211, 238213, 238215 through 238218, 238223, 238224, 466653 and 466654; O-470- S S/N 226443, 226444, 226446 through 226457; and all cylinder assemblies P/N 646680A4 and 646680A5 in inventory or installed on engines IO-470-C, O-470-G, -K, -L, -M, -R, -S since March 1984.
After April 30, 1985, compliance is required as indicated unless already accomplished:
(a) Compliance required within the next 10 hours time in service for the affected engines with cylinder assemblies having P/Ns 646680A4 and 646680A5 installed.
(b) Compliance is required prior to installation on an engine for uninstalled cylinder assemblies with P/Ns 646680A4 and 646680A5.
To prevent possible valve stemwear, oil contamination, valve seizure, and total loss of engine power, accomplish the following:
(a) Inspect each specified engine and cylinder assembly for the P/N stamped on the base flange of the cylinder.
NOTE: This AD applies only to the specified engines and cylinder assemblies having P/Ns 646680A4 and 646680A5.
(1) If an inspection reveals no specified engines or cylinder assemblies in stock, no further action is required by this AD.
(2) If inspection of any of the specified engines reveals no cylinder assemblies with P/Ns 646680A4 or 6466680A5, make appropriate engine log book entry stating in effect that this engine has been inspected in accordance with this AD. Return engine to service. No further action is required by this AD.
(3) If inspection of any of the specified engines or aftermarket stock reveals cylinder assemblies having P/Ns 646680A4 or 646680A5, comply with paragraphs (b), (c), (d), (e), and (f).
(b) Remove the cylinder assemblies (P/N 646680A4 and/or P/N 646680A5) from stock or from the engine, as applicable, and replace the exhaust valve, P/N 626540, with P/N 637781 exhaust valve.
NOTE: The exhaust valves, gaskets, and seals necessary to accomplish this modification are listed by P/N in TCM SB M85-3, dated February 4, 1985, and can be purchased through TCM distributors.
(c) Inspect the valve guide for any metal transferred from the valve stem. If present, remove using a 1/4- inch diameter by approximately 8-inch long mandrel wrapped with 180 grit crocus paper. Polish the guide only enough to remove the transferred material. After polishing, the guide inside diameter must not exceed the service limit of 0.4405 inch.
(d) Restamp the cylinder assemblies with P/N 646680A7 after replacing the valves and polishing the valve guides, if required.
(e) Return the cylinder assemblies to stock or reinstall on the engine, as applicable.
NOTE: Reinstall cylinder assemblies using the procedures outlined in the Maintenance and Overhaul Manual for O-470 and IO-470 Series Aircraft Engines published by TCM under Form No. X30022A.
(f) Make appropriate maintenance record entry showing compliance with this AD.
Aircraft may be ferried in accordance with the provisions of Federal Aviation Regulations (FARs) 21.197 and 21.199 to a base where the AD can be accomplished.
Upon request, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Atlanta Aircraft Certification Office, 1075 Inner Loop Road, College Park, Georgia 30337.
The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain copies upon request to Teledyne Continental Motors, Aircraft Products Division, P.O. Box 90, Mobile, Alabama 36601. These documents also may be examined at the Office of the Regional Counsel, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, and in the Central File Room of the Atlanta Aircraft Certification Office, 1075 Inner Loop Road, College Park, Georgia 30337, weekdays, except Federal Holidays, between the hours of 8:00 a.m. and 4:30 p.m.
This amendment becomes effective on April 15, 1985.