71-11-02 AVCO LYCOMING: Amdt. 39-1208 as amended by Amendment 39-1403. Applies to all IO- 360A and -C Series engines with serial numbers 1734-51A through 4412-51A and all such series engines remanufactured between 1 September 1965 and 11 October 1967.
Compliance required as indicated, unless already accomplished.
To prevent valve failures replace the intake and exhaust hydraulic tappet plunger assembly P/N 76290 with P/N 78290 at the time in service specified below:
(a) Engines with less than 400 hours in service on P/N 76290 as of the effective date of this AD, shall comply prior to the accumulation of 450 hours in service.
(b) Engines with 400 or more hours in service on P/N 76290 as of the effective date of this AD shall comply within the next 50 hours in service.
(Note: Lycoming Service Bulletin No. 328 covers this subject.)
Amendment 39-1208 was effective May 19, 1971.
This Amendment 39-1403 is effective March 14, 1972.