63-22-04 PIAGGIO: Amdt. 635 Part 507 Federal Register October 30, 1963. Applies to All Model P.166 Aircraft.
Compliance required within 50 hours' time in service after the effective date of this AD.
As a result of failures of the main landing gear shock absorber the following modifications must be accomplished in the manner specified in Piaggio Service Bulletin 166- 25A.
(a) Install Teflon sealing gasket P/N 4/22015.52 on inner ring nut of shock absorber casing.
(b) Replace light alloy piston bottom with steel P/N 4/22015.55.
(c) Replace the present ring nut with P/N 4/22015.56.
(d) Shock absorbers modified as specified herein shall have a letter "D" placed on the nameplate.
(e) Shock absorbers modified as specified herein shall be overhauled every 1,200 hours' time in service or every 2 years, whichever occurs first.
This directive effective December 2, 1963