66-08-04 MARTIN: Amdt. 39-207 Part 39 Federal Register March 11, 1966. Applies to Models 202, 202A, and 404 Airplanes.
Compliance required as indicated.
To detect and repair cracks in the piston of the piston and fork assembly of the nose landing gear, accomplish the following:
(a) For nose landing gear piston and fork assembly, P/N 202SD84483, with 6,000 or more hours' time in service on the effective date of this AD, comply with (c) within the next 100 hours' time in service unless already accomplished within the last 350 hours' time in service and thereafter at intervals not to exceed 450 hours' time in service from the last inspection.
(b) For nose landing gear piston and fork assembly, P/N 202SD84483, with less than 6,000 hours' time in service on the effective date of this AD, comply with (c) before the accumulation of 6,100 hours' time in service, unless accomplished in the 350 hours' time in service from 5,650 hours' to 6,000 hours', and thereafter atintervals not to exceed 450 hours' time in service from the last inspection.
(c) Inspect for cracks around the periphery of the lower part of the piston from the hard chrome piston finish, to where the piston blends into the barrel (just above the fork junction) including the radii which blends the piston section into the barrel section of the terminal using dye penetrant with at least a 10-power glass or an equivalent FAA-approved method.
(d) If a crack is found, the piston and fork assembly must be repaired by grinding out the crack to a depth not to exceed 0.030 inch, or replace with a part of the same part number, or an equivalent approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. The depth of material removable must be measured from the plane of the piston surface. The reworked area must be blended into the piston surface. The surface finish after grinding must be equivalent to RMS-32 with no tool marks present. One flight may be made inaccordance with the provisions of FAR 21.197 for the purpose of obtaining these modifications.
NOTE - The length of grindout may be extended completely around the periphery of the piston surface.
(e) Repaired piston and fork assemblies must be inspected in accordance with (c) within the next 50 hours' time in service after the repair, and thereafter at intervals not to exceed 150 hours' time in service from the last inspection.
(f) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Eastern Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator.
This directive effective April 10, 1966.