70-16-02 DOWTY ROTOL: Amendment 39-1015 as amended by Amendment 39-1503. Applies to all Dowty Rotol propellers, installed on but not necessarily limited to the following airplanes: Fairchild Series F-27 and FH-227, Armstrong Whitworth AW 650, Grumman G-159, Viscount 700 and 810 series, Nihon YS-11, and Convair 240, 340, 440 turbopropeller conversions.
Compliance is required within the next 100 hours' time in service after the effective date of this AD, unless already accomplished.
(a) Inspect the blade pitch change operating link and eyebolt fork assembly for -
(1) Seizure (the link and eyebolt are seized if the torque required to move the link is 300 inch pounds or more); and
(2) Cadmium plating on the mating surfaces between the operating link and eyebolt fork and the holes through the eyebolt fork and the operating link.
(b) If the link and eyebolt fork are not seized and have not been cadmium plated, they may remain in service.
(c) If the linkand eyebolt fork are not seized but cadmium plating is found in the prohibited areas, remove the plating by means of wet or dry silicon carbide paper, fine or medium grade, and conduct a magnetic crack test. If no cracks are found, the assembly may remain in service until the next propeller overhaul for air carrier airplanes and airplanes under a continuous maintenance program or for 3,300 hours' time in service after the effective date of this AD for all other airplanes. At the next propeller overhaul for air carrier airplanes and airplanes under a continuous maintenance program, or within 3,300 hours' time in service after the effective date of this AD for all other airplanes, heat treat the links and eyebolt forks found to have been cadmium plated in order to remove embrittlement in accordance with Dowty Rotol Service Bulletin No. 61- 754, dated June 12, 1970, or later ARB-approved issue or an FAA-approved equivalent.
(d) If the link and eyebolt fork are seized, remove the linkand eyebolt fork from service and replace them with an assembly having a part number approved for that model propeller that has not been cadmium plated in the prohibited areas.
(e) If the link or eyebolt fork are found to be cracked during the inspection in paragraph (c), remove the cracked part from service and replace it with a part having a part number approved for that model propeller that has not been cadmium plated.
(f) The inspection required by paragraph (a) need not be performed and the propeller may remain in service if -
(1) The operator can show that no cadmium plating exists in the prohibited areas of that propeller; or
(2) It is a new propeller that has never been overhauled.
Amendment 39-1015 became effective July 25, 1970.
This Amendment 39-1503 becomes effective August 21, 1972.