65-06-02 AERO PRODUCTS: Amdt. 39-47 Part 39 Federal Register March 13, 1965. Applies to A6441FN-606 Propeller Blades Shipped from Allison before February 19, 1965, That Have Not Been Overhauled.
Compliance required as indicated, unless already accomplished.
To prevent further blade failures as a result of fatigue cracks in the cuff ring, accomplish the following:
(a) Inspect blades with less than 750 hours' time in service on the effective date of this AD in accordance with (e) within the next 450 hours' time in service.
(b) Inspect blades with 750 or more but less than 1,000 hours' time in service on the effective date of this AD in accordance with (e) prior to the accumulation of 1,200 hours' time in service.
(c) Inspect blades with 1,000 or more but less than 1,600 hours' time in service on the effective date of this AD in accordance with (e) within the next 200 hours' time in service.
(d) Inspect blades with 1,600 or more hours' time in service on the effective date of this AD in accordance with (e) within the next 450 hours' time in service.
(e) Remove the spinner assembly, fairing assemblies, blade deicing slip ring assembly and attaching parts from the blade, and clean the blade surface in the cuff ring area in accordance with Allison Commercial Service Letter No. 168 dated March 1, 1965. Inspect the cuff ring area for cracks by fluorescent or nonfluorescent magnetic particle process in accordance with Allison Commercial Service Letter No. 168, or by an equivalent method approved by the Engineering and Manufacturing Branch, FAA Central Region.
(f) Remove cracked blades from service and report immediately by telephone or telegram to the Chief, Engineering and Manufacturing Branch, FAA Central Region, Kansas City, Missouri.
NOTE: During the inspection required by this AD, particular attention should be given to the cuff ring fillets.
This directive effective March 13, 1965.