75-15-04 DOWTY ROTOL: Amendment 39-2265. Applies to Dowty Rotol Type (c) R212/4-30-4/22 propellers incorporating hub and driving center assemblies. P/N's 601022294, 601022211, 601022105, and RA 64883, that have not been modified in accordance with Dowty Rotol Modification Nos. (c) VP2388-(SB61-604) or (c) VP2779(SB 61-767). These propellers are installed on, but not necessarily limited to, Hawker Siddeley Model H.S. 748 Series 2A airplanes.
Compliance is required as indicated.
To detect cracking of the propeller hub front wall/snout radius areas between the eyebolt guides, accomplish the following:
(a) Inspect the propeller hubs in accordance with Paragraph 2.A. of Dowty Rotol Service Bulletin No. 61-828, dated September 10, 1973, or an FAA-approved equivalent as follows:
(1) For those operators required to perform propeller overhauls, inspect at the next propeller overhaul and at each propeller overhaul thereafter.
(2) For all other operators, inspect within the next 4000 hours' time in service after the effective date of this AD, and thereafter inspect at intervals not to exceed 4000 hours' time in service since last inspection.
(b) Inspect those propeller hubs that have accumulated more than 10,000 hours' time in service on the effective date of this AD in accordance with Paragraph 2.B. of Dowty Rotol Service Bulletin No. 61-828, dated September 10, 1973, or an FAA-approved equivalent, unless already accomplished, as follows:
(1) For those propeller hubs that have never been inspected or that have accumulated more than 1400 hours' time in service since last inspected in accordance with Paragraph 2.A. or 2.B. of Dowty Rotol Service Bulletin No. 61-828, dated September 10, 1973, inspect within the next 600 hours time in service.
(2) For those propeller hubs that have accumulated not more than 1400 hours' time in service since last inspected in accordance with Paragraph 2.A. or 2.B. of Dowty Rotol Service Bulletin No.61-828, dated September 10, 1973, inspect prior to the accumulation of 2000 hours' time in service since last inspected.
(c) If a cracked hub is found during an inspection required by this AD, accomplish the following:
(1) Before further flight, replace the cracked hub with a serviceable part of the same part number or a part number approved for installation on the propeller.
(2) Inspect all the operator's propeller hubs covered by this AD in accordance with Paragraph 2.B. of Dowty Rotol Service Bulletin No. 61-848, dated September 10, 1973 or an FAA-approved equivalent as follows:
(i) For those propeller hubs that have accumulated more than 1400 hours' time in service since last inspected in accordance with paragraph (a) or (b) of this AD or that have never been inspected and have accumulated over 1400 hours' time in service, inspect within the next 600 hours' time in service; and, thereafter, continue to inspect at intervals not to exceed 2,000 hours' time inservice since last inspection
(ii) For those propeller hubs that have accumulated not more than 1400 hours' time in service since new or since last inspected in accordance with paragraph (a) or (b) of this AD, inspect prior to the accumulation of 2000 hours' time in service since last inspected or since new, as applicable, and, thereafter, continue to inspect at intervals not to exceed 2000 hours' time in service since last inspection.
(d) The inspections required by paragraphs (a), (b), and (c) of this AD may be discontinued upon the incorporation of Dowty Rotol Modification Nos. (c) VP 2388(SB61-604) or (c) VP 2779(SB61-767) or FAA-approved equivalent modifications.
(e) Upon request of an operator, an FAA maintenance inspector subject to prior approval of the Chief, Aircraft Certification Staff, Europe, Africa, and Middle East 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 adjustment.
This amendment becomes effective August 15, 1975.