87-16-02: Propeller Blade Pilot Tube Bore

87-16-02 HARTZELL: Priority letter issued July 31, 1987. Applies to Model HC-B5MP- 3C/M10876K propellers installed on Short Brothers Model SD3-60 aircraft. This priority letter AD is effective immediately upon receipt. Compliance is required, as indicated, unless already accomplished. To prevent propeller blade separation near the hub which could result in engine separation from the aircraft, accomplish the following: (a) Until compliance with paragraph (b), remove propeller from aircraft, disassemble propeller, penetrant inspect and rework, as required, the blade pilot tube bore, in accordance with Hartzell Service Bulletin No. 136D, dated May 23, 1986, in accordance with the following schedule: TIME SINCE NEW (TSN) - HOURS INSPECT/REWORK Less than or equal to 3000 Prior to exceeding 3000 hours time in service or 250 additional flights from the effective date of this priority letter AD, whichever occurs later, and thereafter at intervals not to exceed 300 flights. Greater than 3000 and have accumulated excess of 300 flights since last inspection per Service Bulletin 136D Reinspect/rework prior to accumulation of an additional in 250 flights from the effective date of this priority letter AD, and thereafter at intervals not to exceed 300 flights. Greater than 3000 and have accumulated less than or equal to 300 flights since last inspection per Service Bulletin 136D. Reinspect/rework prior to accumulation of 300 flights since last inspection or 250 additional flights from the effective date of this priority letter AD, whichever occurs later, and thereafter at intervals not to exceed 300 flights. (b) Remove from service (retire) and replace blade Model M10876K with new design blade Model M10876ASK, or Federal Aviation Administration (FAA) approved equivalent, prior to March 31, 1988. Aircraft may be ferried in accordance with the provisions of Federal Aviation Regulations (FAR's) 21.197 and 21.199 to a base where the AD can be accomplished. Upon request, an equivalent means of compliance with the requirements of this priority letter AD may be approved by the Manager, Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des Plaines, Illinois 60018. Upon submission of substantiating data by an owner or operator through an FAA Maintenance Inspector, the Manager, Chicago Aircraft Certification Office, may adjust the compliance time specified in this priority letter AD. Documents pertinent to this priority letter AD may be obtained from Hartzell Propeller Products Division, TRW Aircraft Components Group, 350 Washington Avenue, Piqua, Ohio 45356, or may be examined at the Office of the Regional Counsel, FAA, Rules Docket No. 87- ANE-27, 12 New England Executive Park, Burlington, Massachusetts 01803. Federal Register publication to follow. This priority letter AD issued July 31, 1987, is effective immediately upon receipt.