63-18-05 ROLLS-ROYCE: Amdt. 606 Part 507 Federal Register August 22, 1963. Applies to All Tyne 512 and 515 Engines.
Compliance required as indicated.
To prevent failure of the high pressure cooling air manifold accomplish the following:
(a) If not already accomplished within the past 475 hours' time in service, within the next 25 hours' time in service after the effective date of this AD, and thereafter at intervals not exceeding 500 hours' time in service from the last inspection, inspect the joints adjacent to the flanged connections of the high pressure cooling air manifold for cracks. Cracks across the tack welds are acceptable, however if cracks are found in the parent metal of the flange or pipe connection replace the complete high pressure cooling air manifold assembly before further operation.
(b) Upon incorporation of an FAA approved modification or compliance with Section 4(b) of Rolls-Royce Alert Service Bulletin No. Ty A.72-438 revised June 24, 1963, the special inspections in (a) can be discontinued.
(c) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, International Engineering and Manufacturing Branch, FAA International Division, 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 such operator.
(Rolls-Royce Alert Service Bulletin No. Ty A.72-438 revised June 24, 1963, covers this same subject.)
This directive effective September 21, 1963.