AD 72-25-02

72-25-02 ROLLS ROYCE (1971) LIMITED: Amendment 39-1567 as amended by Amendment 39-1624. Applies to Rolls Royce Continental engines that have oil pump drive gear P/N's 22354/RR or 23403/RR installed. Those engines may include Model RR C90, except S/N's 11R021 and subsequent; Model RR O-200 engines, except S/N's 23R590 through 23R600 and 23R638 and subsequent and Model RR O-300 engines, except S/N's 31R162 and subsequent. Compliance required as indicated. To prevent the loss of oil pressure due to excessive wear of oil pump drive gear P/N's 22354/RR or 23403/RR accomplish the following: (a) Within the next 25 hours' time in service after the effective date of this AD, unless already accomplished within the last 25 hours' time in service before the effective date of this AD, and thereafter at the intervals specified in paragraph (b), determine the amount of back lash (angular movement) in the oil pump drive gear in accordance with Rolls Royce Service Bulletin No. T-200, dated November 26, 1971, or an FAA-approved equivalent. (b) If the amount of back lash (angular movement) determined in accordance with paragraph (a) during an inspection required by paragraph (a) or this paragraph is - (1) Six degrees or less, continue to inspect in accordance with paragraph (a) at intervals not to exceed 300 hours' time in service since the last inspection; (2) More than 6 degrees but not more than 10 degrees, continue to inspect in accordance with paragraph (a) at intervals not to exceed 100 hours' time in service since the last inspection; (3) More than 10 degrees but not more than 14 degrees, continue to inspect in accordance with paragraph (a) at intervals not to exceed 25 hours' time in service since the last inspection; (4) More than 14 degrees, before further flight, replace oil pump drive gear P/N's 22354/RR or 23403/RR, as applicable, with - (i) An improved oil pump drive gear as specified in Rolls Royce Service Bulletin No. T-200, dated November 26, 1971, or an FAA-approved equivalent; or (ii) An oil pump drive gear of the same part number with 14 degrees or less of back lash (angular movement), determined in accordance with paragraph (a), and continue to comply with paragraph (b), as applicable. (c) The repetitive inspections required by subparagraphs (b)(1), (b)(2), (b)(3), and (b)(4)(ii) may be discontinued when oil pump drive gear P/N's 22354/RR or 23403/RR are replaced with improved oil pump drive gear as specified in Rolls Royce Service Bulletin No. T-200, dated November 26, 1971, or an FAA-approved equivalent. NOTE: Copies of Rolls Royce Service Bulletin No. T-200, dated November 26, 1971, may be obtained by request to the following address:

Teledyne Continental Motors Attention: Circulation Department P.O. Box 90 Mobile, Alabama 36601

Amendment 39-1567 became effective December 4, 1972. This amendment 39-1624 becomes effective April 23, 1973.