72-20-07 ROLLS ROYCE (1971) LTD: Amdt. 39-1529. Applies to Rolls Royce Spey Model 555-15 Series engines on which Spey Modification 5046 has not been incorporated. These engines are installed on, but not necessarily limited to, Fokker Model F-28 airplanes.
Compliance is required within the next 25 hours' time in service after the effective date of this AD, unless already accomplished within the last 975 hours' time in service prior to the effective date of this AD, and thereafter at intervals not to exceed 1,000 hours' time in service from the last inspection until Spey Modification 5046 is incorporated.
To prevent fretting of fuel tubes which could cause leakage of fuel under pressure into the engine compartment, accomplish the following:
(a) Inspect tubes, P/N's EU.20154A and EU.67548A, which run between the airflow control regulator and the R.P.M. signal transmitter and between the fuel flow regulator and the shut-off valve, respectively, for fretting and consequent loss of sectional thickness where the tubes meet immediately behind the P3 connection on the fuel flow regulator.
(b) If evidence of fretting is found during an inspection required by paragraph (a), before further flight, except that the airplane may be flown in accordance with FAR 21.197 to a base where the repair can be performed, remove the tubes P/N's EU.20154A and EU.67548A, and either:
(1) Rework and reinstall the affected tubes in accordance with Rolls Royce Spey Service Bulletin No. Sp 73-A161 dated February 2, 1972 or an FAA-approved equivalent; or
(2) Replace the affected tubes with serviceable tubes of the same part number in accordance with Rolls Royce Spey Service Bulletin No. Sp 73-A161 dated February 2, 1972 or an FAA-approved equivalent.
This amendment becomes effective October 2, 1972.