AD 61-24-01

61-24-01 BOEING AND DOUGLAS: Amdt. 369 Part 507 Federal Register November 23, 1961. Applies to all 707/720 Series and DC-8 Series aircraft equipped with Pratt & Whitney Aircraft JT3C-12, JT3D-1, JT3D-1-MC6, JT3D-1-MC7, and JT3D-3 engines.

Compliance required as indicated.

A recent failure of the low compressor turbine shaft resulted in overspeeding and separation of the low compressor turbines. To prevent recurrence of this difficulty, the following action is required on any turbine engine that has been disassembled since last overhaul to the extent of exposing any bearing compartment:

At periods not to exceed 12 hours' time in service, the main oil screen shall be disassembled, inspected and cleaned in accordance with Pratt and Whitney Overhaul Manual. The inspection shall be repeated until the screen is free of contamination for two successive inspections. If contaminants indicative of engine part failure or contaminants in sufficient quantity to plug the oil screen are found during any inspection the engine shall not be operated until the cause of the difficulty has been determined and satisfactorily corrected.

Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Eastern 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 increase for such operator.

(Pratt and Whitney telegram to all turbojet engine operators dated November 9, 1961, covers the same subject.)

This directive effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated November 10, 1961.

Revised February 13, 1962, and June 7, 1962.