AD 62-22-02 ACTIVE

62-22-02 PRATT & WHITNEY: Amdt. 496 Part 507 Federal Register October 16, 1962. Applies to All Pratt & Whitney Aircraft JT3D-1 Turbofan Engines.

Compliance required as indicated.

To preclude failure of the fourth stage compressor rotor disc, P/N 393504, accomplish the following:

(a) For engines previously inspected by the procedure described in paragraph (c) or for engines which have been overhauled, inspect in accordance with paragraph (c) as follows:

(1) Inspect engines which have accumulated 235 or more hours' time in service since the last such inspection or engine overhaul within the next 130 hours' time in service after the effective date of this AD, and every 365 hours' time in service thereafter.

(2) Inspect engines which have accumulated less than 235 hours' time in service since the last such inspection or engine overhaul, prior to the accumulation of 365 hours' time in service since the last such inspection or engine overhaul and every 365 hours' time in service thereafter.

(b) For engines which have not previously been inspected by the procedure described by paragraph (c) and which have not been overhauled, inspect in accordance with paragraph (c) as follows:

(1) Inspect engines with 300 or more hours' time in service within the next 65 hours' time in service after the effective date of this AD, and every 365 hours' time in service thereafter.

(2) Inspect engines with less than 300 hours' time in service prior to the accumulation of 365 hours' time in service and every 365 hours' time in service thereafter.

(c) Remove the front accessory drive support assembly (NI gearcase) and the front accessory drive main spur gear (NI gearcase coupling). Using a strong light, visually inspect the fourth stage compressor rotor disc in the area between the disc bore and the spacer shoulder on the disc. If cracking is found, remove the engine for disc replacement prior to further flight.

(d) When fourth stagecompressor disc P/N 468304 is installed in place of P/N 393504, the repetitive inspections required by this AD are no longer required.

(e) The requirement for main oil screen inspections per AD 61-24-01 does not apply when the No. 1 bearing compartment is exposed for this disc inspection.

(f) 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 & Whitney Aircraft telegraphic message of August 21, 1962, to all JT3D operators, covers the same subject.)

This directive effective October 16, 1962.