80-19-03 PRATT & WHITNEY AIRCRAFT: Amendment 39-3911. Applies to all Pratt & Whitney Aircraft JT3D-1-MC7 turbofan engine models.
Compliance required not later than December 31, 1980.
To preclude high cycle fatigue cracking of fifth stage compressor disks which could result in disk fracture, retire from service all fifth stage compressor disks, P/N 426505, and replace with either disk P/N 697105 or P/N 749605.
Upon submission of substantiating data, through an FAA Aviation Safety Inspector, the Chief, Engineering and Manufacturing Branch, New England Region, may adjust the compliance date.
A historical file on this AD is maintained in full by the FAA at its headquarters in Washington, D.C., and at the New England Region.
This amendment becomes effective October 7, 1980.