AD 51-10-04

51-10-04 CESSNA: Applies to Model 190 Aircraft, Serial Numbers 7004 Through 7594.

Inspection required not later than May 1, 1951, and every 25 hours of operation thereafter until new cowl mounting ring channels and channel stiffening angles are installed.

Due to cracking and failures of the cowl mounting ring channels which, if undetected, may result in the cowl moving forward into the propeller, the cowl mounting channels must be closely inspected for cracks with particular attention being paid to the sections which bear against the cowl mounting lugs. This inspection must be repeated every 25 hours of operation until the presently installed 1010 steel cowl mounting channels are replaced with 4130 steel cowl mounting channels, Cessna P/N 0352161, 0352163, and 0352163-1, and aluminum alloy cowl channel reinforcing angles, Cessna P/N 0352146, 0352147-1, 0352147-2, 0352152-5, and 0352152-6 are installed. In the event that inspection reveals any indication of cracks, the new cowl mounting channels and reinforcing angles must be installed immediately.

(Cessna Service Letter No. 13 dated March 29, 1951, covers this same subject.)