What was found
AFTER 150 HOURS ON ACFT DURING SCHEDULED MAINTENANCE THE FIRST ONE OF THE TYPE OF PROBLEM WAS FOUND. MECHANICS ARE FINDING THE ALTERNATE AIR VALVE BODY CONTROL CABLE (PN NR DAI-9076-00-04) LOOSE OR COMPLETELY DISCONNECTED AND HANGING NEXT TO THE PRIMARY/ALTERNATE AIR VALVE BODY (PN D41-7166-20-30). THEN WHEN THEY TRY TO REINSTALL THE CABLE THEY ARE FINDING THAT THE THREADS ARE STRIPPED OUT ON THE ALTERNATE AIR VALVE BODY. THIS PROBLEM HAS NOW OCCURRED ON 14 DIFFERENT ACFT IN OUR FLEET ALL BETWEEN 150 TO 350 HOURS TTSN. MY CONCERN IS THAT THE OPERATOR OF THE ACFT (IF THE CABLE HAS BECOME DISCONNECTED) MAY NOT KNOW IF THE ENGINE IS GETTING FILTERED OR UNFILTERED AIR. THE FIX MIGHT BE THAT THE MANUFACTURE MAKES THE VALVE BODY THICKER (MORE THREADS), PUT IN A STEEL HELICOIL, OR MAYBE SPOT WELD A NUT ON THE OUTSIDE OF THE VALVE BODY.