wolit@rabbit.UUCP (08/15/83)
In June, as I was about to take off from Logan airport into drizzle and low overcast (and just a few tach minutes after bouncing around in a storm cell I hadn't wanted to penetrate), the suction pump on my 1976 Grumman Cheetah failed, leaving me with no vacuum-driven gyros. The other day, I was looking over the Instruction Manual that came with the new Airborne Dry Air Pump that the nice folks at Butler aviation installed for me, and discovered the following paragraph in the section on "Inspection and Maintenance Procedure (100 Hour / Annual Inspections)": Check the drive coupling and make sure it is in satisfactory condition. NOTE: SERVICE LIFE FOR COUPLINGS IS 6 YEARS. AFTER THAT, THEY SHOULD BE REPLACED WITH THE PROPER AIRBORNE COUPLING KIT. (Emphasis in original.) This replacement had not been done at my last annual -- which was the plane's sixth. Not that I can fault my mechanic -- nowhere in the Grumman Service Manual is this lifetime limitation mentioned. Is there any systematic procedure for keeping accessory manufacturers' Service Letters straight? Is it necessary for EACH A&P to check EACH manufacturer's manual for EACH part on EACH plane worked on? Are these sorts of things generally ignored unless they result in an AD issued against every model employing the affected part? Am I wrong to feel confident of having an airworthy plane after an annual inspection? Jan Wolitzky, BTL Murray Hill, 201 582-2998