Existing gauges still work with the new A.D.!
The gauge is used for inspection of seat rail wear in Cessna aircraft. This gauge is designed to measure the actual radius wear near the seat stop holes. Notice the different sized step the corner. The size applies to the .42 diameter limits referred to by the A.D. The .020 upper surface wear allowance allowed by the A.D. is designed into the gauge.
Note: Earlier versions of the McFarlane seat rail wear gauge feature a .36 and a .42 step. The .36 step was included per an earlier version of the A.D. and is no longer used. Existing gauges may still be used to check wear limits per the new A.D. Future production runs will not include the .36 part of the gauge.
For ordering details, go to part number GAUGE SR1.