For checking seat rail wear limits as per FAA A.D. 87-20-03, Effective 09/24-/1990 Seat Rail Directive

The gauge is to be used for inspection of the Cessna seat rail wear. This gauge is designed to measure the actual radius wear near the seat stop holes. Notice the different sized steps in each corner. The sizes apply to the .36 and .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.

Download the Seat Track Gauge Instruction in PDF.