Maintenance Our shop at Midstate Aviation can maintain Part 91 and Part 135 aircraft to include annuals, 100-hours, and routine maintenance. We have a limited repair station for IFR bi-annual checks as required by CFR 91. Our maintenance staff includes three full time Airframe & Powerplant Mechanics (A&P), two full time Inspection Authorities (IA), and Piper fleet operator status. Ed Beeson, Director of Maintenance, has over 25 years of hands on experience and was awarded WA State Division of Aviation: Mechanic of the Year in 2000.