AD 2002-26-05: Air Tractor, Inc. Models AT-502, AT-502A, AT-502B, and AT-503A Airplanes

This AD applies to certain Models AT-502, AT-502A, AT-502B, and AT-503A airplanes. Use paragraph (a)(1) of this AD for airplanes that do not incorporate and never have incorporated winglets. Use paragraph (a)(3) of this AD for certain AT-500 series airplanes that incorporate or have incorporated Marburger Enterprises, Inc. winglets. (1) The following presents airplanes (certificated in any category) that are affected by this AD, along with the new safe life (presented in hours time-in-service (TIS)) of the wing lower spar cap for all affected airplane models and serial numbers: Model Serial Nos. Safe life AT-502 0003 through 0236 1,650 hours TIS AT-502A All serial numbers beginning with 0158.. 1,650 hours TIS AT-502B All serial numbers beginning with 0187.. 1,650 hours TIS AT-503A All serial numbers beginning with 0067.. 1,650 hours TIS (2) If piston powered aircraft have been converted to turbine power, you must use the limits for the corresponding serial number turbine-powered aircraft. (3) The following presents airplanes (certificated in any category) that could incorporate or could have incorporated Marburger Enterprises, Inc. winglets. These winglets are installed in…