Airworthiness Directives; Air Tractor, Inc. Model AT-501 Airplanes

The FAA is adopting a new airworthiness directive (AD) to revise AD 2002-11-05, which applies to certain Air Tractor, Inc. (Air Tractor) AT-400 series and Models AT-501, AT-802, and AT-802A airplanes. AD 2002-11-05 establishes a safe life for the wing lower spar cap. Since we issued AD 2002-11-05, we have received reports of cracks found prior to the established safe life on AT-400 series airplanes and on Model AT-802A airplanes. We are issuing separate AD actions for AT-400 series and Models AT-802 and AT-802A airplanes to address the unsafe condition of those airplanes. This AD retains the actions required in AD 2002-11-05 for Model AT-501 airplanes and removes AT-400 series and Models AT-802 and AT-802A airplanes from the applicability of AD 2002-11-05.