Airworthiness Directives; Air Tractor, Inc. Airplanes

The FAA is superseding Airworthiness Directive (AD) 2023-15- 07, which applied to all Air Tractor, Inc. (Air Tractor) Model AT-802 and AT-802A airplanes with Wipaire, Inc. Supplemental Type Certificate (STC) No. SA01795CH installed. AD 2023-15-07 required repetitively inspecting the left and right forward horizontal stabilizer spars for cracks, replacing any forward horizontal stabilizer spar found cracked, and reporting inspection results to the FAA. This AD requires repetitively inspecting the left and right, forward and rear, horizontal stabilizer spars for cracks at shorter intervals than those required by AD 2023-15-07, replacing any horizontal stabilizer spar found cracked or damaged, installing bathtub fittings, and reporting inspection results to the FAA. This AD was prompted by additional reports of cracks in the horizontal stabilizer spars and the need to incorporate a new finlet attach design on the horizontal stabilizer spars to reduce the cracking. The FAA is issuing this AD to address the unsafe condition on these products.