Airworthiness Directives; Air Tractor, Inc. Models AT-802 and AT-802A Airplanes

We are adopting a new airworthiness directive (AD) to supersede AD 2006-08-09, which applies to all Air Tractor, Inc. (Air Tractor) Models AT-802 and AT-802A airplanes. AD 2006-08-09 currently requires you to repetitively inspect (using the eddy current method) the two outboard fastener holes in both of the wing main spar lower caps at the center splice joint for cracks and repair or replace any cracked spar cap. Since we issued AD 2006-08-09, we have determined we need to clarify the serial numbers (SNs) of the Models AT-802 and AT- 802A airplanes affected by that AD. Additionally, we are adding an option of modifying the wing main spar lower caps to extend the safe life limit on the affected airplanes. Consequently, this AD would keep the actions of AD 2006-08-09, clarify the affected SNs, and add a modification option to extend the safe life limit. We are issuing this AD to detect and correct cracks in the wing main spar lower cap at the center splice joint, which could result in failure of the spar cap and lead to wing separation and loss of control of the airplane.