AD FAA-2007-28432

We are adopting a new airworthiness directive (AD) for certain Thrush Aircraft, Inc. (Thrush) Model S2R series airplanes. This AD requires you to do repetitive visual inspections of the vertical and horizontal stabilizer attach fitting, attach fitting bolts, and the vertical fin aft spar for cracks or corrosion. This AD also requires immediate replacement of the vertical and horizontal stabilizer attach fittings and attach fitting bolts if cracked or corroded parts are found, and the inspection of the vertical fin aft spar with repair or replacement if cracks or corrosion are found. This AD requires the eventual replacement of the vertical and horizontal stabilizer attach fittings and attach fitting bolts if no corrosion or cracks are found as terminating action for the repetitive inspections. This AD results from reports of cracks in the empennage of Thrush S2R series airplanes. We are issuing this AD to detect and correct these cracks, which could cause the vertical stabilizer to lose structural integrity. This failure could lead to loss of control.