Airworthiness Directives; Cessna Aircraft Company 180, 182, and 185 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that applies to all Cessna Aircraft Company (Cessna) 180, 182, and 185 series airplanes that have wing extension supplemental type certificate (STC) SA00276NY or supplemental type approval (STA) SA93-136 incorporated. This AD requires inspecting between wing station (W.S.) 90 and W.S. 110 for an angle stiffener at the lower wing spar splice. If the angle stiffener is not installed, this AD requires installing a reinforcing strap. This AD is the result of failed test results revealing that the wings of these Cessna airplanes, without the stiffener, do not meet the applicable design requirements after being modified by the above STC. The actions specified by this AD are intended to prevent wing failure during flight caused by the absence of an angle stiffener, which could cause loss of control of the airplane.