Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-135 and -145 Series Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain EMBRAER Model EMB-135 and -145 series airplanes. This AD requires measuring the fillet radius dimension of the trunnion fitting webs of the wings; and reworking the fillet radius of the trunnion fitting web in order to increase the radius, doing related investigative actions, and doing applicable corrective action, if necessary. This AD is prompted by a report indicating that trunnion fittings of the wings have been manufactured with a web fillet radius smaller than the minimum required by the design data, which may induce the occurrence of fatigue cracks at the root of the trunnion fillet radius and adjacent structures (e.g., spar and ribs). We are issuing this AD to detect and correct fatigue cracking of the wing trunnion fittings or adjacent structure, which could result in failure of the main landing gear, consequent damage to surrounding structure, and possible loss of control of the airplane during landing.