Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-135BJ, -135ER, -135KE, -135KL, -135LR, -145, -145ER, -145MR, -145LR, -145XR, -145MP, and -145EP Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain EMBRAER airplane models as identified above. This AD requires modifying the total air temperature (TAT) sensor heating system. This AD also allows replacing the fully automated digital electronic control (FADEC) assemblies with new or modified assemblies as an additional means of compliance. This AD results from a report indicating that the FADEC unit failed to compensate for ice accretion on the engine fan blades due to a false temperature signal from the TAT sensor to the FADEC. We are issuing this AD to prevent failure of the TAT sensor, which could result in insufficient thrust to take off or (if coupled with the loss of an engine during takeoff) to abort the takeoff in a safe manner, and consequent reduced controllability of the airplane.