Summary
We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
Icing tunnel tests on an EMB-120 wing section, conducted under a joint Embraer-NASA-(National Aeronautics and Space Administration) FAA-CTA (Centro Tecnico Aeroespacial) research program well after the EMB-120( ) was type-certificated, have shown that stick shaker to stick pusher speed margins may drop below the minimum required by the applicable regulations in certain icing conditions. Although flight tests have shown that the aircraft handling qualities are not adversely affected, these reduced speed margins may significantly increase crew workload in certain flight phases.
The unsafe condition is reduced ability of the flightcrew to maintain the safe flight and landing of the airplane. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.