Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all EMBRAER Model EMB-120 series airplanes. This proposal would require revising the Airplane Flight Manual to ensure that the propeller synchronizer switch is "OFF" after engine start and before takeoff and landing. This action is necessary to prevent a possible loss of airplane control and subsequent injury to the flight crew and passengers. This action is intended to address the identified unsafe condition.