Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain de Havilland Model DHC-8- 100, -200, and -300 series airplanes. This proposal would require modification of the attitude and heading reference systems (AHRS). This proposal is prompted by a report of loss of power to both AHRS's during flight due to a faulty terminal block to which the signal ground for the AHRS's are connected. The actions specified by the proposed AD are intended to prevent simultaneous power loss to both AHRS's, which could result in reduced controllability of the airplane.