Summary
This document proposes to adopt a new airworthiness directive (AD) that would apply to certain deHavilland Inc. (deHavilland) Model Otter DHC-3 airplanes modified by supplemental type certificate (STC) No. SA3777NM. The proposed action would require modifying the airplane's electrical system. The actions specified by the proposed AD are intended to prevent electrical system failure, which, if not corrected, could result in the loss of the engine instruments or a possible electrical fire in the airplane's cockpit.