Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Bombardier Inc. Model (Otter) DHC-3 airplanes that have been modified by 524085 BC, Ltd. Supplemental Type Certificate (STC) Number ST01243NY. This proposed AD would require you to replace the existing Viking Air Ltd. elevator servo tab assembly with a redesigned Viking Air Ltd. elevator servo tab assembly. This proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Canada. There has been one failure of the elevator servo tab assembly. We are issuing this proposed AD to prevent the structural failure of the elevator servo tab. This failure could lead to loss of control of the airplane.