Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Bombardier Model DHC-8- 100, -200, and -300 series airplanes. This proposal would require inspection to determine the orientation of the Wiggins fuel couplers of the fuel tank vent line and scavenge line in the right wing at station 249, and follow-on corrective actions. This action is necessary to prevent contact between the nuts of the Wiggins fuel couplers and the stiffener on the access panel of the upper surface of the right wing, which could compromise the lightning protection of the fuel tank of the right wing in the event of a lightning strike, and could result in possible fuel tank explosion. This action is intended to address the identified unsafe condition.