Airworthiness Directives; Dornier Model 328-300 Series Airplanes Equipped With Certain Pratt & Whitney PW306B Engine Nacelles

This amendment adopts a new airworthiness directive (AD), applicable to certain Dornier Model 328-300 series airplanes, that requires a one-time inspection of the anti-ice tubing in the engine nacelle at the joint between the anti-ice tubing adapter and duct, and also between the joint of the anti-ice shutoff valve and the same duct, to detect any air leakage at the joints. This action is necessary to prevent an uncommanded engine shutdown in a critical phase of flight due to leakage of air from a loose clamp on the anti-ice tubing joint. This action is intended to address the identified unsafe condition.