Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Raytheon airplanes identified above. The existing AD currently requires a visual inspection to determine whether adequate clearance exists between the fan venturi motor casing and the adjacent equipment, and adjustments, if necessary; and a visual inspection to detect signs of overheating, degradation of insulating materials, and ingestion of debris into the motor, and replacement of discrepant parts with serviceable parts. This proposed AD would instead require that operators replace the fan venturi with a new or modified part. This proposed AD is prompted by reports that the fan venturi overheated and produced smoke while the airplane was on the ground. We are proposing this AD to prevent heat and fire damage to equipment adjacent to the fan venturi, which could result in smoke in the cabin and/or burning equipment.