Several new ADs affect Pacific 750XL

An AD published August 13 requires inspection of the flap screw jack assembly to determine if the instructions included in the aircraft maintenance manual, which contained erroneous information prior to its revision in June 2019, were followed. Two instances of incorrect flap screw jack assembly installation prompted a mandatory service bulletin in August 2019. Aviation authorities in New Zealand issued an AD in September 2019, and the FAA has followed suit.

The FAA estimates the cost of compliance will include a one-hour inspection of each aircraft, at a cost of $85; aircraft found to have an unsafe assembly will then require an additional four hours of labor, and replacement parts, for a total cost of $390 per aircraft to complete the necessary repair. Pacific Aerospace told the FAA that some costs may be covered under warranty, the AD notes. The FAA also noted that incorrect installation of the screw jack might inhibit full extension of the flaps, which could in turn affect approach and landing performance, and extend the landing distance. This could culminate in a runway overrun.

The FAA previously published an AD for the same aircraft on July 30, but addressing a different issue: possible ineffective sealing of the firewall.

Four more directives followed on August 17 and 18, mandating a range of actions including compliance with a Pacific Aerospace Mandatory Service Bulletin issued in 2019 that addresses an unsafe condition resulting from the close proximity of flap and fuel controls. Another AD published August 17 requires inspection of the nose landing gear assembly and possible action to correct a defective assembly.  Another AD published on August 18 and effective September 22  supplements a previous directive requiring revisions to the airplane flight manual to clarify the procedure for replacing the low oil pressure warning light. Finally, an AD published on August 18 that is effective September 7 mandates installation of retaining washers to prevent malfunction of the ailerons. 

The addresses and deadlines to submit comments for each of the six ADs issued on or after July 30 are included in the each of the respective online documents, and formal comments may also be submitted online.

The 750XL is a 10-place, single-engine turboprop capable of extremely short takeoffs and landings.