The FAA has adopted an airworthiness directive to correct possibly ineffective sealing of firewall-penetrating wiring on Pacific Aerospace Limited Model 750XL aircraft, a 10-place, single-engine utility turboprop that is capable of extremely short takeoffs and landings.
The AD, which takes effect August 19, was prompted by action taken by the Civil Aviation Authority of New Zealand and will “mandate the instructions in Pacific Aerospace Mandatory Service Bulletin (MSB) PACSB/XL/101 issue 1, dated 9 May 2018, or later approved revision, to improve the firewall sealing by installing new components (firewall penetration tubes, fire sleeve and hose clips).”
Twenty-two aircraft of U.S. registry are believed to be subject to the AD with an estimated cost of compliance calculated as $1,065 per aircraft. “According to the manufacturer, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals,” the FAA said.
The FAA filed notice of its intention to implement the AD in 2019 and received no comments from the public before publishing its final order on July 30.