The U.S. Federal Aviation Administration (FAA) has issued two new Airworthiness Directives (ADs) that could impact up to 21,000 Piper aircraft. The proposed ADs, published in September 2024, aim to address safety concerns related to the main wing spars of Piper models. The FAA is accepting comments on the directives until November 7, 2024.
The new directives, AD 2024-00008-A and AD 2024-00033-A are based on findings from mandatory eddy current inspections of Piper wing spars under a previous directive. The inspections revealed issues such as cracks, deep scratches, gouges, and thread marks in the bolt holes of the wing spars. The latest ADs call for repetitive inspections and corrective actions, including modifications or replacements of the main wing spars.
In collaboration with the FAA, Piper Aircraft conducted further inspections and found that residual stress from the spar cold bending process contributed to fatigue in the critical bolt-hole area. As a result, Piper has redesigned its wing spar assembly and developed a reinforcing kit for several models, including the Cherokee, Warrior, Archer, and Piper Pilot. The new spar design and reinforcement kit will extend inspection intervals and the life limit of reinforced spars to 25,000 hours, compared to 12,000 or 13,499 hours for unmodified spars.
The Aircraft Owners and Pilots Association (AOPA) has been closely monitoring the directives. Murray Huling, AOPA’s Vice President of Regulatory Affairs, expressed cautious optimism: “We’re pleased that Piper has introduced a reinforcing kit and spar replacement option, which will reduce the inspection burden and address the original defect. However, given the complex risk assessment formula and the large number of affected aircraft, we’ll carefully review the directives before submitting formal comments.”
The FAA and Piper Aircraft are committed to ensuring the continued safety and airworthiness of these aircraft through proactive inspections and structural improvements.
Reference: https://flyer.co.uk/piper-wing-spars-facing-new-airworthiness-inspections/
