The FAA has issued a notice of proposed rulemaking (NPRM) regarding the adoption of an airworthiness directive (AD) that would require wing spar inspections on nearly 20,000 Piper aircraft. According to the FAA, the AD comes after an investigation into the report of a fatigue crack on a Piper PA-28R-201 “revealed that repeated high-load operating conditions accelerated the fatigue crack growth in the lower main wing spar cap.” The FAA also noted that the area where the crack was found was “inaccessible for a visual inspection.”
The proposed AD would cover PA-28 and PA-32 aircraft with wing spar structures similar to the PA-28R-201. It would apply to aircraft that have 5,000 or more hours time-in-service (TIS), have had a main wing spar replaced with a spar with more than zero hours TIS or have missing or incomplete maintenance records. The AD would require “calculating the factored service hours for each main wing spar to determine when an inspection is required, inspecting the lower main wing spar bolt holes for cracks, and replacing any cracked main wing spar.”
The FAA estimates that 19,696 U.S.-registered aircraft would be affected. According to the administration, the inspection would take approximately 1.5 hours and cost $147.50 per wing spar. Estimated cost of replacing a wing spar is $8,260 per spar.
The proposed AD is an interim action. The FAA has stated that it could initiate further rulemaking based on the data gathered by inspection reports. The AD is open for comments until Feb. 4, 2019. Comments can be made and the complete text of the proposed AD (FAA-2018-1046) can be viewed at regulations.gov.