WASHINGTON—The FAA is working with Boeing to finalize an inspection order on higher-time 737NGs after cracks were discovered in fuselage frames and related parts on three 737-800s being converted to freighters.
The directive is expected to require inspections within a week for aircraft with 30,000 or more cycles, a source with knowledge of the situation tells Aviation Week. Aircraft with between 22,600 and 30,000 cycles face checks within 1,000 cycles, the source added.
The checks can be done visually and are not expected to disrupt operations.
The issue is cracking on left and right-side outboard chords at fuselage station 663 frame fitting and failsafe straps, an FAA notification to other regulators said. The aircraft had between 35,570 and 37,330 flight cycles, the note said.
Boeing analyzed the damage and its maintenance procedures and determined its prescribed inspections “do not provide adequate detection for the subject cracking,” the FAA notice, sent Sept. 27, said. “Boeing is developing repair instructions and working to produce spare parts.”
Boeing said that “no in-service issues have been reported” linked to the cracking. “Over the coming days, we will work closely with our customers to implement a recommended inspection plan for certain airplanes in the fleet,” it added.
The FAA confirmed that an AD is in the works.
The global 737NG fleet totals about 6,600 aircraft, including 1,900 that operate in the U.S.
The cracking issue does not affect the 737-800ERX-derived military use P-8 Poseidon, because none have accumulated enough hours. The MAX fleet is not affected due to differences in the model’s design.