Faulty MRO Process Prompts Landing Gear Checks
By Sean Broderick
The FAA will mandate maintenance records checks on several Boeing aircraft types to flag and remove more than 300 improperly repaired main landing gear (MLG) assemblies after the issue was linked to a 767 gear collapse in 2020.
In a notice of proposed rulemaking (NPRM) issued June 20, the FAA said it will order all 767 operators to either check records or inspect MLG outer cylinders for signs of heat damage. Damaged parts must be replaced at a cost of about $500,000, the FAA said. The agency will give operators 30 months from the issuance of a final rule to do the work.
The parts were repaired using a grinder “operating outside of its input parameters,” the FAA said. The work was done at an unnamed maintenance, repair, and overhaul (MRO) provider and implicated in the investigation of an August 2020 Omni Air International left MLG collapse.
The incident took place when the 767-300, on a flight from Kabul, Afghanistan, to Washington, D.C., with a planned refueling stop in Bucharest, Romania, touched down on Bucharest Aurel Vlaicu airport’s runway 07. The left MLG collapsed, and the aircraft skidded to a stop. All 15 crew members and 49 passengers evacuated safely.
The Romania Civil Aviation Safety Investigation and Analysis Authority-led probe determined that the MLG cylinder fractured from damage caused during a 2015 overhaul. The cause: “overheating in the base metal due to the result of an inner diameter grinding machine that was found to be operating outside of input parameters,” the authority’s final report, issued in March, said.
The MRO shop determined the same issue could affect a total of 331 MLG assemblies overhauled using a similar process. The suspect gear assemblies are for 737s, 747s, 757s, and 767s. Investigators said 40 of the gear assemblies, including the Omni one, have both possible damage and no record of any follow-up non-destructive inspections that could flag problems.
Romanian investigators recommended Boeing and the FAA analyze the probe’s findings and related ramifications for the in-service fleet and follow up with any needed actions.
Earlier in 2024, Boeing began issuing what is expected to be a series of fleet-specific instructions on the issue.
“The MRO identified a suspect population of MLG outer cylinders on 737, 747, 757, and 767 airplanes that may have also been affected and provided this information to the FAA and Boeing,” the company said in a February 2024 767 alert requirements bulletin (ARB) outlining the issue. The FAA’s NPRM is based on the 767 ARB and a related service bulletin.
Boeing has also released a bulletin on the 737 fleet, investigators said in the final report on the Omni accident.
Boeing did not immediately respond to Aviation Week queries.
