United Airlines and Alaska Airlines have reportedly found loose parts on multiple grounded Boeing 737 Max 9 aircraft.
US regulators grounded 171 Max 9 aircraft after a panel blew off an Alaska Airlines-operated flight shortly after take off from Portland, Oregon, on Friday, forcing an emergency landing.
Alaska Airlines said that initial reports from technicians preparing its 737 Max 9 fleet for inspection indicated “some loose hardware was visible on some aircraft”.
It was waiting for final documentation from Boeing and the US Federal Aviation Administration (FAA) before formal inspections could begin.
“When we are able to proceed with the formal inspection process, all aircraft will be thoroughly inspected in accordance with detailed instructions provided by the FAA in consultation with Boeing,” the airline said.
“Any findings will be fully addressed in a matter that satisfies our safety standards and FAA compliance. The formal inspections will also require documenting all findings and those will be reported to the FAA. No aircraft will be returned to service until all of these steps are complete.”
United, the other US carrier that flies this Boeing model with the panels, said its preliminary checks found bolts that needed tightening on several panels.
A source familiar with the matter told Reuters that United had so far found almost 10 aircraft with loose bolts during its preliminary checks.
United said: “Since we began preliminary inspections on Saturday, we have found instances that appear to relate to installation issues in the door plug – for example, bolts that needed additional tightening. These findings will be remedied by our tech ops team to safely return the aircraft to service.”
Discussions between Boeing, the FAA and the airlines on the precise inspection guidelines are still ongoing.
United said it had cancelled 200 flights as of Monday and expected significant cancellations today.
“We have been able to operate some planned flights by switching to other aircraft types, avoiding about 30 cancellations each on Monday and Tuesday,” the carrier added.