United Airlines said Monday that it found loose screws during inspections of its 737 Max 9 fleet after a door plug flew out of an Alaska Airlines plane over the weekend.
United won't say how many planes had loose screws.
“Since we began preliminary inspections on Saturday, we have found instances that appear to be related to installation problems in the door stopper – for example, screws that needed to be tightened even further,” United said in a statement. “These findings will be addressed by our tech ops team to safely return the aircraft to service.”
After the Alaska Airlines incident, the Federal Aviation Administration grounded all 737 Max 9s.
“The FAA’s top priority is to ensure the safety of the flying public,” it said in a statement. “We have grounded the affected aircraft and they will continue to be grounded until the FAA is satisfied they are safe.”
United said it had to cancel 200 Max 9 flights on Monday as a result of emergency inspections and expects “significant cancellations” on Tuesday as well.
NTSB investigators have recovered the door plug from Alaska Airlines' Boeing 737-9 MAX Flight 1282, which was found in the backyard of a home in Portland, Oregon.NTSB
In response to United's findings, Boeing issued a statement Monday evening saying, “As operators conduct the necessary inspections, we are in close contact with them and will assist in addressing any findings.” ensures that every Boeing aircraft meets design specifications and the highest safety and quality standards. We regret the impact this has had on our customers and their passengers.”
The National Transportation Safety Board, which is investigating the incident involving the Alaska Airlines flight near Portland, Oregon, has not yet commented on United Airlines' announcement.
NTSB investigators recovered the door plug that fell off Alaska Airlines Flight 1282 on Sunday, giving them the key piece of evidence they are examining with a lab microscope.
The 26-by-46-inch, 63-pound plug was discovered intact in the backyard of a teacher's home in Portland on Sunday evening, according to NTSB officials.
The part fell from the plane, a Boeing 737 Max 9, around 5:11 p.m. local time on Friday as the plane carrying 171 passengers, including three babies and four unaccompanied minors, climbed to 16,000 feet after takeoff from Portland International Airport, according to the NTSB .
NTSB investigators have recovered the door plug from Alaska Airlines' Boeing 737-9 MAX Flight 1282, which was found in the backyard of a home in Portland, Oregon.NTSB
The door plug is used to close unused exits on aircraft and is attached to the aircraft with a series of bolts, cables, hinges and bump stops, according to a diagram published by the NTSB.
The mid-air incident caused an “explosive decompression” of the Alaska Airlines plane and caused the flight crew to immediately return to Portland with a gaping hole in the side of the jet, according to the NTSB.
No one was injured in the incident. But NTSB Chairwoman Jennifer Homendy told reporters that if the incident had occurred at 30,000 feet, “something much more tragic could have occurred.”
During a news conference Sunday evening, Homendy said the door plug's dislodgement caused a violent and chaotic situation in the plane's cabin, sucking the headrests, at least one tray table and two cellphones out of the hole in the plane.
Homendy said the incident also ripped open the cockpit door and sucked out a laminated quick-reference checklist that pilots use.
“The laminated checklist flies out the door. The captain takes the short manual and hands it to the first officer. They start going through their memorabilia items,” Homendy said.
She said the sudden decompression also ripped off the first officer's headset and part of the captain's headset.
“You have your [oxygen] “Masks on, turned on the speaker so they could communicate with the people in the booth,” Homendy said.
She said the incident also caused damage to rows 1 to 33 of the aircraft.
The investigation also revealed three previous incidents on the Alaska Airlines aircraft in which the automatic pressurization error indicator illuminated during flights on December 7, 2023; Jan. 3 and 4, Homendy added.
“On these previous flights, after the light came on, they flipped the switch to alt mode, which is normal. There is a backup. It was very harmless. Nothing happened,” said Homendy.
She said it remains unclear whether there is a connection between the automatic pressure indicator light coming on and the door plug burning out. She said Alaska Airlines prevented the plane from being flown over water to Hawaii and limited it to overland operations “so it could quickly return to an airport if some light came on.”
Homendy said that although the cockpit voice recorder (CVR) was recovered from the aircraft, it did not contain any useful data as it was programmed to reset and re-record every two hours.
“So we have nothing from the CVR,” Homendy said.
She said investigators are closely examining the door stopper and frame from which it was blown out, as well as any components used to hold it in place, to determine what caused the incident. She said the investigation also included interviews with the six-member flight crew and passengers.