On Sunday, the U.S. Federal Aviation Administration (FAA) issued a statement stating that it recommended that Boeing (BA.US) 737-900ER models be inspected to ensure that the doors are installed correctly. Previously, some airlines reported unspecified problems with the bolts during inspections.
At present, the FAA has grounded 171 Boeing 737 MAX9 aircraft. The reason is that an Alaska Airlines (ALK.US) Boeing 737 MAX9 passenger aircraft had an accident in the air on the 5th. A door plug (embedded emergency door) on the side of the cabin fell off, and the aircraft made an emergency landing.
The statement said that the focus of the inspection was the door plug in the middle of the aircraft. The 737-900ER model uses the same door plug design as the 737 MAX9 model that had a previous door fly-out accident. The 737-900ER model is currently used by many airlines around the world.
"We fully support the FAA and our customers in taking this action," a Boeing spokesman said in an email.
Alaska Airlines and United Airlines (UAL.US), the only two airlines in the United States that use the 737 MAX9, said this month that during preliminary inspections, they found loose parts on multiple grounded 737 MAX9s. They have had to cancel thousands of flights this month due to the grounding.
United Airlines said on Sunday that it would extend the cancellation of 737 MAX 9 flights until January 26. Both airlines said they have begun inspecting door jams on their 737-900ER fleet.
United operates 136 737-900ER aircraft and expects the aircraft "to be inspected over the next few days with no disruption to our customers."
Alaska Airlines said its inspections began a few days ago and "no findings have been found to date, and inspections of the remaining 737-900ER fleet are expected to be completed without disrupting operations."
Delta Air Lines (DAL.US), which also operates the 737-900ER, said it has "chosen to take proactive steps to inspect our 737-900ER fleet" and does not expect any impact to operations.
The Boeing 737-900ER has more than 11 million hours of operation and more than 3.9 million flight cycles. The FAA said there have been no problems with the door jams on this model. The door jam problem occurred with the 737MAX9, a new aircraft that has flown less frequently.
On Wednesday, the FAA said inspections of the first 40 Boeing 737 MAX 9 aircraft had been completed, a key obstacle to the eventual grounding of the aircraft. The FAA is continuing to review data from these inspections.
The agency said the 737 MAX 9 will "remain grounded until the FAA is confident they can safely return to service."