On Saturday, the Federal Aviation Administration (FAA) ordered the temporary grounding of approximately 171 Boeing 737 MAX 9 airplanes one day after an emergency exit seal, known as a door plug, blew out of one operated by Alaska Airlines mid-air.

An Emergency Airworthiness Directive now requires operators to conduct a four-to-eight-hour inspection before further flights can go ahead.

Alaska Airlines had already grounded its entire fleet of 65 Boeing 737 MAX 9 aircraft for inspection.

Flight 1282 bound for Ontario contained 171 travelers and six crew members when it made its miraculous safe landing in its take-off location of Portland International Airport.

Passengers were reportedly preparing for the worst, including by saying their familial goodbyes, after the oxygen masks deployed as the pressure dropped inside in response to the massive hole in the fuselage.

The aircraft was hurtling through the air at around 440 miles per hour (708 kph), according to flight tracking website FlightAware.

The passengers had a right to be concerned. "Because of the pressurization of the aircraft and speed, if the pressure vessel fails in a scenario like this, it would fail catastrophically," one aerodynamicist told The Register.

By luck, only the aisle seat of row 26 was occupied, but the speed of decompression caused materials such as headrests, electronics, and even a child's clothes to fly out the hole, according to various reports and accounts.

Although several passengers experienced injuries requiring medical attention, the airline stated all had been medically cleared by late Saturday.

Alaska Airlines revealed the airplane involved in Flight 1282 had only been with the company a little over two months.

The FAA characterized the January 5 incident as "an in-flight departure of a mid-cabin door plug, which resulted in a rapid decompression of the airplane." The agency said the incident could "result in injury to passengers and crew, the door impacting the airplane, and/or loss of control of the airplane."

"The FAA is issuing this AD because the agency has determined the unsafe condition described previously is likely to exist or develop in other products of the same type design," the regulator added.

FAA administrator Mike Whitaker said the organization was assisting a National Transportation Safety Board (NTSB) investigation.

The NTSB released a video of the aircraft, minus the door plug, undergoing inspection.

The missing door plug was eventually
found in the backyard of a Portland school teacher named Bob.

NTSB chair Jennifer Homendy revealed the airplane was already not being used in long hauls over water due to a pressurization warning light that had gone off during three separate flights since December 7.

She called it "a concern" but stated it was not known if the pressurization light issue was related to the door plug failure. The trouble with the warning light system was yet to be fully resolved and instead had been reset.

Homendy expressed frustration at the absence of flight data recorder (FDR) and cockpit voice recorder (CVR) data. That data was erased two hours after the incident, a point at which recording restarts automatically on the devices and previous data is subsequently erased.

"The NTSB has many times talked about the need to increase the time on CVRs from two hours to 25 hours which is consistent with Europe and many other countries," Homendy lamented.

"The FAA thankfully has taken some recent action to issue a notice of proposed rulemaking to extend CVR time from two hours to 25 hours but only on newly manufactured aircraft so it would not affect this," she added.

The NTSB chair said that most planes in service have a lifespan of 40 to 50 years and therefore only extending CVR times in new planes does not do enough to facilitate investigations.

What was quickly recoverable, however, were two cellphones, or so it would appear. One was found in a backyard, the other by a road.

The iPhone found by the side of the road passed its unintentional 16,000 foot drop test perfectly intact within its protective hard case, still in airplane mode, according to one person. It did, however, feature a broken-off charger plug inside of it from when it was "yanked" out through the hole in the fuselage.

By Sunday evening, Alaska Airlines had cancelled 160 total flights, affecting roughly 23,000 travelers on Saturday. An additional 170 were cancelled on Sunday and 60 on Monday. Cancellations are expected to last until at least midweek, said Alaska Airlines.

Boeing has released several updates on the matter.

"Safety is our top priority and we deeply regret the impact this event has had on our customers and their passengers," the company said on Saturday.

"We agree with and fully support the FAA's decision to require immediate inspections of 737-9 airplanes with the same configuration as the affected airplane. In addition, a Boeing technical team is supporting the NTSB's investigation into last night's event. We will remain in close contact with our regulator and customers."

Boeing will host "a company-wide webcast focused on safety" on Tuesday. ®

https://www.theregister.com//2024/01/08/boeing_737_max_9_airplanes/