US investigation under way into how section of new Boeing 737 Max blew out mid-flight

Federal Aviation Administration in US orders temporary grounding of 737 Max 9s operated by US airlines or in US territory

Federal investigators in the US have launched an investigation into how a section of a new Boeing 737 Max blew out mid-flight as airlines in Turkey and Panama grounded their planes for inspection.

The withdrawals come after the US airline regulator, the Federal Aviation Administration (FAA), on Saturday ordered the temporary grounding of some 737 Max 9s operated by US airlines or in US territory.

All 171 passengers and six crew of the Alaska Airlines-operated Boeing plane landed back safely at Portland, Oregon, after the incident on Friday night, but the outcome could have been much worse, according to investigators.

“We are very fortunate this didn’t end up in something more tragic,” Jennifer Homendy, the head of the National Transportation Safety Board, said at a press conference in Portland late on Saturday.


While there had been reports of only minor injuries, “I imagine this was a pretty terrifying event”, Ms Homendy said. “We don’t often talk of psychological injury, but I am sure that occurred here. We have been told it was a very chaotic scene. Very loud.”

She said the incident happened at about 16,000ft rather than at cruising altitude and only 10 minutes into the flight.

No one was seated in the two seats next to the deactivated exit cabin door that blew out, leaving a gaping hole in the fuselage of the plane. While often used as an additional exit on more densely configured lower-cost carriers, the door is permanently plugged on Alaska Airline planes. Passengers seated on the inside see only a window.

An identical door on the other side of the aircraft remained intact, Ms Homendy said. Investigators would look at maintenance records, the pressurisation system and the door components.

She said the investigation was focused on the Alaska Airlines incident rather than more broadly on Boeing’s Max fleet, while noting: “We’ll go where the investigation takes us.”

With the aircraft being just two months old, investigators would look “in great detail at the assembly records and quality assurance inspections of that part of the airplane”, said John Cox, a retired pilot and chief executive of Safety Operating Systems, an aviation safety consultancy in the US.

Meanwhile, the plane was not being used for journeys to Hawaii after a warning light that could have indicated a pressurisation problem lit up on three different flights, a US official said.

Alaska Airlines decided to restrict the aircraft from long flights over water so that the plane “could return very quickly to an airport” if the warning light reappeared, said Jennifer Homendy, chair of the US National Transportation Safety Board (NTSB).

Ms Homendy cautioned that the pressurisation light might be unrelated to Friday’s incident in which a plug covering an unused exit door blew off the Boeing 737 Max 9 as it cruised about three miles over Oregon.

The warning light came on during three previous flights: on December 7th, January 3rd and finally on January 4th, the day before the door plug broke off.

The incident is a blow to Boeing, which has struggled with manufacturing defects on the 737 Max. It continues to experience the fallout from a 20-month worldwide grounding imposed by regulators after a pair of deadly crashes five months apart.

The US plane maker said in a statement on Saturday that it supported the temporary grounding. “Safety is our top priority. We agree with and fully support the FAA’s decision to require immediate inspections of 737-9 aeroplanes with the same configuration as the affected aeroplane.”

There are 215 Max 9 aircraft in service globally, according to data from aviation consultancy Cirium. The biggest operators are United Airlines and Alaska Airlines in the US, Turkish Airlines and Copa Airlines of Panama.

Copa said it had temporarily suspended flights of 21 Boeing 737 Max 9 jets. Turkish said it had withdrawn its small fleet of five Max 9 aircraft.

Alaska Airlines cancelled 21 per cent of its flights on Sunday, while United cancelled 8 per cent, according to flight data website FlightAware. Copa and Aeroméxico reported cancellations of 14 and 11 per cent respectively.

The European Union Aviation Safety Agency said it had adopted the FAA’s emergency directive but that this was a “precautionary measure as we understand from both the FAA and Boeing that no European airlines in EASA member states currently operate an aircraft in the affected configuration”. - Additional reporting from PA

Copyright The Financial Times Limited 2024

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