(New York) The incident on Friday involving a Boeing 737 MAX 9 that lost a door in flight in the United States and the resulting grounding of aircraft around the world are a new blow for the manufacturer, even if experts expect limited impact.

The American Federal Civil Aviation Agency (FAA) on Saturday requested the immobilization for inspection of some 171 aircraft of this model, notably affecting companies such as United Airlines, Turkish Airlines and Aeromexico.

On Friday evening, a door came off a 737-9 after takeoff from Portland, Oregon, on a domestic Alaska Airlines flight, while the plane had 171 passengers and 6 crew members on board. was at an altitude of almost 5000 m.

The spectacular images of the incident, which left only minor injuries, showing a gaping hole in the sky, went around the world.

The investigation by the American agency responsible for transportation safety, the NTSB, has just begun and no conclusions have yet been drawn from this malfunction.

This comes in addition to a whole series of setbacks that the Arlington (Virginia) group has experienced in recent years, particularly concerning this model of device.

The most serious of these were the crashes of two 737 MAXs, in October 2018 in Indonesia and March 2019 in Ethiopia, which caused the deaths of a total of 346 people.

After these accidents, linked to the MCAS piloting software, all 737 MAXs were grounded for 20 months.

But the American manufacturer has also suspended, on several occasions, for almost two years in total, deliveries of its long-haul 787 for manufacturing and inspection defects.

More recently, it was once again the 737 MAX that made headlines, after the discovery, in the fall, of faulty workmanship on the rear watertight bulkhead of the aircraft, then in December, of a risk of a loose bolt. on the rudder control system.

In the case of Friday’s incident, the dropout may be linked to the manufacture of the door or the screws, but also to the installation and quality control, explains Scott Hamilton, of the specialist site Leeham News.

“If it’s an installation and quality problem, linked to Boeing or Spirit AeroSystems,” its largest subcontractor, “it’s probably limited,” says the analyst.

“I think it’s more of an exceptional anomaly than a systemic problem,” he says.

“For me, it’s a very isolated problem,” adds Michel Merluzeau, aeronautical sector specialist for the AIR firm. “I don’t see a design problem at all. »

A hypothesis validated, according to him, by the nature of the inspection requested by the FAA, achievable in only 4 to 8 hours, according to the American regulator.

“We should get back to normal in about a week,” according to Michel Merluzeau.

“This is an event that emanates from the problems in the supplier chain and the stress on production in commercial aviation currently,” describes the analyst, who also cites an impact of the coronavirus pandemic.

In spring 2020, Boeing suspended production for almost a month. Faced with the sudden slowdown in air transport, the century-old company laid off some 30,000 people.

Boeing began hiring heavily again in 2022, but many veterans have not returned.

“You have a lot of new people, who have to do their apprenticeships,” says Scott Hamilton.

“Experience is something that is very, very important in this industry,” agrees Michel Merluzeau.

Unlike Boeing, its major competitor Airbus will only have closed a few days in 2020 and avoided massive layoffs, recalls Scott Hamilton.

On the commercial level, “I don’t see any serious long-term impact”, linked to Friday’s failure, anticipates Michel Merluzeau. “Boeing must manage the situation and give, as quickly as possible, guarantees to customers on the assembly of the planes so that there are no worries. »

A scenario also retained by Scott Hamilton, who emphasizes that the MAX 9 is, “essentially, an American aircraft”, two thirds of the aircraft being operated by Alaska Airlines (65) and United (79).

“Their relationship with Boeing is deep and good,” according to the analyst, for whom the soaring door should especially weigh in his relations with regulators.

The manufacturer recently requested an exemption from safety obligations as part of the approval of the MAX 7, linked to a defect in the engine defrosting system.

According to Scott Hamilton, if the findings of the investigation into the Alaska Airlines flight incident attribute blame to Boeing, “that will affect the FAA’s decision on these exemptions.”