US investigators retrieve a 737 MAX jet panel. After American officials found a panel that had blown off an Alaska Airlines (ALK.N.) 737 MAX 9, the examination of grounded Boeing aircraft was resumed on Monday, ending a delay caused by worries over the problematic jet program.

The identical type of panel, which weighs around 60 pounds (27 kg) and covers an optional exit door, was put on 171 Max 9 aircraft, but it came off the aircraft on Friday. The U.S. Federal Aviation Administration has ordered the temporary grounding of these aircraft to inspect them.

However, examining a portion of the remaining fleet over the weekend avoided the normal process of regulatory clearances, delaying inspections until airlines had received specific orders.

As per the earlier story by Reuters, Boeing confirmed on Monday that it had provided the document to airlines. After receiving FAA approval, the inspections—which the agency had previously estimated would take four to eight hours per plane—can begin. According to someone with knowledge of the situation, permission was granted. The FAA chose not to respond.

On Friday (ALK.N), after departure from Portland, Oregon, on the way to Ontario, California, the door stopper broke off, depressurizing the aircraft and compelling the pilots to make an unplanned U-turn.

The aircraft, carrying six crew members and 171 passengers, landed safely. Chair of the U.S. National Transportation Safety Board (NTSB), Jennifer Homendy, revealed that the panel was located in the backyard of a Portland school teacher known only as “Bob” in the Cedar Hills area on Sunday. She termed it a “key missing component” to figuring out why the tragedy happened, so she was “very relieved” to find it.

Our structural team will examine every aspect of the door, including witness markings, paint transfers, and its state at the time of discovery. That can reveal much to them about what happened, “added the speaker.

Homendy stated that it must have been a “terrifying event” because the force from the panel loss was significant enough to blow open the cockpit door during the flight.

“They heard a bang,” Homendy remarked of the pilots, whom researchers questioned. Homendy said that because the voice recorder in the cockpit had been wiped, no data had been recorded. She urged authorities once more to require retrofitting already-built aircraft with recorders that capture 25 hours of data rather than the current two hours needed in the United States. Boeing’s stock dropped almost 8% as traders processed the latest blow to the aircraft manufacturer. The corporation will lose more than $12.5 billion in value if the losses continue, nearly equal to the cost of creating a new aircraft.

The accident occurred at the same time as Spirit AeroSystems (SPR.N), a supplier to Boeing and the panel, is dealing with continuous production setbacks that are impeding their ability to recover from the previous, protracted 737 MAX safety grounding and the more considerable disruption caused by the pandemic.

In the months since the 737 MAX was grounded in March 2019, Airbus shares have increased by 25%, while Boeing’s shares have decreased by over 40%. Spirit Aero’s stock dropped 8% in the late-morning New York trade. The only other American carrier operating the planes, United Airlines (UAL.O.), saw a 2% increase in shares, while Alaska Airlines’ shares sank 5% overall.

PLANES DECLINED

The Boeing MAX 9 fleet, including airplanes flown by other airlines, including United, will remain grounded until the FAA is satisfied that they are secure, the agency announced on Sunday. According to data from the aviation analytics company Cirium, 144 of the 171 aircraft the directive applies to are flying in the United States. Turkish Airlines, Aeromexico, and Copa Airlines of Panama were grounding the impacted aircraft.

Despite having different characteristics from the Alaska Airlines aircraft, three 737 MAX 9 aircraft operated by Lion Air were temporarily grounded, according to a statement released by Indonesia’s transport ministry on Monday.

Many in the industry assumed the planes could swiftly return to service after the FAA announced on Saturday that the necessary checks would take four to eight hours.

However, according to people familiar with the situation, the FAA and Boeing have not yet agreed on the requirements for the checks. Therefore, airlines have not yet received comprehensive instructions. The FAA must accept Boeing’s inspection standards before the inspections are finished and the aircraft is cleared to take off again.

Late on Sunday, Alaska Airlines announced that it had not received any instructions from Boeing. The airline indicated that travel problems will likely continue until midweek after canceling 170 flights on Sunday and an additional 60 on Monday. United grounded its 79 MAX-9 aircraft on Sunday, canceling 230 flights, or 8% of its planned departures.