[aviation news]
Inadequate training, guidance, and oversight on the part of the Boeing Company are to blame for the loss of the door plug from an Alaska Airlines Boeing 737 Max 9 in January 2024.
On Tuesday, the National Transportation Safety Board (NTSB) held a lengthy hearing to discuss the investigation into the event. The FAA was also cited for ineffective oversight of Boeing’s known recordkeeping issues.
The NTSB released a draft of the probable cause of the accident and said the in-flight separation of the left mid-exit door (MED) plug was due to Boeing’s failure to provide adequate training, guidance, and oversight necessary to ensure manufacturing personnel could consistently and correctly comply with its parts removal process, which was intended to document and ensure that the securing bolts and hardware that were removed from the left MED plug to facilitate rework during the manufacturing process were reinstalled.
The NTSB said that contributing to the accident was the FAA’s ineffective compliance enforcement surveillance and audit planning activities, which failed to adequately identify and ensure that Boeing addressed the repetitive and systemic nonconformance issues associated with its parts removal process.
“We at Boeing regret this accident and continue to work on strengthening safety and quality across our operations,” a Boeing spokesperson told FLYING on Wednesday. “We will review the final report and recommendations as we continue to implement improvements.”
The FAA provided its own statement to FLYING responding to the hearing.
“The FAA takes NTSB recommendations seriously and will carefully evaluate those issued today,” the agency said. “The FAA has fundamentally changed how it oversees Boeing since the Alaska Airlines door-plug accident and we will continue this aggressive oversight to ensure Boeing fixes its systemic production-quality issues. We are actively monitoring Boeing’s performance and meet weekly with the company to review its progress and any challenges it’s facing in implementing necessary changes.”
The event happened at dusk, and soon social media channels were flooded with images shot from inside the airliner showing oxygen masks hanging from the ceiling and the city lights of Portland, Oregon, seen through a gaping hole in the fuselage as the aircraft returned to Portland International Airport (KPDX).
The hearing, which took place in Washington, D.C., and lasted more than five hours, began with a review of the event.
The jet, operating as Alaska Airlines Flight 1282, was approaching 14,830 feet when the door plug ejected from the fuselage, resulting in an explosive decompression. The door, along with unsecured objects including cell phones, paper, children’s toys, clothing, and parts of the aircraft interior, rained down on a Portland suburb. There were injuries, but no fatalities among the 177 people on board.
It was noted that no one was sitting in the row where the door plug was located. Images of the seats show mangled frames, as the force of the decompression was so great it tore the armrests off. One of the more chilling statements came from an interview with a member of the cabin crew who said when they saw the hole in the airplane and the twisted seats, they initially feared some passengers had been lost.
The NTSB investigation revealed the door plug, which was not intended to be an exit on this aircraft, was missing four critical installation bolts. It was revealed that the door plug had been moving in the installation track because it lacked the bolts until the accident flight, where the forces were such that the door was pulled up out of the track and away from the aircraft. Investigators stressed that the flight crew performing the preflight exterior inspection would have no way of knowing the door plug bolts were missing.
The fuselage with the door plug installed was built in Kansas at Spirit AeroSystems and then brought by rail to Boeing’s Renton, Washington, plant for final assembly. The arrival inspection of the fuselage revealed a number of rivets had been improperly installed. In order to make repairs, the door plug had to be removed. The door plug is an option on the aircraft—the space can be configured as a door, or, as in the case of Flight 1282, it is a window inside the cabin.
“Do we know who opened and closed the door plug?” NTSB Chair Jennifer Homendy asked rhetorically during the hearing.
The answer was “no” because there was no documentation on the removal or the reinstallation. If there had been documentation of the door plug removal and subsequent reinstallation, this would have alerted inspectors to the need to double-check the reinstallation of the door plug.
“It was a nonroutine task,” said NTSB investigator Nils Johnson.
That prompted this question from NTSB member J. Todd Inman: “Is nonroutine the greatest place to inject risk into the process?”
Johnson replied: “I would agree with that. Failure to document is very hard to detect.”
Homendy expressed concerns about reports of a lack of formal training on door removal at the time of the accident. The investigation included interviewing Boeing technicians who reported their training had been informal and on the job. One of the factors that was repeatedly mentioned during the hearing was that the OJT was cultural, and the lack of experienced factory workers made the quality of training suspect, as a poorly or incompletely trained worker could be training someone else.
Another surprise from Tuesday’s hearing was that, according to NTSB investigators, had even just one door plug bolt been installed, it would have been enough to keep it from departing the aircraft.
It was noted that since the accident there has been a redesign of the door plugs to ensure and verify the bolts are in place, including adding lanyards. The new part needs to be certified by the FAA, but once this is done, Boeing will issue a service bulletin to operators of its aircraft to install the new part, and it is likely the agency will be asked to issue an airworthiness directive (AD) to verify the integrity of bolts in the active fleet.
Since the accident, the door plugs on other Boeings in service were inspected. There were no missing bolts, however, a few bolts were not torqued to specification.
Investigators stated that the previous three pressurization issues reported by crews who flew that airframe were not a factor in the accident. According to the testimony, the pressurization issues were traced to a faulty microswitch. After the third event, the airline removed the aircraft from over-ocean flight and scheduled it for maintenance. The accident flight was the last one before the aircraft was to go in for repairs.
Questions About Boeing Safety Culture
Since the beginning of the investigation, authorities have focused on what has been described as a lacking safety and quality control culture at Boeing.
This resulted in the agency working with the aerospace giant to develop a better safety culture, including a safety management system to prevent future mishaps. Boeing leadership was placed under scrutiny, which resulted in a shakeup of C-suite executive leadership, and the company’s manufacturing processes have also been under a microscope.
Doug Brazy, an engineer with the NTSB, testified that as a result of the accident, there has been a significant increase in scrutiny of Boeing’s production process by the NTSB, FAA, and the company’s customers.
Flight Crew Praised
There were numerous comments expressing admiration for the flight crew for the way they handled the emergency.
When the cockpit door was forced open by the violent decompression, it yanked the headset off the pilots, and the noise was so loud they had to communicate by yelling and hand gestures as they ran emergency checklists, declared an emergency, and returned to Portland.
NTSB investigator Starr Blum explained that pretakeoff, the flight crew had briefed an emergency return to Portland, as this is standard operating procedure.
“They talked about a return plan, returning to Runway 28L,” Blum said.
Children On Board
Among the passengers on board were three infants under the age of 2 who were being held in their caregiver’s lap, which is legal as long as the caregiver is an adult. There were several mentions about the accident bringing up the issue of the wisdom of holding children instead of having them secure in age-appropriate seats.
NTSB member Thomas Chapman asked how close those children were to the door plug. He was told they were five or more rows away, and none sustained physical injuries.
CVR Overwritten
Several people testified that the cockpit voice recorder (CVR) in the aircraft was not available during the investigation, as by the time the technicians returned to the cockpit, it had overwritten itself, as it is designed to record two hours at a time, then recycle. The procedure in the event of an accident or incident is to pull the circuit breaker to preserve the information on the CVR, but as was noted, the flight crew was focused on the welfare of the passengers.
One of the recommendations to come out of the NTSB investigation was to require CVRs capable of recording 25 hours at a stretch before the overwrite.
The hearing concluded with a lengthy list of recommendations aimed at Boeing and the FAA to address “ineffective oversight and inadequate quality escape mitigation.”
Additionally, there were recommendations for Alaska Airlines to address safety issues discovered during the investigation, such as a need for more realistic scenario-based training for aircraft-specific training and procedures for flight crews in the use of portable oxygen bottles and insufficient hands-on, aircraft-specific training and procedures for flight crews’ use of each oxygen system in an operator’s fleet. There were also recommendations for the need to prevent the loss of CVR audio and to study the potential for injury for lap-held children under the age of 2.
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