U.S. aviation agencies are investigating whether bolts were missing in the Alaska Airlines door panel burst incident, and 171 U.S. planes and dozens of other countries are currently grounded for inspection. Federal investigators said that a Alaska Airlines airliner last week had its door panel detached after takeoff, and they were investigating whether the four bolts used to secure the door panel when the plane took off were missing, CBC reported.
The plug covering the location of the emergency door fell off the plane as Alaska Airlines Flight 1282 flew 4,800 meters over Oregon Friday night.
The roller guide on the top of one of the plugs is broken. Jennifer Homandy, chairman of the National Transportation Safety Board, said the safety committee is investigating whether the four bolts that helped prevent the panels from sliding on the wheels as the plane took off from Portland were missing, or whether they exploded "during a violent, explosive decompression event."
The National Transportation Safety Board's comments on Monday come shortly after Alaska Airlines and United Airlines separately reported that they had found loose parts in the panels or door plugs of some other Boeing 737 Max 9 jets.
"Since we began our initial inspection on Saturday, we've found a number of conditions that appear to be related to door plug installation issues, for example, bolts that require additional tightening," Chicago-based United Airlines said. Alaska Airlines said that when it began inspecting the Max 9, "initial reports from our technicians indicate that some loose hardware can be seen on some aircraft." and visible to the naked eye".
The findings of investigators and airlines are mounting pressure on Boeing to address growing concerns since the horrific airframe explosion. Boeing held an all-staff online meeting on Tuesday to discuss safety issues. The company has had problems with various aircraft in recent years, and the company promises to "help solve all the problems found."
Boeing has delivered more than 200 Max 9 aircraft to customers around the world, but 171 of them were grounded by the Federal Aviation Administration on Saturday. Airlines in several other countries have also grounded the 737 Max 9 aircraft. No Air Canada uses the Max 9.
Missing hatch panels were found in the backyard of a school teacher's home near Portland on Sunday. NTSB officials said it would be sent to the agency's Washington, D.C.-based lab for detailed study, which could help pinpoint the cause of the bolt loosening. Alaska and United Airlines have canceled hundreds of flights since the weekend due to grounding of aircraft.
Alaska Airlines has 65 Max 9s and United Airlines has 79. It wasn't until Monday that Boeing and the Federal Aviation Administration completed instructions on how to inspect their aircraft. The aircraft that had the accident on Friday was brand new and had been put into service in November. The airline has halted flying across the Pacific Ocean and to Hawaii after the cabin pressurization system warning lights were turned on on three flights.
But some aviation experts questioned why Alaska Airlines continued to use the aircraft on land routes with pressurization warnings. However, Homandy said Monday that the National Transportation Safety Board had found no evidence that the warnings were related to the door stopper burst. The Max is the latest version of the Boeing 737, a twin-engine, single-aisle aircraft that debuted in the late 60s of the 20th century and has undergone several updates.
The 737 has long been the workhorse of airlines on U.S. domestic routes. On Monday, Boeing shares fell 8 percent, and Spirit AeroSystems, which fits door plugs for the Max 9 aircraft, fell 11 percent.