Alaska Airlines 1282 Door Failure in Flight.
On January 5th (2024) an Alaskan Airlines Boeing MAX 9 aircraft lost a blank door section of the fuselage whilst climbing through 16,000 feet after departing from Portland, Oregon, bound for Ontario, California.
The event left an emergency door sized hole in the aircraft and the decompression sucked out seat cushions, the shirt worn by a child near the hole as well as a couple of mobile phones.
The crew initiated an emergency descent and the aircraft returned to Portland without further incident.
The Boeing 737 MAX 9 is a stretched version of the MAX 8 that was involved in two fatal crashes as a result of a system (known as MCAS) that automatically pitched the aircraft nose down if a sensor detected an excessive pitch up angle. There were two major problems with that design. One was that only one sensor was needed to trigger the MCAS pitch controller. Both crashes involved a faulty sensor. Secondly, the system was installed without the knowledge of the pilots or with them having any knowledge of how to turn it off. This is unheard of and along with the lack of a second sensor (redundancy) flies in the face of standard aviation safety practices.
This latest emergency was due to an entirely different failure however. For simplicity, imagine that you are sitting on an aircraft by the wing. You may have seen the overwing emergency exit instructions. They often say something like, pull this red handle and pull the door inwards, rotate it so that you can throw if out of the hole and then exit onto the wing.
The reason you have to pull the door inwards, is that it is bigger than the hole that it covers. This means that it cannot be forced out by increasing internal pressure as the aircraft climbs and pressurises. That is known as a plug type door and is a simple, reliable design used universally for decades in most airliners.
In the case of the Alaskan door failure, it is also referred to as a plug door but it was not the simple type described above but relies on bolts to hold it in place. It was not intended to be used and was covered by the interior trim of the cabin. A usable exit door was an option for higher density seating, which required more exits but Alaskan did not choose that option and so the door should have sat in the hole, unused for the life of the aircraft unless the operator chose to reconfigure it.
Alaskan sensibly grounded all models of the MAX 9 that they had immediately and later the FAA grounded all US registered MAX 9 aircraft for further inspections. Currently they are still out of service, also in two other countries that have airlines with the model in their fleets.
This has now opened a discussion about the future of the MAX range, with some calling for it to be scrapped. The cost of doing that will be huge were it to happen but if the public don’t trust the aircraft it will also have repercussions on the industry anyway. Airlines may be reluctant to buy them when the Airbus neo range has been so successful and trouble free. It was competition from Airbus that prompted Boeing to redesign the 737 and create the MAX initially.
I have written about this in more detail in my book but the MAX crashes caused a huge reaction over the lack of proper oversight on the Federal Aviation Administrator – the regulator – and their decision to allow Boeing to effectively mark their own homework. Now this mess looks likely to create another lengthy process. Subsequent investigations and modifications are supposed to have fixed the problem that crashed the original MAX but it has left a question mark of the whole design philosophy of the MAX 737 range following this recent event.
The original 737 was launched in the 1960s and has been modified into several versions over the years, mostly to install larger, more fuel efficient engines each time. Many feel this constant modification has gone too far and the changes made to accommodate the very big engines for the MAX has exceeded the old fuselage design’s ability to absorb all the forces that are generated as a result. It also changed the handling characteristics of the 737, which then spawned the MCAS system to overcome a tendency to pitch nose up. Hopefully the investigations now under way will throw more light on this and the latest terrifying event.
Boeing was once the watch word for sound design and engineering with a stupendous reputation among aircrews and operators as well as passengers. The change from an on site management philosophy with its roots in the Seattle origins and history of Boeing, to a Chicago based share price, profit driven management style has led many to wonder if this lies behind Boeing’s current woes.
Much of the manufacturing of Boeing aircraft is done by subcontractors and they are now being investigated due to their involvement in the faulty door on the Alaskan 737, which was only twp. months old at the time of the blowout.
A few years ago, Al Jazeera made a documentary entitled, “On a Wing and a Prayer,” about controversies within the minimum price subcontractors who worked for Boeing. It now looks as if that may have been rather prescient.