The crash of Lion Air 610 in late October was a tragic mishap that from the beginning had the hallmarks of an accident that never should have happened. Almost immediately suspicions focused on a new system, Maneuvering Characteristics Augmentation System (MCAS), which Boeing introduced to give the new model flying manners the FAA would approve. The changes that MCAS brought to the model were necessitated by Boeing’s use of a new, larger, more powerful and more fuel-efficient engine, the CFM LEAP-1 engines,
The pace at which the 737 Max came to market was very fast compared to most other major programs. The first flight of the plane was just over two years after the configuration was finalized, and the first delivery was made in just 13 months after first flight, time periods far shorter than what is needed typically even for a derivative model, like the Max. It’s no secret why Boeing got moving on its new plane. Airbus’s A320neo was a hot commodity, promising fuel savings and bigger profits for airlines who bought it. Many did. By the end of 2015 Airbus had more than 3,000 orders for the fuel saving single-aisle airliner. Boeing needed to catch up fast or risk losing the segment that it had long dominated with the 737 to its arch-rival.
There were problems, though. The 737 is set very low to the ground, something the company did when it designed the plane in the 1960s in order to accommodate boarding from rolling sets of stairs directly from the ramp, which was common at the time. Its wing-mounted engines, therefore had very slim ground clearance. The larger engine inlet for the LEAP-1 turbofan would necessitate changes to retain sufficient margins. Boeing used a longer nose gear, moved the engines forward and created a more compact engine housing and attachment structure.
With big changes like this in structure, weight distribution and thrust dynamics, the flight characteristics of the plane were certain to change, as well. And they did. So in order to give the plane better margins against a stall, Boeing introduced MCAS. Some commenters have pointed out that MCAS is simply a method for modifying flight feel characteristics of a plane, which is no different from the many electronic and mechanical methods airplane designers have been using for years. It’s true while underselling the issues with MCAS.
Problem One: MCAS Issues
Boeing’s certification of the new system was not only quick, but interviews with engineers involved with the certification of the system paint a picture of a process that was haphazard. MCAS uses mechanical means to adjust the plane’s horizontally configured tail (like a smaller wing at the tail) in order to push the nose down aerodynamically. The rate at which is does this wound up being much faster than originally anticipated, and it would also do so repeatedly, even after the pilots tried to overpower the system in order to bring the nose back up. In essence the system was fighting the human pilots’ efforts to bring the nose back up by pushing it back down farther and farther until the condition is unrecoverable. Should such a design have ever been approved?
Problem Two: Lack of Training Materials
Some in the online community have been quick to point fingers at the pilots of the doomed planes (and by extension the airliners that trained them) for not being able to turn off MCAS. But early on after the Lion Air tragedy it became clear that Boeing had not made any special accommodations to train pilots in how to disable the new system. Shockingly, the existence of the potentially deadly safety system wasn’t noted in training materials. It’s true that just about any safety system if misunderstood can lead to disaster, but Boeing’s introduction of the 737 Max seems to misunderstand or ignore the risk.
Problem Three: Designated Approval Authority
The certification process, as described above went fast, but many of the approvals from the “FAA” were granted by Boeing employees given permission by the FAA to act in its stead.
Problem Four: FBI and Other Investigations
Investigators from the FBI and the U.S. DoT Inspector Generals Office are probing the process to see if Boeing took shortcuts or used undue influence to get approvals for the 737 Max and launch the plane for service before the issues had been worked out in testing. The FBI’s probe could have criminal implications for the company. Investigators are, likewise, probing the FAA’s certification oversight of the plane to see if it failed to live up to its responsibilities to the public.
Problem Five: Lost Confidence, Lost Revenue
5 The New York Times has reported that Lion Air wants to cancel its order for nearly fifty planes valued at nearly $5 billion. The cancellation, the Times story said, was requested because, Lion Air said, its customers had lost confidence in the plane. With more than 5,000 orders, the 737 Max is Boeing’s hottest airplane by far. Losing a sizable chunk of that business could have huge and lasting impacts on the company and on the US economy.
There are, of course, other problems Boeing faces in the wake of the twin 737 Max disasters, including, as we pointed out in this story, a loss of reputation among airlines that buy the planes that Boeing and its competitors make and the pilots who fly them.