Did Boeing screw up the 737 Max? (SkyRoll Luggage Blog)

What went wrong with the Boeing 737 MAX and did the FAA certify an unsafe airplane? This will become an engineering and business school case study of costly mistakes.

What caused the 737 Max to crash, twice? That is the question everyone wants answered. Technical details are closely guarded by Boeing and the authorities investigating both crashes, but from what’s been revealed so far there appears to be a clear pattern pointing to a series of poor business and engineering decisions, as well as poor government oversight that certified the plane, so there may be a lot of blame to go around.

Let’s start with the 737, a model first introduced in the 1960’s. It is much cheaper to update an existing design than to create a new airplane from scratch, and Boeing has updated the 737 many times, maybe one time too many. The 737 was designed in the era of turbojet engines which were much skinnier than today’s turbofan engines. They were also much noisier and much less fuel efficient, which is why all modern planes use turbofans. But the original 737 also had very short landing gear which makes it harder to keep increasing the size of the engines and still have enough ground clearance. The new LEAP engines on the 737 MAX are the largest yet put on a 737, but they were too large for the height of the landing gear. Redesigning the landing gear was not an option because it would have basically meant building a whole new plane, too expensive and time consuming, and Boeing wanted to save money which lead to business mistake #1: being too concerned about cost.

This meant mounting the engines higher and further forward on the wings which created an aerodynamic problem and changed the way the plane handled in certain conditions. It created a tendency for the plane to pitch up and possibly stall, which is the last thing you want to happen, so the engineers do what all engineers do, they created a workaround solution. In this case the solution was software called MCAS that would force the nose of the plane down if it thought it was about to stall. There were multiple problems with this solution, let’s call it engineering mistake #1. The software relied on input from just one sensor, even though there were two sensors on the plane, meaning a faulty sensor would confuse the software even if the other non-faulty sensor gave it accurate information. But it gets worse, because Boeing made the decision to not inform airlines or pilots about this software “solution”. Why? Because they were trying to save the airlines money on having to retrain their pilots, business mistake #2. And the airlines are somewhat at fault here because they loved the idea of saving money on pilot training.

The software “fix” that the pilots were unaware of had its own set of problems but without knowing the exact instructions it was carrying out it’s hard to be sure just how faulty the fix was. What is clear is that even when the pilots tried to counteract the faulty instructions to point the nose down, the software would not let them fly the plane manually to do so. In other words, the software assumed it was right and the pilots were wrong and would not let them do “the wrong thing”. While there are plenty of examples where this kind of automation works well and really does keep pilots from doing the wrong thing and endangering the plane, this clearly was not one of them. So lets call the way the software was designed engineering mistake #2.

Now it’s time to point a finger at the FAA, whose job it was to certify the plane safe to fly. The FAA, due to a long list of budget and technical expertise constraints, pretty much let Boeing certify the plane. It’s not clear from any of the reports made public if or how Boeing or the FAA even tested the MCAS system and its reliance on a single sensor. Oversight mistake #1. It has also been made public that pilots from several airlines in the USA have been complaining about the MCAS system to both Boeing and the FAA since well before both crashes asking for a software update to make the system safer and the plane easier to control, but there seemed to be no urgency on the part of Boeing or the FAA to require an update. Let’s call this business mistake #3, engineering mistake #3 and oversight mistake #2.

After the second 737 Max crash country after country ordered the plane grounded until the problem was understood and fixed, yet both Boeing and the FAA dragged their feet. What were they thinking? This made both Boeing and the FAA look very bad and will probably hurt the reputation of both for years to come: business mistake #4, engineering mistake #4 and oversight mistake #3. The bottom line is that Boeing’s plan to save themselves and their customers time and money will cost everyone a lot of both. It means that almost 400 people died needlessly. It means that Boeing’s hard-earned reputation is in tatters and they will probably lose orders for the 737 Max and will face a wave of lawsuits. Maybe Boeing should have just designed a new plane in the first place. I’m sure they are having meetings about this as we speak.