OK, I finally got some time with my laptop to actually type this out. Also, I can’t get line breaks to work so I’m splitting paragraphs with hard lines for readability.
The bottom line is that most info on the 737 Max is from news sources that make money off of controversy or parties with an agenda.
Re-engining existing designs is not new and this isn’t unique to the 737-Max. The 737-100 was an old school low bypass engine that was much smaller in diameter than modern high bypass engines. When they wanted to go with more modern engines with the 737-300 they ran into the issue of the wing being too low for the wider engines and they moved it in front of the wing and up to get required ground clearance, this is also what gave the 737 the signature lopsided engine look since they put all the accessories on the sides to maximize ground clearance. For the 737-Max they were fitting even larger engines than before so they use the tried and true “move it forward and lift it technique” that had worked for decades. This did affect center of gravity and thrust (and also lift, Mean Aerodynamic Chord or MAC is equally if not more important here) and as a result introduced some pitch tendencies to power changes.
Handling characteristics are nothing to to planes, airliners, Boeing or the 737; they’re a fact of life. Wanting similar planes to handle similarly isn’t “gaming the system” or cheating, it is a desirable outcome. With fly by wire systems, handling characteristics are tunable, the same as any modern car with stability control. Teaching the system to overcome the difference in center of thrust vs MAC isn’t scandalous or evil, it’s just basic aircraft design in modern times. Also, when the FAA asks how it handles, telling them “we added software fixes to the flight controls that make it mirror previous generations, independent test pilots all agree it is comparable” is a valid answer.
Now I will break and say this is where I do disagree with some of the choices Boeing made. I am not a Boeing fanboy and despite flying a Boeing (albeit one that became a “Boeing” when they bought McDonnell Douglas). I think their shift from having engineers in charge at the executive level to bean counters from GE/3M they made decisions that have degraded the quality of their product. This doesn’t mean they aren’t safe and functional aircraft, it’s like when I bitch about Subaru putting the oil filter inside the “ring of fire” circle of hot exhaust manifold or placing the fuel filter inside the fuel tank. My main issue with the 737-Max and MCAS is the way the fly by wire corrected for the handling by using pitch trim, but I’ll explain that next.
As I said Boeing didn’t lie or hide anything, they simply did the minimum required and the FAA didn’t ask for any more when given a simple answer. The plane passed all tests and, per all the test pilots, flew the way they said it would. The issue is what happened if anything went wrong with the way that they made it fly the way they said it would. For any large aircraft, pitch trim is a big deal. Leaving the elevator deflected at cruise creates tremendous drag so instead the entire rear stabilizer moves. This is far more aerodynamic but creates a danger because the moving surface is so large that if it does go outside of the normal range, the plane becomes unflyable. Because of this, every single pilot of large planes is taught to be aware of unintended stabilizer motion. Now going back to what I was saying before, the way MCAS worked is that it was basic computer code saying “if power makes nose go up, move tail until nose goes down.” It works and all, but inducing continuous stabilizer motion just seems sloppy to me as both a pilot and a computer science degree holder. I am not an aerospace engineer though, so I’m guessing there is more to it such as elevator not having enough authority to counter it the way the stabilizer does and odds are there is a reason they picked this, I just don’t personally like it because as a pilot “stabilizer motion” scares me more than “stall, stall, stall” when the jet yells at me.
This brings me to my final point and back to what I was originally saying. Even if MCAS was a subjectively sloppy execution of a system, it should not have ever led to a fatal mishap. If a car company has a system that under very rare, unknown and specific circumstances can deflate a tire over the course of 20 highway miles or so, is it their problem for not predicting this and informing the NTSB prior to selling it to the public despite meeting all requirements and passing all tests for certification? While yes, it’s an issue and yes, the cars can be made safer once it is known, if you have 15 miles to pull over after your TPMS light comes on would you expect someone that is unaware of this car feature/flaw to keep driving for another 10 minutes, with the TPMS light on, without ever pulling over and checking their tires? That is what happened in both 737-Max crashes. No, pilots were not given specific training on MCAS, but they were absolutely trained on what to do for stabilizer motion. The fact that they had uncommanded stabilizer motion and never ran the appropriate checklists is absurdly damning of them. A huge part of pilot training for type ratings is learning how to triage situations and pick the correct checklist to run; “stabilizer motion” is virtually always the first one. Seriously, if I have an engine on fire and stabilizer motion, I’m disabling the trim before I shut down the engine, it can burn clean off the pylon for all I care, the plane can fly just fine on the remaining engines. It’s also worth saying that during mishap investigation training “blaming the pilots” is the easiest answer that is discouraged in virtually all situations. It’s never “he flipped the wrong switch” but “his training made him mistake this switch for another” or something else. Human error is the easiest scapegoat in any mishap while human factors is what can actually be changed to prevent the next one. Mishap investigation is about prevention, not blame. This is why the second crash is unforgivable. The first crew were in a bad situation beyond their skills and paid the ultimate price for it. The second crew had every resource not just available, but shoved down their throats by the entire world for weeks and still didn’t bother to even brush up on the checklist for a runaway stabilizer. Sometimes, human error is beyond human factors and this is the epitome of it.
All that aside, once there was blood in the water the sharks were sure to circle and that is how the documentaries, exposés and hit pieces on Boeing progressed on the natural cycle. There is always more to the story, but sometimes the full answer is closer to the simple answer than the long answer.