[jacquesm]

> It's a fundamentally unstable airframe.

The 737 MAX is not a 'fundamentally unstable airframe', though there are points in the flight envelope where it is close to becoming unstable. The definition of an unstable aircraft is when the center of pressure is forward of the center of gravity, a condition which never occurs in the 747 MAX flight envelope, though it comes perilously close to it in some edge cases.

As you correctly identify the engines being 'too big and too far forward' is a factor here, but the most important part of it is the extra lift created by the engine bodies, not the power of the engines themselves.

[CaptainZapp]

Let's just say that Boeing pushed a 50 year old design to places to which it never was supposed to pushed to.

Full blown panic about Airbus' offerings had a lot to do with this faithful decision.

The first crash was a combination of greed, bad design decisions, rush to market and all that in combination with an FAA that was in Boeing's pocket.

The fact that they didn't immediately pulled the plane after the Lion Air crash and the second crash was nothing less than corporate mass murder for profit.

[AlphaSite]

I was under the impression the Max vs a clean room design was actually pushed by airlines, rather than by Boeing it’s self. They wanted a new form scratch design, much like the 787.

Now not to remove responsibility from them, ultimately they buckled under pressure and did the deed.

[kayfox]

That's exactly what happened, Boeing wanted to re-design the 737 with a new type certificate and all that, but the airlines pushed for a re-engined 737.

In the end the 737 MAX is largely a good design, just with one big fuckup.

There's also a certain irony that Boeing would have been able to push out a software update before the Ethiopian crash if the government was not shut down for a month over Dec 2018-Jan 2019.

[kayfox]

They had a software update to correct a bunch of issues with MCAS in the pipe, but it was delayed by the government shutdown.

If there had been no government shutdown, the Ethiopian Airlines crash might not have happened.

[ddalex]

You keep pushing the blame on the government shutdown.

Boeing could itself grounded the airplanes without government intervention but corporate greed won.

Other governments are to blame ibdeed for relying on FAA certification instead of doing their own. I guess that won't happen again.

[kayfox]

> You keep pushing the blame on the government shutdown.

I've actually only mentioned it in two or maybe three comments over the last year.

Your operating from the benefit of hindsight. All the information about the Lion Air crash is out now, you can look at it and decide it should have been grounded. At the time it was not very clear what had happened and why and if it was issues with the pilots or the aircraft or both. Boeing had more information than the public, but not as much as came to light after the Ethiopian Airlines crash.

Also, Boeing does not actually have the authority to ground aircraft they make, they have to push the FAA to do it. The FAA will want to have a good reason, because if the FAA does something that needlessly costs the airline industry lots of money, people at the FAA loose their jobs.

So, its pretty much fuckups all around.

[ddalex]

> decide it should have been grounded

It should haven't been flown in the first place, as it breaks the rule of having a full-authority control system dependent on a single non-redundant sensor.

Boeing got approval for a limited-authority control system, and then modified it to be full-authority without redoing the paperwork. They KNOWINGLY LIED on the type certification documentation. If they wouldn't have lied the aircraft wouldn't have gotten of the ground in the first place.

> Boeing does not actually have the authority to ground aircraft

They do, it's called an Airworthiness Directive and a manufacturer can ask for it and FAA will comply. Even if the FAA is un-operative due to a US government shutdown, they could've notified EASA, CAA, etc. to prevent a knowingly-faulty plane from flying. They CHOSE to cover it.

> the FAA does something that needlessly costs the airline industry lots of money

Try to balance corporate greed vs safety, and it won't end well because lives of people some place far away don't have monetary value to FAA. Safety MUST be paramount in all aspects, trumping profit, because otherwise people will die.

[mechhacker]

Yes, from everything that I've researched about this (not working in this industry anymore), MCAS was to adjust the feel of the controls when at the edge of the flight envelope. The plane, during normal flight, would behave very similarly to existing 737s.

What I read that shocked me was that Boeing was relying on a single angle of attack sensor at a time, with software rules that should have never flown. Such as: not tossing out obviously impossible angle of attack readings, doubling down on nose-down stall corrections, and not limiting MCAS to an input that ensured pilot controllability if the electric trim had to be disabled. (this may not have been possible, actually, in certain flight regimes)

The system pushed the plane into a regime where, from everything I have read, the aerodynamic forces were strong enough that manual pilot trimming (via a physical wheel near the control column) was not possible for a normal human, especially while the pilots were experiencing negative G's from such a strong nose-down trim. The flight log information I could find showed a very difficult cockpit situation. Enabling electric trim (and MCAS) shoved the nose downward, but also allowed some level of trim correction by the pilots that they could not achieve with the trim wheel. Stick forces were also enormous on the elevator, having to pull back over 50lbs if my memory serves.

Imagine yanking back with all your might while fiddling with secondary controls that also required enormous force to move, while the plane is forcing you up and out of your seat, against the seatbelt. This is where any cockpit communication issues between the two pilots would be severely complicating.

That Boeing released this with such flaws, and the FAA accepted it, seems quite damning to Boeing and the FAA. This is something that I can imagine technical leadership and management at Boeing would know about and should have caught and stopped much earlier in the process.