[Zathras]

EETimes assessment of the problems with 737 Max.
Written by engineers, for engineers.
They feel it is a airframe design flaw caused by moving new engines forward.

https://www.eetimes.com/document.asp?doc_id=1334482

[Moonman62]

I’d rather go with the opinion of a 737 pilot.

https://www.youtube.com/channel/UCwpHKudUkP5tNgmMdexB3ow

[cuban leaf]

I had heard something about this. The idea is that you should be able to basically balance an airplane (front to back) at a point on the fuselage around the center of the main wings. If they moved that point farther forward, it almost suggests the plane needed the addition of a canard wing to compensate.

Trying to save money to avoid all the testing, etc. by making it a different airplane, they may have pushed the “modifications to an existing airframe” envelope too far on this one.

[WhoisAlanGreenspan?]

Excellent article, thanks for the Link to eetimes

And here's the referenced article by Gregory Travis; This is aerodynamic malpractice of the worst kind.

[ProtectOurFreedom]

This has been documented extensively since the Lion Air crash. Greater fuel economy required the much larger next-generation LEAP engine with high air bypass ratios. This makes the engine larger in diameter and it wouldn't fit under the wing. To make it fit, Boeing made the landing gear taller and moved the engine forward so the nacelle could clear the leading edge of the wing.

This changed the handling characteristics of the aircraft. Worse, the nacelles generate their own lift at high angles of attack. With the engines farther forward of the aircraft center of gravity, the engines generate an upward pitching moment. To make matters worse, it's a positive feedback system -- the higher the angle of attack, the more lift the nacelles generate pitching the aircraft higher which generates more lift on the nacelles, etc. I've read this positive feedback pitch-up can happen very quickly, hence the need for automation (i.e., MCAS) to counter the effect very quickly.

A reader comment on the EE Times article links to an interesting analysis by Gregory Travis at Boeing 7373MAX. Mr. Travis confirms what I've read, but adds an interesting financial analysis. He says these handling changes should have required this to be classified as an entirely new airframe requiring complete FAA certification, a process that would take years and costs untold millions of dollars. He says that Boeing created the fiction that the MAX would have the flight characteristics of other 737 types and not require complete new certification or pilot retraining.

He writes that FINANCIAL considerations beat out SAFETY considerations on the MAX.

In my opinion, all of this can be laid at the feet of the extreme environmental lobby over the past decades. They have forced governments to adopt fuel economy standards and emission standards for cars, trucks, planes, ships...any transportation system. It was inevitable that the endless quest for higher fuel economy was going to reach diminishing returns and probably result in lives lost.

The automobile analog is the continued weight reduction of cars which led to more severe, more deadly crashes and higher loss of life.