Ethiopian airlines pilots initially followed Boeing’s emergency steps to disable 737 MAX system

Pilots at the controls of the Boeing Co. 737 MAX that crashed in March in Ethiopia initially followed emergency procedures laid out by the plane maker but still failed to recover control of the jet, according to people briefed on the probe’s preliminary findings.

After turning off a flight-control system that was automatically pushing down the plane’s nose shortly after takeoff March 10, these people said, the crew couldn’t get the aircraft to climb and ended up turning it back on and relying on other steps before the final plunge killed all 157 people on board.

The sequence of events, still subject to further evaluation by investigators, calls into question assertions by Boeing BA, -1.56% and the U.S. Federal Aviation Administration over the past five months that by simply following established procedures to turn off the suspect stall-prevention feature, called MCAS, pilots could overcome a misfire of the system and avoid ending in a crash.

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.

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