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Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards

wsj.com

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Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards

#2
Here is some non pay-walled content: https://qz.com/1718506/boeings-737-max-mcas-has-better-desig...

The key quote from there:

Notably, pilots of the KC-46 are able to override the MCAS—or Maneuvering Characteristics Augmentation System—simply by pulling on the controls, the Journal reports. It quotes an Air Force procurement chief as saying, “We have better sensor data. But most importantly, when the pilot grabs the stick, the pilot is completely in control.”

Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards

#3

Here is some non pay-walled content: https://qz.com/1718506/boeings-737-max-mcas-has-better-desig... The key quote from there: Notably, pilots of the KC-46 are able to override the MCAS—or Maneuvering Characteristics Augmentation System—simply by pulling on the controls, the Journal reports. It quotes an Air Force procurement chief as saying, “We have better sensor data. But most importantly, when the pilot grabs the…

It's weird to see an article writing about this without mentioning the regulatory and training aspect. Previous MAX MCAS *couldn't" allow the pilot to override with the stick, because previous MCAS both needed to prevent a pilot-induced stall and needed to require no training or knowledge from the pilot in order to maintain the type rating.

A better way to write the article would be "Boeing and the airlines have given up on trying to do MCAS without telling pilots anything about it."

Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards

#4
post #3

Here is some non pay-walled content: https://qz.com/1718506/boeings-737-max-mcas-has-better-desig... The key quote from there: Notably, pilots of the KC-46 are able to override the MCAS—or Maneuvering Characteristics Augmentation System—simply by pulling on the controls, the Journal reports. It quotes an Air Force procurement chief as saying, “We have better sensor data. But most importantly, when the pilot grabs the…

It's weird to see an article writing about this without mentioning the regulatory and training aspect. Previous MAX MCAS *couldn't" allow the pilot to override with the stick, because previous MCAS both needed to prevent a pilot-induced stall and needed to require no training or knowledge from the pilot in order to maintain the type rating. A better way to write the article would be "Boeing and the airlines have give…

> previous MCAS both needed to prevent a pilot-induced stall

MCAS is there mostly because of certification requirements for hands-off stability. It is not a mechanism to prevent the pilot from stalling the aircraft.

Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards

#7

Moderators: please add [paywalled] or [$] to paywalled content so I can ignore instead of wasting time. Thanks.

https://news.ycombinator.com/newsfaq.html

> But please don't post complaints about paywalls. Those are off topic.

Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards

#9
post #4
post #3

Earlier quoted context omitted.

It's weird to see an article writing about this without mentioning the regulatory and training aspect. Previous MAX MCAS *couldn't" allow the pilot to override with the stick, because previous MCAS both needed to prevent a pilot-induced stall and needed to require no training or knowledge from the pilot in order to maintain the type rating. A better way to write the article would be "Boeing and the airlines have give…

> previous MCAS both needed to prevent a pilot-induced stall MCAS is there mostly because of certification requirements for hands-off stability. It is not a mechanism to prevent the pilot from stalling the aircraft.

I don't agree. I think the lift from the nacelles results in decreasing stick backpressure while the nose is being raised in some circumstances, which is both a handling issue and an airworthiness violation. It's an airworthiness violation because it exacerbates rather than discourages stalls. If the pilot continues pulling back on the stick with reduced backpressure the plane would stall, therefore MCAS is (indirectly) an anti-stall device.

It's hard to know what the real issue is, because Boeing isn't forthcoming about it. But your claim that the airframe is fundamentally aerodynamically unstable ("needed for hands-off stability") is a very extreme claim that I don't think is supported.

Re: Before 737 Max, Boeing’s Flight-Control System Included Key Safeguards

#10
post #8

But presumably the pilots of both downed MAXs were pulling back as hard as possible.

>Suneja hauled his control column all the way back, giving full up elevator to no avail. The nose dropped farther as the stabilizer prevailed. The crew of an offshore oil platform saw the airplane in a nearly vertical dive before it hit the water.(Lion Air Flight 610)

>As the speed shot through 450 knots, the pilots hauled back on their control columns to no effect. Six minutes after takeoff, the airplane hit the ground doing approximately 600 miles an hour. It buried itself into a 30-foot-deep crater in farmland about 32 miles southeast of the airport. Within a week, the Boeing 737 Max was grounded worldwide. (Ethiopian Airlines Flight 302) From: https://www.nytimes.com/2019/09/18/magazine/boeing-737-max-c...

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