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Wed Mar 13, 2019, 11:00 AM

After a Lion Air 737 Max Crashed in October, Questions About the Plane Arose

Feb. 3, 2019

In the brutally competitive jetliner business, the announcement in late 2010 that Airbus would introduce a more fuel-efficient version of its best-selling A320 amounted to a frontal assault on its archrival Boeing’s workhorse 737.

Boeing scrambled to counterpunch. Within months, it came up with a plan for an upgrade of its own, the 737 Max, featuring engines that would yield similar fuel savings. And in the years that followed, Boeing pushed not just to design and build the new plane, but to persuade its airline customers and, crucially, the Federal Aviation Administration, that the new model would fly safely and handle enough like the existing model that 737 pilots would not have to undergo costly retraining.

Boeing’s strategy set off a cascading series of engineering, business and regulatory decisions that years later would leave the company facing difficult questions about the crash in October of a Lion Air 737 Max off Indonesia.

https://www.nytimes.com/2019/02/03/world/asia/lion-air-plane-crash-pilots.html

Long and excellent article published BEFORE the Ethiopian Airlines crash. Note that this was based on the preliminary Lion Air crash report and on investigative reporting.

As far as I can tell, the final report on the Lion Air crash has not yet been released.

It seems likely that the flight simulators used for pilot training by most airlines have not been updated to include MCAS malfunctions in their training scenarios. From interviews with pilots on news shows, it appears that the training for US airlines has been modified for these scenarios, including cockpit displays added in the US.

More from the article:

In designing the 737 Max, Boeing decided to feed M.C.A.S. with data from only one of the two angle of attack sensors at a time, depending on which of two, redundant flight control computers — one on the captain’s side, one on the first officer’s side — happened to be active on that flight.

That decision kept the system simpler, but also left it vulnerable to a single malfunctioning sensor, or data improperly transferred from it — as appeared to occur on the day of the crash.

There is no evidence that Boeing did flight-testing of M.C.A.S. with erroneous sensor data, and it is not clear whether the F.A.A. did so. European regulators flight-tested the new version of the plane with normal sensor data feeding into M.C.A.S. but not with bad data, the pilot familiar with the European certification process said.

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Reply After a Lion Air 737 Max Crashed in October, Questions About the Plane Arose (Original post)
Troll2 Mar 13 OP
def_con5 Mar 13 #1
DDKick Mar 13 #2
Hey Mikey Mar 13 #3
Troll2 Mar 13 #4

Response to Troll2 (Original post)

Wed Mar 13, 2019, 11:42 AM

1. Can we at least wait

till a preliminary investigation has an initial finding.There are eye-witness reports the aircraft was on fire prior to the crash.

You can hang Boeing after we have a feel for what happened.

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Response to def_con5 (Reply #1)

Wed Mar 13, 2019, 11:45 AM

2. None of it matters really. Democrats plan to get rid of planes

AOC said , what was it 10 years or 12?

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Response to Troll2 (Original post)

Wed Mar 13, 2019, 08:58 PM

3. These are both 3rd world nations, also

Lots of MAXs flying in the U.S. Shouldnt an aircraft worthiness issue arise by now in the US?

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Response to Hey Mikey (Reply #3)

Wed Mar 13, 2019, 10:33 PM

4. The pilots union in the US has insisted on training, and at least SW has additional cockpit displays

The three US operators also have a fairly large number of MAX each. So they've taken extra steps to inform their pilots.

That's at odds with Boeing's strategy which is to claim that no added training is needed on the MCAS system. That allows Boeing to sell a handful of planes each to a couple dozen smaller airlines globally. Were training required, they would have trouble with their marketing plan.

Boeing probably needs to have redundant angle-of-attack sensors, have an angle-of-attack display (like SW's), and better defensive programming in the case of bad or inconsistent sensor inputs. It should also be easier to disconnect the system and restore stabilizer trim. Currently the latter has to be done using manual wheels.

And all this needs to be rehearsed in appropriately modified simulators.

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