Netspark's Blog

Oct 19 2019

Boeing 737MAX and the bad MCAS

It seems as if there is another back set in Boeing’s history
of the 737MAX which got grounded a year ago after 2 fatal
plane crashes due to their faulty MCAS system (aa assis-
tant to keep the machine out of the stall situation).

MCAS stands for Maneuvering Characteristics Augmentation System and is supposed to
assist the pilots once the machine tends to drift into stalling which inevidently means plane crash.

In the case of the 737MAX, however, it caused two machines to drift into the fatal staling and the pilots were unable to bring the machine back into safe zone. Due this, 338 persons lost their lives when the Lion Air Flight 610 crashed into the Java sea on October 29th, 2018 and the Ethiopean Airlines Flight 302 crashed on ground 6 minutes after takeoff in Addis Abeba.

In both cases it seemed that the MCAS still was interfering with the pilots’ attempts to get the machine back into saf zone away from stalling. In both cases the MCAS pulled the planes’ noses up although the angle would be greater than allowed causing an airflow stop at the wings and put the machine into stalling.

Almost one year later there is another protocol showing that the MCAS even in simulation flights put the pilots into dangerous situations:

An excerpt of the chat history of two pilots discussing the MCAS in training in the simulator:

Mark Forkner 6:50 PM:
Oh shocker alerT!
MCAS is now active down to M .2
It’s running rampant in the sim on me
at least that’s what Vince thinks is happening

Gustavsson, Patrik H 6:51 PM:
Oh great, that means we have to update the speed trim descritption in vol 2

Mark Forkner 6:51 PM:
so I basically lied to the regulators (unknowingly)

Gustavsson, Patrik H 6:51 PM:
it wasnt a lie, no one told us that was the case

Mark Forkner 6:51 PM:
I’m levelling off at like 4000 ft, 230 knots and the plane is trimming itself like craxy
I’m like, WHAT?

Gustavsson, Patrik H 6:52 PM:
that’s what i saw on sim one, but on approach
I think thats wrong

According to the chat it seems as if the pilot tries to push the machine back into safe zone and the MCAS stops him from doing that with all force. It seems as if the simulation ended with a “crash” due to stalling and Mark Forkner admitted that he commted wrong statements to the FAA.

The full chat history is available as PDF:

Boeing Document

Or at it’s origin (Reuters) here:
https://graphics.reuters.com/BOEING-737/0100B2J51TY/Boeing%20Document.pdf

Due to this fact, the FAA was not very amused and released a statement:

Late yesterday, Boeing alerted the Department of Transportation to the existence of instant messages between two Boeing employees, characterizing certain communications with the FAA during the original certification of the 737 MAX in 2016. Boeing explained to the Department that it had discovered this document some months ago.

The Department immediately brought this document to the attention of both FAA leadership and the Department’s Inspector General.

The FAA finds the substance of the document concerning. The FAA is also disappointed that Boeing did not bring this document to our attention immediately upon its discovery. The FAA is reviewing this information to determine what action is appropriate.

The FAA has shared this document with the appropriate Congressional committees and plans to provide additional related documents today.

The FAA is following a thorough process, not a prescribed timeline, for returning the Boeing 737 MAX to passenger service. The agency will lift the grounding order only after we have determined the aircraft is safe.

There’s also an official letter from the FAA sent to Boeing’s CEO:

FAA_Boeing_letter

The letter can be read at it’s origin here:
https://www.faa.gov/news/media/attachments/Boeing_letter.pdf

alongside with the online statement cited above:
https://www.faa.gov/news/updates/?newsId=93206

This is indeed no good statement for Boeing and the early re-engagement of the 737MAX as safety is still not guranteed. It is said that the 737MAX will be grounded till H1 2020 and most flight companies have already cancelled flights that were supposed to be done with the 737MAX.

October 19, 2019 Netspark - 1599 posts - Member since: May 9th, 2011 No Comments »

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