737 Max

[JLv3.0]

MCAS existed within the flight control systems on the previous gen B737, and has existed on Airbus forever

Ian - just give us some words on that, can you, before this gets all emotional

[NotoriousREV]

If the worst thing anyone can say about me is that I’m well read, knowledgable and critical, I’ll take it

[NotoriousREV]

MCAS existed within the flight control systems on the previous gen B737, and has existed on Airbus forever

Ian - just give us some words on that, can you, before this gets all emotional

It’s definitely been part of the Airbus forever. It’s the assertion it was on the 737NG I think he’s wrong on, at least in the form it’s in on the MAX. And I’m basing that on what Boeing has said publicly.

[JLv3.0]

Gotcha. I was wondering if it was implemented under a different name previously or summat.

[NotoriousREV]

I’m not questioning anything else he said

[IanF]

Lol! It was called something else on the NG - MSR: min speed reversion protection aka high alpha low speed protection. Bascically, when you get near stall speed (1.3x speed in current config) the aircraft will mode change so it can pitch down and maintain its speed. It’s not just the NG that had this either.

Honestly, believing everything Boeing says on its sales pitch!

Next you’ll be saying all Volvos will be electric by 2020.

[Mito Man]

Fuck I need more popcorn.

[NotoriousREV]

Honestly, believing everything Boeing says on its sales pitch!

Nothing to do with the sales pitch, it's what they said during the investigation into the Lion Air crash. The whole point is that they *didn't* include it in the sales pitch, hence pilots not being aware of its operation or existence. Come on, you should be better than this.

[Rich B]

[NotoriousREV]

Differences between MCP (737NG) and MCAS (737MAX):

- MCP is only there to prevent speed dropping below Minimum speed x 1.3 for a given flap configuration - MCAS is there to prevent stall during tight turns at high AoA induced by the larger engines, altered centre of gravity and aerodynamics of the nacelle design.
- MCP only operates in AP mode - MCAS operates in all modes
- MCP can pitch nose up or down whilst increasing thrust to N1 to maintain speed - MCAS only pitches nose down
- MCP can be overridden by exiting AP - MCAS needs to be powered off via 2 breaker switches and then overridden manually by the pilot

Other than that, they're identical

[IanF]

Differences between MCP (737NG) and MCAS (737MAX):

- MCP is only there to prevent speed dropping below Minimum speed x 1.3 for a given flap configuration - MCAS is there to prevent stall during tight turns at high AoA induced by the larger engines, altered centre of gravity and aerodynamics of the nacelle design.
- MCP only operates in AP mode - MCAS operates in all modes
- MCP can pitch nose up or down whilst increasing thrust to N1 to maintain speed - MCAS only pitches nose down
- MCP can be overridden by exiting AP - MCAS needs to be powered off via 2 breaker switches and then overridden manually by the pilot

Other than that, they're identical

MCP - mode control panel?

[IanF]

You do realise you’re just talking about autopilot functions!?

[NotoriousREV]

You do realise you’re just talking about autopilot functions!?

MCAS operates independently from AP.

Boeing, FAA, CAA, EASA, Pilot's Unions, 737NG and 737 MAX pilots, and engineers are all saying it's a new feature on the 737MAX. With respect, Ian, I'm going to listen to them and not you on this one.

[Maurice]

I’m really not sure who I should be aiming “aviatiown3d” at yet.

Can someone let me know when things pan out a bit more clearly?

[IanF]

I’ve not read anything that links the Regulating Authorities or Unions to MCAS other than them both being in the same news articles. Have you seen a statement where Boeing , Unions or Authorities state anything about MCAS?

[NotoriousREV]

I assume you mean other than the FAA ordering Boeing to make changes to the MCAS software following the Lion Air crash?

[NotoriousREV]

https://www.faa.gov/news/updates/media/CAN_2019_03.pdf

[NotoriousREV]

This is the data from the Lion Air crash. Note Autopilot is not engaged and that every time manual trim is set, auto trim does the opposite:

[Simon]

We've definitely nearly reached agreement on this.

[NotoriousREV]

https://www.seattletimes.com/business/b ... air-crash/