Thread: Ethiopian air lines flight goes down all killed

from the link you posted

The automated system, known as MCAS, activates if just one of two sensors mounted on the aircraft’s exterior says the nose is too high

usually these things have 3 sensors and 2 of the 3 have to agree before action is taken (so that 1 faulty sensor wont cause a problem)

Two of my relatives flew Ethiopian Air over the weekend and lived to tell the tale.

Originally Posted by DiscoMick

Two of my relatives flew Ethiopian Air over the weekend and lived to tell the tale.

Bet they were not in a MAX8

No, they are grounded.
You have to feel for reputable airlines which buy planes like the Boeing assuming they are getting the best for their passengers, and then this happens.
I bet Airbus gets some sales out of this.

Originally Posted by Eevo

from the link you posted




usually these things have 3 sensors and 2 of the 3 have to agree before action is taken (so that 1 faulty sensor wont cause a problem)

The B737 has 3 pitot tubes, 2 alpha vanes, and 1 TAT probe.

L alpha vane goes to FCC 1
R alpha vane goes to FCC 2

Only one FCC provides input for the MCAS at any given time. It alternates every flight when the aircraft remains powered. Therefore only one alpha vane is providing data at any one time to the MCAS, therefore no ‘agreement’.

The 3 pitots are totally independent and separate, and also do not require any ‘agreement’ value for any part of the system to function. There is a message for ‘IAS Disagree’ to advise that there is a difference between the captain’s and FO’s airspeed indicators (once again, no effect on other systems), but it does refer you to the Airspeed Unreliable checklist to deal with the problem to troubleshoot the faulty indicator, The third pitot (standby) has no comparator.

Originally Posted by Hugh Jars

The B737 has 3 pitot tubes, 2 alpha vanes, and 1 TAT probe.

L alpha vane goes to FCC 1
R alpha vane goes to FCC 2

Only one FCC provides input for the MCAS at any given time. It alternates every flight when the aircraft remains powered. Therefore only one alpha vane is providing data at any one time to the MCAS, therefore no ‘agreement’.

yep, and it looks like that design has failed.

A faulty sensor , apparently.

Boeing Plans to Fix the 737 MAX Jet With a Software Update | WIRED

" black " boxes, how they get the data. Interesting, to a layman like me.


How Investigators Pull Data off a Boeing 737’s Black Boxes | WIRED