3 ms·

> AND make a second sensor an optional extra cost for the airlines This would be extremely egregious, but it's not what happened. Every MAX has two AoA vanes.

> AND make a second sensor an optional extra cost for the airlines This would be extremely egregious, but it's not what happened. Every MAX has two AoA vanes. Every MAX only hooks up the MCAS to one vane. The optional feature was just an "AOA disagree" light and display, which wasn't even hooked up to an error alarm. It's a red herring for these crashes, in my opinion. The pilots aren't going to hunt around the cockpit during an emergency and notice a disagree light and be able to conclude anything meaningful about what's happening to the plane and how to stop it.

alvah 8y ago
They could have had "check for AoA disagree" as part of the pre-flight checklist though - I read somewhere that in at least 1 of the MAX crashes, the AoA vanes disagreed on the ground before departure.
- tlb 8y ago
  Are they expected to agree when there's no airflow? What direction should they be pointing in?
  - cjbprime 8y ago
    You're right, they're literally vanes on the side of the aircraft, they don't do anything without airflow. Takeoff roll is when you could possibly first notice it.