3 ms·
The new software has been updated to use both sensors. It won't activate when sensors disagree by more than 5.5 degrees. The new software now only does a singl
by phire 7y ago
The new software has been updated to use both sensors. It won't activate when sensors disagree by more than 5.5 degrees.
The new software now only does a single stabilizer movement. They have eliminated all known failure conditions which might cause multiple movements.
With only a single movement, the pilots will be able to counteract the force.
Two sensors is not quite as good as three sensors. It can't know which sensor is bad. But it can disable itself and prevent unintended activations.
The new software, when combined with adequate pilot simulator training to both disable MCAS when it encounters an issue, and to fly the plane in with MCAS disabled makes things safe enough.
- vkou 7y agoSo, this fixes the MCAS problem (Where the plane plunges nose-first into the ground, despite the best attempt by the pilots to pull the stick up)... But how does this fix the problem that MCAS was supposed to be a band-aid over (That the plane is aerodynamically unstable during take-off, and pulling too much on the stick will cause the plane to easily stall)..? The new MCAS sounds like it will only protect against this instability once - and, if overriden, will not do anything to protect against a stall?
- tzs 7y ago> But how does this fix the problem that MCAS was supposed to be a band-aid over (That the plane is aerodynamically unstable during take-off, and pulling too much on the stick will cause the plane to easily stall)..? MCAS is not even enabled during take-off, which makes it hard to see how it could be meant to address supposed stability problems during take-off. It can't come on until the flaps are retracted.
- sokoloff 7y agoThe 737-Max is not “aerodynamically unstable”. (It does not exhibit negative longitudinal stability.)
- phire 7y agoI mean, that's true of every plane. You pull back too much, it will stall. It's not that the MAX stalls super easily, It's not an instability. It's just that the controls feel wrong when approaching stall. The FAA have pretty precise regulations about how much backpressure the pilots should feel when approaching stall. In normal flight, the plane is never anywhere near stalling, so MCAS never activates. Nor do the pilots encounter this weird stall. The combined chances of both MCAS being disabled AND the pilot not recognizing the stall is pretty low. But this is why the simulator training is important, so the pilots are familiar with the new feel as the plane approaches stall.