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The alternative would have been redesigning the 737 such that it would be a different plane. There are advantages to keeping it as similar as possible to the pr
by js2 8y ago
The alternative would have been redesigning the 737 such that it would be a different plane. There are advantages to keeping it as similar as possible to the previous generation. Boeing was in a bit of a bind. They had a plane (the 737) originally designed for different requirements (the plane is low to the ground) in wide spread use that the airlines wanted them to make more fuel efficient to stay competitive with Airbus’s latest models. If they introduced a new plane that would require the airlines to retrain all their 737 pilots among other things. So Boeing found a way to put new engines on while keeping the plane similar enough as not to make it a new type.
From what I understand, MCAS is a reasonable solution. Where it gets questionable is in not informing the pilots of this new system (but again, there were reasons for that, maybe as it turns out not good reasons), allowing the new system to override the yoke input (Boeing reasoned there was already a procedure for runaway trim pilots would follow), and keying the new system off a single AoA sensor and only having two AoA sensors total so it’s not clear what to do when they disagree.
- michaelt 8y agoI'm not clear on why having different engines, different handling and MCAS makes it not-a-new-plane, but having the landing gear extend further down would make it a new plane?
- deleted 8y ago[deleted]
- mannykannot 8y agoI don't think it is a binary 'either its a new plane or its not' situation. I think every change has to be scrutinized for its safety implications, and for MCAS the analysis seems to have been, in part, that a failure could cause a trim runaway, but trim runaway is a circumstance for which there already exists a response, and that would not need changing (what this overlooked was that the pilots would experience it differently, as pulling back will not stop it, and if they stopped it with the trim button but didn't disable it, it would start up again ten seconds later.) Putting a longer undercarriage on an airplane is not a trivial matter. You have to design it, test it, get it certified (a new undercarriage raises obvious safety issues) and put it into production. It's not just the undercarriage - it won't fit into the existing wheel wells, and furthermore, the legs might have to be moved further out on the wing, and then you have to rework that, as well.