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#1 requires fitting another AOA sensor vane. This is not being done. It would void the existing type certification, at which point the reason to avoid a clean-s
by SAI_Peregrinus 6y ago
#1 requires fitting another AOA sensor vane. This is not being done. It would void the existing type certification, at which point the reason to avoid a clean-sheet redesign is gone. If they could have designed a new aircraft around the more efficient engines at the same size and have airlines buy it they would have. But without a 737 type certificate Southwest (their largest single customer for 737s, Southwest only flys 737s) won't buy and many others will be more reluctant to buy.
#2 is being changed.
- hn_throwaway_99 6y ago> #1 requires fitting another AOA sensor vane This is baloney. There are already 2 AOA sensors on the plane, but MCAS originally only read from one of them: https://arstechnica.com/information-technology/2019/03/boeing-sold-safety-feature-that-could-have-prevented-737-max-crashes-as-an-option/ https://arstechnica.com/information-technology/2019/03/boein...
- SAI_Peregrinus 6y agoThere need to be at least 3. With two a disagreement cannot be resolved by majority, so the new MCAS will have to disable itself. Pilots will need to be trained to handle this failure mode, and the indicators will need to be added to all the planes (and will need to work, that was an additional issue). This is a fundamental design flaw for a system which can have catastrophic consequences. This should have been classified as a DO-178B level A system (capable of crashing the plane) but was misclassified by Boeing. DO-178B level A systems require triple redundancy.