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"MCAS is frequently confused with a flight augmentation system which isn’t true. This is demonstrably false. MCAS is a system in the same vein as the MD-11's LS

"MCAS is frequently confused with a flight augmentation system which isn’t true. This is demonstrably false. MCAS is a system in the same vein as the MD-11's LSAS. In other words, a hack to ensure the the "piloting experience" of the MAX stays as similar as possible to that of the 737 NG, despite the fact the NG doesn't suffer from directional pitch instability at high AoA." - This is false because MCAS only activates during stall conditions and is the exact reason why this issue went undiscovered for so long. If it was the system that you say it is, then it would have been constantly making the 2.5-degree adjustments to the horizontal stabilizer all the time! The fact is that it requires an AoA sensor to report an attack angle greater than 25 degrees while airspeed drops below 200 knots. That Aircurrent article was the worst thing for Boeing because it made so many people misinformed. It somehow convinced people that the engine thrust is misaligned making it into some sort of harrier-jet hybrid that's "unstable". Completely false. Look at how many different engines and engine placements have been used throughout the history of flight that didn't require any augmentation system and then tell me that argument still has validity.

salawat 7y ago
>This is false because MCAS only activates during stall conditions and is the exact reason why this issue went undiscovered for so long. If it was the system that you say it is, then it would have been constantly making the 2.5-degree adjustments to the horizontal stabilizer all the time! "All the time" is a funny way of spelling "when the AoA sensor indicates an AoA near or greater than critical." Also, the problem took so long to be discovered because Trim has become increasingly automated, relegating any system that modifies it to a second or third order concern for pilots generally. The system wasn't documented explicitly in training materials, and yes, what malfunctions did happen generally happened in less critical phases of flight, and we're quickly recovered from. >The fact is that it requires an AoA sensor to report an attack angle greater than 25 degrees ...Okay, you didn't even look at the Flight Data Recorder of either crash did you? The same data that shows MCAS happily driving 300+ people into the lithosphere at 300+ knots? MCAS activates regardless of speed. The key input is AoA, flap setting, and whether the autopilot is on, and altitude > 450 AGL if I recall correctly. Furthermore, it ramps up over sequential activations. I'm open to entertaining some possibility that you just didn't look it up, but your arguments are straying into areas if incorrectness that seem to indicate your sources may need to be reevaluated. I implore you to do some more thorough research. Search terms: ET302 FDR data ET302 prelim report Lion Air 610 FDR data MCAS Flight Control Systems. I understand Aviation isn't the lightest topic of research, but that's also why it's so important to make sure you're reasoning from the right information. Flying is complicated. Not inaccessibly so, but definitely beyond normal intuition at times.
- blackflame7000 7y ago
  "Also, the problem took so long to be discovered because Trim has become increasingly automated, relegating any system that modifies it to a second or third order concern for pilots generally." > "The problem with automated runaway trim is that trim is automated and pilots don't notice" - your argument in a nutshell "The fact is that it requires an AoA sensor to REPORT an attack angle greater than 25 degrees" > Who said the report needed to be accurate?

salawat 7y ago

>This is false because MCAS only activates during stall conditions and is the exact reason why this issue went undiscovered for so long. If it was the system that you say it is, then it would have been constantly making the 2.5-degree adjustments to the horizontal stabilizer all the time! "All the time" is a funny way of spelling "when the AoA sensor indicates an AoA near or greater than critical." Also, the problem took so long to be discovered because Trim has become increasingly automated, relegating any system that modifies it to a second or third order concern for pilots generally. The system wasn't documented explicitly in training materials, and yes, what malfunctions did happen generally happened in less critical phases of flight, and we're quickly recovered from. >The fact is that it requires an AoA sensor to report an attack angle greater than 25 degrees ...Okay, you didn't even look at the Flight Data Recorder of either crash did you? The same data that shows MCAS happily driving 300+ people into the lithosphere at 300+ knots? MCAS activates regardless of speed. The key input is AoA, flap setting, and whether the autopilot is on, and altitude > 450 AGL if I recall correctly. Furthermore, it ramps up over sequential activations. I'm open to entertaining some possibility that you just didn't look it up, but your arguments are straying into areas if incorrectness that seem to indicate your sources may need to be reevaluated. I implore you to do some more thorough research. Search terms: ET302 FDR data ET302 prelim report Lion Air 610 FDR data MCAS Flight Control Systems. I understand Aviation isn't the lightest topic of research, but that's also why it's so important to make sure you're reasoning from the right information. Flying is complicated. Not inaccessibly so, but definitely beyond normal intuition at times.

blackflame7000 7y ago
"Also, the problem took so long to be discovered because Trim has become increasingly automated, relegating any system that modifies it to a second or third order concern for pilots generally." > "The problem with automated runaway trim is that trim is automated and pilots don't notice" - your argument in a nutshell "The fact is that it requires an AoA sensor to REPORT an attack angle greater than 25 degrees" > Who said the report needed to be accurate?