Timeline for Why does the KC-46 use two sensors for MCAS when the 737 Max doesn’t?
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Dec 2, 2021 at 11:54 | comment | added | MacGuffin | @PeterKämpf I know that the FAA was not aware of the implications of the changes made to MCAS on the 737MAX. Again, the question was, why would the FAA agree to this? The answer, they were not aware of the implications. I am quite aware of the flaws in the system to verify that MCAS was not a safety hazard. Because they did not know of this the FAA agreed that there was no need for a redundant AoA sensor input to MCAS. I addressed your complaint already, why repeat it? What do you want from me? | |
| Dec 2, 2021 at 9:27 | comment | added | Peter Kämpf | "why ... the FAA would agree to this decision" This was entirely because the FAA learned only after the crashes of the modifications to MCAS. All previous certification work was done by Boeing employees. If you had followed the link you would have learned that "Boeing Authorized Representatives are Boeing employees who are granted special permission to represent the interests of the FAA and to act on the FAA’s behalf in validating aircraft systems and designs’ compliance with FAA requirements". | |
| Dec 1, 2021 at 22:22 | comment | added | MacGuffin | " Your downplaying of the 737MAX MCAS paints a wrong picture. " I'm not downplaying the severity of the 737MAX MCAS problems, I'm answering the question on why Boeing would decide to have a single AoA sensor for MCAS and the FAA would agree to this decision. This was done because at the time MCAS was not seen as safety critical or posing a safety problem of its own. We know now this was not true but that's 20/20 hindsight. | |
| Dec 1, 2021 at 19:31 | comment | added | Peter Kämpf | Your downplaying of the 737MAX MCAS paints a wrong picture. While the MCAS of the KC-46 corrected stabilizer trim only once and only by 0.6 degrees, the 737MAX MCAS would do so repeatedly and by a much larger amount of 2.5 degrees of trim until AoA would drop below its limit (I believe that was 8 degrees). With a sensor malfunction this required reaction within 4 seconds to follow the procedure for trim runaway. | |
| Dec 1, 2021 at 3:53 | history | answered | MacGuffin | CC BY-SA 4.0 |