3 ms·
If you're not trained on the MCAS feature, an "AOA disagree" indicator is going to tell you what? That stall warning may not work reliably? There's more going
by cmurf 8y ago
If you're not trained on the MCAS feature, an "AOA disagree" indicator is going to tell you what? That stall warning may not work reliably?
There's more going on here than just MCAS and angle of attack sensors though. From the KNKT preliminary report:
At 23:31:09 UTC, the LNI610 PIC advised the ARR controller that the altitude of the aircraft could not be determined due to all aircraft instruments indicating different altitudes.
Crash happens 45s later. (More correctly, the FDR stops recording.)
From the same report, four separate maintenance records containing one or more defects in: indicated airspeed, indicated altitude, speed trim fail, mach trim fail. These were reported by multiple crew, repaired by maintenance per manufacturer procedure, and tested, and error state cleared.
The stick shaker was active for all of Lion Air 34 and most of 610. That is not an airworthy aircraft, and the preliminary report states this.
Obviously something does not pass the smell test. Either there's a very serious problem with the prescribed repair and verification procedure. Or there's a very serious crime if the claimed repairs and/or verification are inauthentic. Both seem incredible to me.
Common to airspeed and altimeter is the static system.
But as a pilot what really gets my attention, and not in a good way, is that apparently automation is confused, detecting multiple current sensor disagreements and flags, and yet it's still taking action.
- olliej 8y agoRight? Especially given (per media so grain of salt maybe?) the Mcas system was essentially engaged by a single sensor - implying a single sensor capable of overriding all other systems, even the ones with actual redundancy. I still don’t understand why altitude wasn’t considered - surely stalling speed close to the ground would result in less damage than pitching towards the ground an accelerating? And how much can those sensors possibly cost anyway? (Real question - I have no sense if we’re talking a few dollars, a few thousand, few million, or what)