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Discussion online and otherwise about these two accidents focus almost 100% around MCAS and angle of attack (AoA) sensor malfunction + pilot 'error' [due to ins

by rixrax 8y ago

Discussion online and otherwise about these two accidents focus almost 100% around MCAS and angle of attack (AoA) sensor malfunction + pilot 'error' [due to insufficient training]. For the sake of further speculation: what are the chances that in-fact there would be some other contributing factor or indeed a root cause (where MCAS no doubt maybe plays part) that was missed by Lion air incident analysis. Assuming of course that both incidents would have same / similar root cause.

hencq 8y ago
Just saw this after I commented, but I think the chances of that are quite high. I would imagine pilot error is somewhat less likely since so much attention was drawn to MCAS after the Lion Air flight.
ams6110 8y ago
I have seen some suggestion that in the Ethopian crash the crew may have overlooked setting the flaps for takeoff. This would not only reduce lift but also potentially allow MCAS to operate since it only works with flaps retracted. Let me say again this is only speculation as far as I have seen.
- CydeWeys 8y ago
  Surely there's some kind of warning system that alerts if the flaps aren't set for take-off?! That'd be easy to write an alert for -- are the wheels-down sensors triggered, the throttle well above idle, and the flaps up? Fire the alert.
- rixrax 8y ago
  My armchair speculation finds it odd that there is no more discussion around unusually high airspeed and what is causing them early in the flight. E.g. it appears that both JT610 and ET302 hit ~300kts within ~2 minutes of flight[0][1] whereas on problem free takeoffs 300kts appears to be reached at ~4 minutes into the flight at around 10k ft[3][4][5]. So based on this, I would speculate that maybe there is some condition that leads to run-away thrust, makes pilots report 'flight control problem' about 3 minutes into the flight[5][6] and then the rest follows. If the angle suggested above has already been investigated and there is some reporting around this - would appreciate pointer there. [0] https://www.flightradar24.com/data/flights/et302#1fc0cdb5 https://www.flightradar24.com/data/flights/et302#1fc0cdb5 (ET302) [1] https://www.flightradar24.com/data/pinned/jt610-1e5ff318#1e5ff318 https://www.flightradar24.com/data/pinned/jt610-1e5ff318#1e5... (JT610) [2] https://www.flightradar24.com/data/flights/aa2405#1fbc9d44 https://www.flightradar24.com/data/flights/aa2405#1fbc9d44 (AA2405) [3] https://www.flightradar24.com/data/flights/wn2389#1fbd2039 https://www.flightradar24.com/data/flights/wn2389#1fbd2039 (WN2390) [4] https://www.flightradar24.com/data/flights/et302#1fbe5988 https://www.flightradar24.com/data/flights/et302#1fbe5988 (ET302 on Mar 9th) [5] https://en.wikipedia.org/wiki/Lion_Air_Flight_610 https://en.wikipedia.org/wiki/Lion_Air_Flight_610 [6] https://www.reuters.com/article/us-ethiopia-airplane/ethiopia-sends-boeing-black-boxes-abroad-norway-airline-wants-compensation-idUSKBN1QU15W https://www.reuters.com/article/us-ethiopia-airplane/ethiopi...
  - SomeHacker44 8y ago
    In the USA, planes are ordinarily prohibited from flying above 250 knots below 10,000 feet. The caveat is that that is indicated airspeed, not actual (true).

by rixrax 8y ago

hencq 8y ago

Just saw this after I commented, but I think the chances of that are quite high. I would imagine pilot error is somewhat less likely since so much attention was drawn to MCAS after the Lion Air flight.

ams6110 8y ago

I have seen some suggestion that in the Ethopian crash the crew may have overlooked setting the flaps for takeoff. This would not only reduce lift but also potentially allow MCAS to operate since it only works with flaps retracted. Let me say again this is only speculation as far as I have seen.

CydeWeys 8y ago
Surely there's some kind of warning system that alerts if the flaps aren't set for take-off?! That'd be easy to write an alert for -- are the wheels-down sensors triggered, the throttle well above idle, and the flaps up? Fire the alert.
rixrax 8y ago
My armchair speculation finds it odd that there is no more discussion around unusually high airspeed and what is causing them early in the flight. E.g. it appears that both JT610 and ET302 hit ~300kts within ~2 minutes of flight[0][1] whereas on problem free takeoffs 300kts appears to be reached at ~4 minutes into the flight at around 10k ft[3][4][5]. So based on this, I would speculate that maybe there is some condition that leads to run-away thrust, makes pilots report 'flight control problem' about 3 minutes into the flight[5][6] and then the rest follows. If the angle suggested above has already been investigated and there is some reporting around this - would appreciate pointer there. [0] https://www.flightradar24.com/data/flights/et302#1fc0cdb5 https://www.flightradar24.com/data/flights/et302#1fc0cdb5 (ET302) [1] https://www.flightradar24.com/data/pinned/jt610-1e5ff318#1e5ff318 https://www.flightradar24.com/data/pinned/jt610-1e5ff318#1e5... (JT610) [2] https://www.flightradar24.com/data/flights/aa2405#1fbc9d44 https://www.flightradar24.com/data/flights/aa2405#1fbc9d44 (AA2405) [3] https://www.flightradar24.com/data/flights/wn2389#1fbd2039 https://www.flightradar24.com/data/flights/wn2389#1fbd2039 (WN2390) [4] https://www.flightradar24.com/data/flights/et302#1fbe5988 https://www.flightradar24.com/data/flights/et302#1fbe5988 (ET302 on Mar 9th) [5] https://en.wikipedia.org/wiki/Lion_Air_Flight_610 https://en.wikipedia.org/wiki/Lion_Air_Flight_610 [6] https://www.reuters.com/article/us-ethiopia-airplane/ethiopia-sends-boeing-black-boxes-abroad-norway-airline-wants-compensation-idUSKBN1QU15W https://www.reuters.com/article/us-ethiopia-airplane/ethiopi...
- SomeHacker44 8y ago
  In the USA, planes are ordinarily prohibited from flying above 250 knots below 10,000 feet. The caveat is that that is indicated airspeed, not actual (true).