71–80 of 272 posts
They shouldn't have to do this routinely.
One of the factors that has been quickly glossed over is the low level of experience of some of the pilots in both the Indonesian and Ethopian accidents. In the USA, due to much higher levels of experience pilots have been correcting for the MCAS actions effectively and complaining about it to NASA (in order to avoid being branded as whistle-blowers by their airlines).
Why is it kept in a water-filled box in the image on the news article? Feels freaky like it is a living animal kept alive in an aquarium. edit> https://www.quora.com/Why-are-black-boxes-put-into-water-aft...
Earlier quoted context omitted.
And sounds ? The trim wheels moving also makes a sound?
You'll note in that video, the left-hand pilot has a headset on, presumably the right-hand pilot does too. Headsets are seen in other videos [1] of the cockpit. So even if the spinning trim wheels make noise, they may not have heard it. (My google image search shows some pilots wearing two-ear headsets, some wearing one-ear headsets, some wearing two-ear headsets with side not on their ear, and some not wearing heads…
Having a headset on doesn't stop you hearing noises in a cockpit. How did you think all the other verbal alarms and callouts worked if they can't hear anything?
I'm trying to imagine the horror the pilots (and passengers) were feeling. Imagine your car slowly starting to shift sideways into incoming traffic, and no matter how hard you pull the steering wheel, you can't get it back. Horrifying.
This is why I refuse to listen to these things when they're released. The thought of eavesdropping in on someone's frantic hopeless fight for survival just doesn't sit right with me.
One of the factors that has been quickly glossed over is the low level of experience of some of the pilots in both the Indonesian and Ethopian accidents. In the USA, due to much higher levels of experience pilots have been correcting for the MCAS actions effectively and complaining about it to NASA (in order to avoid being branded as whistle-blowers by their airlines).
How would it even be possible for US pilots to sustainably have „much higher levels of experience“? Do non-US pilots fly only two days a week? Do they all die before age 40? This stereotype of dingy third-world airlines with incompetent, untrained pilots borders on racism. At the very least, one should notice that flying the world’s newest airliner in significant numbers is incompatible with one‘s preconceptions.
Southwest Airlines, for example requires:
> Flight Experience: 2,500 hours total or 1,500 hours Turbine total. Additionally, a minimum of 1,000 hours in Turbine aircraft as the Pilot in Command* is preferred. Southwest considers only Pilot time in fixed-wing aircraft. This specifically excludes simulator, WSO, RIO, FE, NAV, EWO, etc. "Other Time" will not be considered.
https://swa.pilotcredentials.com/index.php?a=qualifications
Delta requires:
> Minimum of 1,500 hours of total documented flight time.
> Minimum of 1,000 hours of fixed wing turboprop or turbofan time.
> 90% of the flight time logged in powered lift category aircraft (e.g. AV-8B, F-35B, and V-22) will be credited to the Delta Air Lines 1,000 hour fixed wing turboprop/turbofan requirement.
> Minimum of 250 hours PIC in an aircraft categorized as an airplane.
> The flight time logged in a powered lift category aircraft cannot be credited towards PIC aircraft time in accordance with 14 C.F.R. 61.159.
> Minimum of 50 hours of fixed wing multi-engine time.
https://www.deltajobs.net/pilot_qualifications.htm
United requires:
> Minimum of 1,000 hours of fixed-wing turbine time
https://www.united.com/ual/en/us/fly/company/career/pilot.ht...
The European carriers, on the other hand, do not have such strict requirements.
This appears to answer the question of why, given that there is a "memory item" for dealing with runaway trim that would have helped, it wasn't followed by the crew: > “They didn’t seem to know the trim was moving down,” the third source said. “They thought only about airspeed and altitude. That was the only thing they talked about.” If this is true, not only did the pilots not realize the trim was the cause of the d…
Thinking about that I wonder whether there was even a measurement signal that the computers could rely on to determine the current state of the trim angle in absolute terms.
Given how the MCAS did incremental changes without stopping before reaching the mechanical limits, I do imagine that there might have been no hardware feedback to assess the current trim state, thereby making it impossible hardware-wise to limit MCAS to a sensible (and safe) range of angles.
[edit] Looking at the lion air crash report [1] p.14 ff it seems like also the black box only recorded trim changes, not absolute trim state.
[1] https://reports.aviation-safety.net/2018/20181029-0_B38M_PK-...
What I don't understand whenever I read anything related to the MCAS system is why does it not check if the plane is in a dangerous nose dive using other sensors the plane might have? Does the average plane not have a gyroscope? My sub 500 dollar phone has both a gyroscope and an inertial measurement unit (accelerometer).
Gyroscopes by themselves can not sense the orientation of a body moving through three dimensions.
Earlier quoted context omitted.
Was the trim wheel not visibly spinning out of their control? Simply because the symptoms are different should mean that stopping it via taking manual control is a recurring option.
To my understanding, the trim wheels are moving frequently for small adjustments -- and it's possible to switch the wheel movement off if this becomes too annoying.
It not possible to disable wheel movement. It's mechanically linked to the jackscrew.