An-148 missing after takeoff from Moscow
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Based on what I read so far, and thanks to Flocks especially , above , lets turn on the speculation mode :
They seem to have "forgotten" to manually turn on the heater(s) as I do not think with the weather at the time one would have done this voluntarily. Now the system , as I understood it, should have generated 3 ECAM yellow warnings .
Maybe ( speculating) those messages were not visible because of possibly another warning , that superseded those in the priority tree, and that warning was OK on the MEL.
We do not know enough about the Russian avionic ECAM logic , but that could have added a hole in the cheese layers.
They seem to have "forgotten" to manually turn on the heater(s) as I do not think with the weather at the time one would have done this voluntarily. Now the system , as I understood it, should have generated 3 ECAM yellow warnings .
Maybe ( speculating) those messages were not visible because of possibly another warning , that superseded those in the priority tree, and that warning was OK on the MEL.
We do not know enough about the Russian avionic ECAM logic , but that could have added a hole in the cheese layers.
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Kulverstukas, if I may impose on your time, where are the pitot heat switches located, (overhead panel, I suspect, but where?). Also, I assume they are set to "ON" using either the after-start or before-takeoff checklist; would those checklists be available?
I understand each air carrier may develop their own checklists but the manufacturer's checklists would likely be available, would they?
I understand each air carrier may develop their own checklists but the manufacturer's checklists would likely be available, would they?
(3) Heating CHECK
Checklist AT LINEUP (BEFORE TO)
Pitot heating ..... ON
Warnings .......... NONE
Time allowed of Pitot heating on the ground .... 2 min
Time before Pitot OVERHEAT warning ... 5 min
Manufacturer data of max time of heating without external cooling ... 10 min
UPD: OVERHEAT on-ground warning is linked to LMG ground sensor
Last edited by Kulverstukas; 21st Feb 2018 at 10:10. Reason: UPD added
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So, if I understand it correctly, pitot heat is required at all times whilst an aircraft is in the air. Why not link it in with the WOW switches, using the logic that if WOW = OFF, then Pitot Heat = ON ?
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Super VC-10
Pitot system on this plane is exactly the same used on Yak-42. You don't think that any design bureau develops their own and not just buy which available at the market?
There was no known accidents on Yak-42 because of Pitot heating so far.
Pitot system on this plane is exactly the same used on Yak-42. You don't think that any design bureau develops their own and not just buy which available at the market?
There was no known accidents on Yak-42 because of Pitot heating so far.
That is basically how it works in the CRJ (at least from 700 onwards, don’t know about the 200 and before). We can mess with the switches all we want, but taking off with the switches in off position doesn’t matter, it will go to full heat anyway.
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Why not link it in with the WOW switches, using the logic that if WOW = OFF, then Pitot Heat = ON ?
If we are debating automated pitot heat I’ll chuck into the mix that on some types it’s any engine engine running = pitot on....(with an EICAS message if it fails).
Having the trigger for heat being handbrake release means the probe heat is on for towing ops, which may not be desirable on some types and certainly could get messy if the aircraft is towed for maintenance purposes with the covers on...
Having probe heat being turned on at a particular thrust setting above idle could IMHO cause probs in icing conditions on the ground or early on in the takeoff role....on some types on the ground you only nudge the power up to start taxiing, most of the time you are taxiing with the thrust back at idle.
Having the trigger for heat being handbrake release means the probe heat is on for towing ops, which may not be desirable on some types and certainly could get messy if the aircraft is towed for maintenance purposes with the covers on...
Having probe heat being turned on at a particular thrust setting above idle could IMHO cause probs in icing conditions on the ground or early on in the takeoff role....on some types on the ground you only nudge the power up to start taxiing, most of the time you are taxiing with the thrust back at idle.
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IMO, not the best design. During taxi the pilots can get unexpected delay, switch off the pitot heating in order to stay within limit, and then, after being distracted by radio communication, simply forget to switch it on.
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Then they must skip Befote TO checklist point about pitot heating (post #223, second red line) and dismiss three yellow warnings on screen (post #223, third red line) and three "OFF" lights on overhead pannel (post #223, pos (2)).
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This is not correct, "we need to consult with ground" on ATC recording belongs to different flight.
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No I did not mean like a phone app. I believed it was a genuine question to ask.
Having a hole drilled into the side of a plane that is 18th century technology seems a little bit archaic.
The space shuttle didn't have pitot tubes and they had her velocity to a tea in orbit.
from the boffins that have given us hover boards and tractor beams, maybe there could be a better way. Like I said.
Having a hole drilled into the side of a plane that is 18th century technology seems a little bit archaic.
The space shuttle didn't have pitot tubes and they had her velocity to a tea in orbit.
from the boffins that have given us hover boards and tractor beams, maybe there could be a better way. Like I said.
Err.......looks like in reality when it came to aerodynamic flight at lower altitudes the boffins didn’t have a better way...
https://spaceflight.nasa.gov/shuttle...s/gnc/ads.html
https://spaceflight.nasa.gov/shuttle...s/gnc/ads.html