An-148 missing after takeoff from Moscow
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If you want to discuss automation of pilot heating, welcome to aviaforum.ru, there are over 170 pages on this in An-148 thread now.
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Kulverstukas
I am okay with manual switches.
The point is. Regardless to the origin of this malfunction. (Which is so far attributed to the pilots inability to follow checklist and they nonexistent response to the warning lights)
This was a sensor malfunction! Something literally stopped working.
(Moreover, poisoning other instruments with misleading data flow )
This can't be right.
This is critical to flight instrument and you can easily theorize a lot of situation in which the clear knowledge about Pitot tubes malfunction couldn't be substituted by "your speed is messed up" warning.
I am okay with manual switches.
The point is. Regardless to the origin of this malfunction. (Which is so far attributed to the pilots inability to follow checklist and they nonexistent response to the warning lights)
This was a sensor malfunction! Something literally stopped working.
(Moreover, poisoning other instruments with misleading data flow )
This can't be right.
This is critical to flight instrument and you can easily theorize a lot of situation in which the clear knowledge about Pitot tubes malfunction couldn't be substituted by "your speed is messed up" warning.
Once again we must understand the control laws on these FBW fxlight control systems to come up with or actually determine a "cause".
- Upon determining unreliable air data, the Viper I flew all those years ago used one of two "gain" values depending upon gear up/down. So body rates and AoA became more important in the computer algorithm. We even had one guy flt for 7 or 8 minutes with ZERO air data and no AoA probes due to a 40 pound bird strike on the nose.
- The Airbus longitudinal control algorithm uses pitch attitude and roll to modify the gee command. Also has the AoA input to "keep you from stalling". Such an implementation in this case may have helped a lot depending on all the reversion sequences. Hell, we went thru all this for a year on the "other" thread.
Hopefully, this accident will provide a strng basis for much better training and maybe even some control law improvements as well as better alert indications.
- Upon determining unreliable air data, the Viper I flew all those years ago used one of two "gain" values depending upon gear up/down. So body rates and AoA became more important in the computer algorithm. We even had one guy flt for 7 or 8 minutes with ZERO air data and no AoA probes due to a 40 pound bird strike on the nose.
- The Airbus longitudinal control algorithm uses pitch attitude and roll to modify the gee command. Also has the AoA input to "keep you from stalling". Such an implementation in this case may have helped a lot depending on all the reversion sequences. Hell, we went thru all this for a year on the "other" thread.
Hopefully, this accident will provide a strng basis for much better training and maybe even some control law improvements as well as better alert indications.
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The track of 045 is just FR24's incorrect interpretation when, as in this case, an aircraft sends zero values for the two ADS-B airborne velocity components (N-S and E-W).
The absence of any groundspeed in the ADS-B data, once airborne, is for the same reason.
The absence of any groundspeed in the ADS-B data, once airborne, is for the same reason.
Rob
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Kulverstukas : thanks for that video on the An148 cockpit . The avionics look very " Western": one questions if I may : what is the large red handle for on the left of the FMS ?
Last edited by ATC Watcher; 19th Feb 2018 at 09:57. Reason: one question already answered in previous post
They are very helpful to those of us that are technically interested but not pilots...
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Thank you Kulverstukas for the explanation . On the aircraft I fly/flew, the parking brake was always a small insignificant grey or black lever. Do you know why it is so prominent in the An148? Is there a specificity that makes it so important ?
And are the forgotten on/switch for the sensors heaters a prominent one(s) of a standard square one with an illuminated bar, like the many that we see on the video.
And are the forgotten on/switch for the sensors heaters a prominent one(s) of a standard square one with an illuminated bar, like the many that we see on the video.
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I am not a pilot, but why would an aircraft designer not automatically have the pitot heating turned on if needed instead of a manual item on a checklist?
Somewhere here I read AN148 has a pitot heating element which would overheat on grd/still air. But I understand your concern, it's not rocket science to have a sensor in it for temp reg.
BTW even the airbus changes heating mode concerning grd/inflight, but yes it's fully automatic.
BTW even the airbus changes heating mode concerning grd/inflight, but yes it's fully automatic.
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Pitot heat on when parked will overheat and cause burns if anyone accidentally touches it.
Therefore it needs to be turned on for taxi and definitely on for T/O. Different manufacturers have come to different solutions for handling this. Yes auto on for T/O if not already would seem the most logical and safe.
Therefore it needs to be turned on for taxi and definitely on for T/O. Different manufacturers have come to different solutions for handling this. Yes auto on for T/O if not already would seem the most logical and safe.
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?
Many thanks per your fine contributions.
I understand each air carrier may develop their own checklists but the manufacturer's checklists would likely be available, would they?
Many thanks per your fine contributions.
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would seem the most logical and safe.
The Spanair accident in Madrid was (partly) caused by such an automatic failing.
It probably is a philosophical question, but having the pilot in the loop will increase awareness, any automation creates a potential for being taken for granted, and being missed in case of failure.
So you have to add an automatic monitoring and warning to the automatic pitot heat, just increasing complexity.
it's not rocket science to have a sensor in it for temp reg.
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Plane I currently fly, Pitot heat are with a manual switch overhead panel.
We have 3 differents caution warning (yellow) associated to each heating element.
We switch the pitot on, before takeoff and off after vacating rwy. If taxi is planned to be long in bad ground potential icing condition (Amsterdam rwy 36L for exemple), on cpt decision, pitot heater can be turned on for taxi.
Just to say, I don't see the problems of manual or automatic. If we forgot with the checklist, I ll have 3 big yellow warning. Takeoff without warning is a mandatory SOP in my airline. We will go only if a warning is already known and under MEL.
We have 3 differents caution warning (yellow) associated to each heating element.
We switch the pitot on, before takeoff and off after vacating rwy. If taxi is planned to be long in bad ground potential icing condition (Amsterdam rwy 36L for exemple), on cpt decision, pitot heater can be turned on for taxi.
Just to say, I don't see the problems of manual or automatic. If we forgot with the checklist, I ll have 3 big yellow warning. Takeoff without warning is a mandatory SOP in my airline. We will go only if a warning is already known and under MEL.