Weather-sensitive auto-thrust ?
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Join Date: May 2007
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Weather-sensitive auto-thrust ?
Question from a non pilot,
As I switched to a more realistic simulator software, I realized that in turbulence weather, auto-thrust doesn't work well because the too frequent corrections it makes, especially in approach and landing.
I understand this is also the case in real a/c.
So I was curious, hasn't anyone developed some kind of correction in the A/T so that when weather requires, or other applicable conditions, it does less frequent corrections, resembling more the "steadier" hand of a pilot ?
Perhaps, something in the above problem has anything to do with operating A/T in which a certain target N1 (or other parameter) is set instead of IAS ? In my ignorance I don't fully grasp that mode of operation.
Thanks for answering you have spare time!
As I switched to a more realistic simulator software, I realized that in turbulence weather, auto-thrust doesn't work well because the too frequent corrections it makes, especially in approach and landing.
I understand this is also the case in real a/c.
So I was curious, hasn't anyone developed some kind of correction in the A/T so that when weather requires, or other applicable conditions, it does less frequent corrections, resembling more the "steadier" hand of a pilot ?
Perhaps, something in the above problem has anything to do with operating A/T in which a certain target N1 (or other parameter) is set instead of IAS ? In my ignorance I don't fully grasp that mode of operation.
Thanks for answering you have spare time!
Join Date: May 2003
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autothrust
hello el#
in light to moderate turbulence the system autothrust/autopilot can cope with the situation, although at a higher pace, eg : more frequent thrustlever movements resulting in a less confortable ride. if the turbulence is such that the system can't cope with it anymore, then the boeing manual(& common sense), recommends to switch the autothrust off & set an average N1( on fms cruise page you find the recommended cruise turbulence N1) & fly an average of the recommended turbulence penetration speed. further if conditions warrant, you can disconnect the altitude hold function of the autopilot by switching to cws pitch mode. advise atc of possible altitude/fl deviations. have the seatbelts on, cabin crew seated, loose articles stowed, engine start switches in continuous ignition etc. during approach in turbulent conditions the system is supposed to automatically adjust to a higher N1 & targetspeed. above all try to get out of turbulence as quick as possible by climb/descent to a more confortable altitude.(descent preferred as climbing reduces the margin between high/low stall speed). total air temperature(TAT) fluctuation are an indication for possible turbulence ahead, also ask for or listen to turbulence reports of aircraft ahead of your route.
happy landings,
bm
in light to moderate turbulence the system autothrust/autopilot can cope with the situation, although at a higher pace, eg : more frequent thrustlever movements resulting in a less confortable ride. if the turbulence is such that the system can't cope with it anymore, then the boeing manual(& common sense), recommends to switch the autothrust off & set an average N1( on fms cruise page you find the recommended cruise turbulence N1) & fly an average of the recommended turbulence penetration speed. further if conditions warrant, you can disconnect the altitude hold function of the autopilot by switching to cws pitch mode. advise atc of possible altitude/fl deviations. have the seatbelts on, cabin crew seated, loose articles stowed, engine start switches in continuous ignition etc. during approach in turbulent conditions the system is supposed to automatically adjust to a higher N1 & targetspeed. above all try to get out of turbulence as quick as possible by climb/descent to a more confortable altitude.(descent preferred as climbing reduces the margin between high/low stall speed). total air temperature(TAT) fluctuation are an indication for possible turbulence ahead, also ask for or listen to turbulence reports of aircraft ahead of your route.
happy landings,
bm
Last edited by blackmail; 28th Oct 2007 at 10:21.
