Fuel flow keps getting weaker during flight without moving throttle.
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When flying, I takeoff at maximum thrust and once at an acceptable altitude, I start to move my throttle so that I get enough fuel flow for takeoff.
I noticed that if I move the throttle back to just a millimeter below where the afterburner would kick in, the fuel flow goes to about 8-9,000 unitsIf I don’t move the throttle, the value keeps reducing to a point that my airspeed continues to fall. (if I don’t do anything, I will stall)
If I move the throttle up (since I was so close to the afterburner kicking in), the after burner kicks in and the fuel flow goes to maximum flow.When I move the throttle back (to that magic level - a millimeter below afterburner level), the fuel flow value goes to about 6,000 units but then continues to fall.
So basically I have to keep going into afterburner state to get to an airspeed that I won’t stall at, then the fuel flow falls until I go back to the afterburner using the maximum fuel flow.
(this cause me an inefficient use of fuel and I feel I don’t get the distance out of a regular tank of fuel that I should).In the setup screen the afterburner (red line) on the throttle setting is set as close to the top as I can get it.
I have also recalibrated my throttle and it still happens.Is there a better way to manage this.
I have missions that I have to reduce my payload so that I can accommodate fuel tanks that I don’t think I would be needing if the fuel flow can be set at about 5, 6, or 7,000 units for the flight to and from the target.
My setup is a Ch Product Fighterstick, throttle and pedals.
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In the setup screen the afterburner on the throttle setting is set as close to the top as I can get it.
You shouldn’t put the afterburner start at the top, but somewhere on the way up. E.g. 75% range for mil power, top 25% for afterburner. The reason you’re using maximum fuel in Afterburner is because there is (almost) no range, say 99-100%, so it goes into full effect immediately.
As for the throttle running back: On my old Saitek X52, I have rotaries that are faulty and even though I don’t move them, they always run down to 0 when I set them at the center position. It didn’t happen when I set it slightly below or above the center, so I just increased the deadzone to 35-65%. That solved it in my case, but not sure if that is possible with a throttle always trying to reach 0. It’s worth a try, I guess?
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Thanks for the reply,I wlll adjust my deadzone as that is sure to be some of the issue.
So are you saying the Afterburner the RED Line, should be set to about 75% to the top of the scale.
What about the green line. That is currently right at the bottom. I don’t know what exactly this is, but I read that you can adjust that by right clicking AB Set in the UI. -
Thanks for the reply,I wlll adjust my deadzone as that is sure to be some of the issue.
So are you saying the Afterburner the RED Line, should be set to about 75% to the top of the scale.
What about the green line. That is currently right at the bottom. I don’t know what exactly this is, but I read that you can adjust that by right clicking AB Set in the UI.Green line is idle detent. To cut off the engine. Only advisable to set when you have a throttle rail/arm that allows you to but it into/outof cutoff position.
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You didnt mention whether you were accending during this process or holding a set altitude
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FYI, fuel flow is not only depending on throttle postion but also on your actual airspeed. The faster you fly, the more the engine will “eat air” and the more it will have to burn fuel for a given throttle setting.
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You didnt mention whether you were accending during this process or holding a set altitude
This happens when I am holding altitude.
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Check the ch manager while you’re flying and see if you have throttle issues
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Green line is idle detent. To cut off the engine. Only advisable to set when you have a throttle rail/arm that allows you to but it into/outof cutoff position.
Wrong, red line is idle detent, green is AB.
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Wrong, red line is idle detent, green is AB.
Could be, answered without bms open and based on respons of topic starter speaking of green line at The bottom.
My bad. -
Could be, answered without bms open and based on respons of topic starter speaking of green line at The bottom.
My bad.NP
On topic : as DJ said, for a given RPM, fuel flow depends on the air flow in the engine. So it varies with speed and with altitude.
Watch the RPM indicator to see if your throttle creeps down…
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When flying, I takeoff at maximum thrust and once at an acceptable altitude, I start to move my throttle so that I get enough fuel flow for takeoff.
In the setup screen the afterburner (red line) on the throttle setting is set as close to the top as I can get it. .
Is there a better way to manage this.
My setup is a Ch Product Fighterstick, throttle and pedals.
What is a acceptable altitude ?
“enough fuel for takeoff” your allready in the air?
Did you fix the “red” / “Green” Line you have them upside down ?
And if you continue to climb in altitude you will stall.
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In the setup screen the afterburner (red line) on the throttle setting is set as close to the top as I can get it.
Wrong, red line is idle detent, green is AB.
Combining these two seems to indicate you had your idle detent set at 99%, so each time you’re below (= pretty much always) you actually shut down your engine, which explains the lack of thrust. In that case, it isn’t a problem with your throttle, but with how you configured the software.
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I noticed that if I move the throttle back to just a millimeter below where the afterburner would kick in, the fuel flow goes to about 8-9,000 units
If I don’t move the throttle, the value keeps reducing to a point that my airspeed continues to fall. (if I don’t do anything, I will stall)
If I move the throttle up (since I was so close to the afterburner kicking in), the after burner kicks in and the fuel flow goes to maximum flow.If I understand your original question: The engine is just a very powerful turbine. It is only able to produce a specific amount of power based on air + fuel supplied. As you continue to climb, the air is thinner and the engine is not able to produce as much power = slower turbine speed = lower fuel supply.
Try zoom climb to 50k feet and see how you almost need to be in full burner just to maintain level flight (almost at stall speed) .
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I will try and adjust the red and green lines.
Currently they are where the red line is almost at the top. (will adjust to be about 10% below the top).
The Green line is at the bottom (will adjust to about 25% above the bottom)Bull,
I usually fly about 25 -30K, I will drop down to 10K on AG runs, but the same fuel bleed is happening. - I normally don’t fly at 50K. -
I will try and adjust the red and green lines.
Currently they are where the red line is almost at the top. (will adjust to be about 10% below the top).
The Green line is at the bottom (will adjust to about 25% above the bottom)Bull,
I usually fly about 25 -30K, I will drop down to 10K on AG runs, but the same fuel bleed is happening. - I normally don’t fly at 50K.Are you 100% sure the red line is on top and the green one down?
Green should be AB, so on top, and red idle cutoff, so on bottom. If you have that upside down, each time you drop a bit below max throttle you are completely shutting down your engine. And when passing cutoff, you are already in full AB since the green one is passed already before that.
That could maybe also explain why you have throttle issues and fuel flow issues. You are either in full AB or without engine. -
Are you 100% sure the red line is on top and the green one down?
Green should be AB, so on top, and red idle cutoff, so on bottom. If you have that upside down, each time you drop a bit below max throttle you are completely shutting down your engine. And when passing cutoff, you are already in full AB since the green one is passed already before that.
That could maybe also explain why you have throttle issues and fuel flow issues. You are either in full AB or without engine.OOps…your right,
The green line is the one on top and the red line is the one on the bottom.So, shouldn’t that mean if my throttle goes above the red line the AF burner kicks in (which it does)
If my throttle is below the green line and above the red line, I should have power. If I am at 85% up over the red line, my fuel flow continues to fall slowly.
If the fuel flow falls to 6-7,000 units flying at 15,000 ft, then the only way to get more power is go into afterburner, where the fuel flow will shoot to the highest numbers, but as soon as I move the throttle to below the AF burner line (green line) it falls right back to 6- 7000 units and continues to fall slowly.I would think that if I have the throttle at about 85% or so, I could get maybe 12- 15,000 units of fuel flow and keep it there, with the exception of atmospheric conditions.
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no green is AB, red is cutoff. So above red = running engine, above green = AB.
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Jack
The Higher you fly the less fuel you will burn. Because the air is thinner. But the drag is also less.
Six or seven thousand is about right for mid alt.
Look at your Mach Speed. and :rtfm:
Had to say that, I was forced by the evil forum troll that lives in my keyboard.
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If the fuel flow falls to 6-7,000 units flying at 15,000 ft, then the only way to get more power is go into afterburner, where the fuel flow will shoot to the highest numbers, but as soon as I move the throttle to below the AF burner line (green line) it falls right back to 6- 7000 units and continues to fall slowly.
I would think that if I have the throttle at about 85% or so, I could get maybe 12- 15,000 units of fuel flow and keep it there, with the exception of atmospheric conditions.
Been kinda said already but your fuel flow also depends on your speed - if you are slowing down the fuel flow will decrease also.