Fuel flow keps getting weaker during flight without moving throttle.
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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 downâŚ
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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 ?
âenough fuel for takeoffâ your allready in the air?
Did you fix the âredâ / âGreenâ 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 youâre below (= pretty much always) you actually shut down your engine, which explains the lack of thrust. In that case, it isnât 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 donât move the throttle, the value keeps reducing to a point that my airspeed continues to fall. (if I donât 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 donât 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 donât 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.OOpsâŚyour right,
The green line is the one on top and the red line is the one on the bottom.So, shouldnât 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.