Aces High Bulletin Board
Help and Support Forums => Help and Training => Topic started by: Muzzy on August 31, 2010, 11:32:37 PM
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Is there a quick way to figure out how long it will take you to get from one location to the next? With my new emphasis on survival, I kinda need to know when it's time to RTB.
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Which plane. U heavy, light. U vulching , picking. Post more details. planes are like cars more u have throttle floored faster gas is used.
Semp
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Don't know if there is an easier way..but I go offline and time from sector to sector N-S NE-SW, from take off at a set climb rate N-S, NE-SW etc etc with all different load outs ...generally speaking though I found at 300 it takes 5 mins to cross a sector 8 mins to cross it diagonally... the mark of the plane to reference is the back of the wings on your icon...
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Remember the sectors are 25 x 25 miles, use that to make estimations on distance, then use your E6B. If you really want to plan ahead, you could calculate the fuel you will use at a certain manifold and rpm and egress out when you get to that fuel level. Do a little math and you should be fine, there is not magic solution, unless you type into the text buffer, ".GPS"
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Will that be .GPS plus press enter 3 times?
Semp
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Will that be .GPS plus press enter 3 times?
Semp
.gps plus 3x Enter is an option, you will be given a hand help GPS with the locations of enemies on it. Rather than the standard .45, you carry a shoulder-launched surface to air missile that you can re-arm up to 20 times. Also, rather than the usual walking everywhere, you can press a button the GPS to have a WWII helicopter come pick you up and drop you off at any location on the map.
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Muzzy, do this.
In an unused portion of the arena, launch at 25%, and open the E6B. Set your manifold and RPM to the various power settings shown, and see what the E6B says for range and flight duration once your speed stabilizes. Finally, determine absolute minimum power setting to remain level at best glide speed (this isn't shown, you'll have to test to determine it.) Bear in mind that while in real life you couldn't use some combinations of throttle and RPM, in AH, you - at least in all the aircraft I've tested - get the best endurance by running max throttle and adjusting RPM towards minimum until you reach minimum RPM, and then reduce the throttle if you need to reduce power further.
This will give you a good sense for how much fuel you'd need, under various "levels of threat". At the 2x burn rate used in the MA, in some aircraft you need a quarter tank, some times more, to go 1 sector if you have to run flat out. In most aircraft, a quarter tank will take you 3 to 4 sectors if you can run level at absolute minimum power. So there isn't a hard and fast answer as to when you're Bingo, it's going to depend on how much time you can take getting out of Dodge.
Finally, make sure you are aware that some arena's burn fuel at different rates than others, and take that into account. The MA burns fuel as twice the "normal" rate.
<S>
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There are two fuel levels that should be of concern.
The first is "Joker" fuel. Joker fuel is a defined fuel state basically meaning you have just enough fuel to complete the mission and is defined according to the mission.
In our squadron for fighter sweep activity it was defined as the fuel state at which one could return to base at full power with 10 minute fighting reserve. This was for event type flying but it is helpful to have an idea of joker fuel in the main arena.
Its pretty easy to estimate joker fuel. Most late war fighters are in the 300 mph speed range or 5 miles a minute. 5 Minutes to cross a 25 mile grid. So its time to head home with "Joker" fuel when the E6B says the minutes you have at full power is equal to the grids you need to cross + 2 divided by 5.
So if you are 2 grids from home you need 20 minutes of gas for "Joker" fuel as defined with 10 minute fighting reserve.
That is a rough estimate for a fast late war bird. Slower fighters need 6 minutes to cross a grid so the same distance and reserve will result in the need for 22 miuntes on the in game E6B.
Bingo fuel is the other fuel state. If you get below "Joker" you need to know when you reach the point that you have only enough gas to get home. My squadron defined Bingo fuel as the fuel required to get home from the target area at maximum cruise at best altitude.
This is something that requires some thought and planning before you ever takeoff. You need to know the true airspeed at maximum cruise settings and the fuel burn in gallons per hour to calculate a good Bingo number.
In the Main Arena a good Bingo number is Joker without the 10 minute reserve. 5 minutes per grid at full power and you should head home.
It is easy enough to pull up the clipboard and take a look at your minutes fuel remaining at full power. One of the first post takeoff tasks for me is opening the clipboard and clicking on E6B so that each time I pull up the clipboard the E6B info is presented. I have it on a key on my throttle so I can quickly look at my fuel state.
Just review.....
For late war fighters, 5 minutes a grid plus 10 minutes....time to think about bugging out
5 minutes a grid and no extra........................ ..................Time to BUG OUT.
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La's load 100% fuel, climb to 6-8k, level, go to max cruise.
Aprox 1 min before engaging go full throttle & rpm. Keep the fight short and sweet, keep an eye on your e6b.
Should be good for 30 - 45 min total time. I believe La full throttle flight time at Main burn rate is about 25 min.
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Muzzy, do this.
In an unused portion of the arena, launch at 25%, and open the E6B. Set your manifold and RPM to the various power settings shown, and see what the E6B says for range and flight duration once your speed stabilizes. Finally, determine absolute minimum power setting to remain level at best glide speed (this isn't shown, you'll have to test to determine it.) Bear in mind that while in real life you couldn't use some combinations of throttle and RPM, in AH, you - at least in all the aircraft I've tested - get the best endurance by running max throttle and adjusting RPM towards minimum until you reach minimum RPM, and then reduce the throttle if you need to reduce power further.
This will give you a good sense for how much fuel you'd need, under various "levels of threat". At the 2x burn rate used in the MA, in some aircraft you need a quarter tank, some times more, to go 1 sector if you have to run flat out. In most aircraft, a quarter tank will take you 3 to 4 sectors if you can run level at absolute minimum power. So there isn't a hard and fast answer as to when you're Bingo, it's going to depend on how much time you can take getting out of Dodge.
Finally, make sure you are aware that some arena's burn fuel at different rates than others, and take that into account. The MA burns fuel as twice the "normal" rate.
<S>
This is golden :aok
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La's load 100% fuel, climb to 6-8k, level, go to max cruise.
Aprox 1 min before engaging go full throttle & rpm. Keep the fight short and sweet, keep an eye on your e6b.
Should be good for 30 - 45 min total time. I believe La full throttle flight time at Main burn rate is about 25 min.
What's max cruise?
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What's max cruise?
Manifold and RPM settings are displayed in your E6B for various levels of power. Max cruise would be maximum fuel economy by setting your manifold and RPM to correct levels. You'll slow down but it can dramatically extend fuel time. The settings are different for each plane.
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I Just look at my fuel tank when I arrive at the base/fight I'm heading to and see how much I've burned getting there, lets say 25%. I make a mental note to leave before my fuel reaches 25% left. Although if you fly the 38 and go one engine with Max cruise on your way home, you can stay almost as long as you'd like!
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Dude the max cruise saved my life after a marathon chase of some Lancasters last night! Much obliged.
-Muzzy
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On a related note, the propeller control in AH seems to do some odd things, when you're close to the maximum speed in a given plane. This only seems to happen at high speeds: If I fly at full throttle and max RPM, and get up near to the plane's top cruising speed, I can pull the prop back to idle, but the engine won't lose any RPM, and I won't slow down (at least not much), but the fuel consumption drops way back.
I don't have a lot of complex time in real life, but generally, when I move the prop lever back, I see a drop in RPM, regardless of airspeed (admittedly I've only done this in a Piper Arrow, which is certainly not capable of the sort of speeds we see in AH). Is there something weird with the engine modeling in AH, or is this just a phenomenon of being in a constant speed prop aircraft flying at 400 mph (or something else).
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Roadblock,
You are confusing things here.
In the Piper Arrow you have RPM and Manifold Pressure.
Aces High has the same setup.
RPM is propeller RPM (and engine RPM on a direct drive engine)
Manifold pressure is Power
Prop lever controls RPM.
Throttle controls Manifold Pressure (or boost for the British)
It works exactly the same in AH as it does in real life (except for the possibility of overboosting and blowing jugs off the engine)
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Roadblock,
You are confusing things here.
In the Piper Arrow you have RPM and Manifold Pressure.
Aces High has the same setup.
RPM is propeller RPM (and engine RPM on a direct drive engine)
Manifold pressure is Power
Prop lever controls RPM.
Throttle controls Manifold Pressure (or boost for the British)
It works exactly the same in AH as it does in real life (except for the possibility of overboosting and blowing jugs off the engine)
No, I know the difference. Perhaps I wasn't clear in my original post. Try this (I can't test it myself at work to be absolutely certain, but I'm 90% sure these are the steps):
Take off in a 190D, climb up to 15k-20K feet.
Throttle (MP) and RPM (propeller) both to full.
Let the plane accelerate to 390+ TAS.
Now, open the E6B and slowly dial back the propeller control to minimum. Note that the RPM doesn't change, nor does your airspeed, but the fuel burn drops significantly.
I'm asking "is this supposed to happen"? This is certainly a big no no from what I've been taught (high MP settings with low RPM), so I've never tried in an actual airplane and thus I don't know what actually happens.
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I have located the source of confusion.
There is no RPM gauge on the E6B in game. Those are just a list of power settings for the aircraft. They do not change. Consider it the POH section. E6B is a confusing name for the clipboard performance info.
As for the airspeed changing when you decrease RPM at full power. ...
The airspeed should increase and it does unless you are above the speed that can be sustained by max power and maximum coarse pitch on the propeller. The increase in speed is minor and this holds true in real airplanes as well.
Of course, you only get to pull back the prop with full throttle at higher altitudes where the engine can't overboost itself (non-super or turbo charged).
Climb that Arrow up to 10,000 feet and you will be full throttle and pulling the prop back for cruise. You might get 2 knots extra after about 20 minutes.
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I have located the source of confusion.
There is no RPM gauge on the E6B in game. Those are just a list of power settings for the aircraft. They do not change. Consider it the POH section. E6B is a confusing name for the clipboard performance info.
As for the airspeed changing when you decrease RPM at full power. ...
The airspeed should increase and it does unless you are above the speed that can be sustained by max power and maximum coarse pitch on the propeller. The increase in speed is minor and this holds true in real airplanes as well.
Of course, you only get to pull back the prop with full throttle at higher altitudes where the engine can't overboost itself (non-super or turbo charged).
Climb that Arrow up to 10,000 feet and you will be full throttle and pulling the prop back for cruise. You might get 2 knots extra after about 20 minutes.
I only referenced bringing up the E6B so you could observe the fuel consumption decrease.
I still don't think I've correctly explained my question.. bear with me!
My understanding of constant speed propeller behavior is as follows (from the FAA Airplane Flying Handbook):
Pulling back on the
propeller control causes the propeller blades to move
to a higher angle. Increasing the propeller blade angle
(of attack) results in an increase in the resistance of the
air. This puts a load on the engine so it slows down. In
other words, the resistance of the air at the higher blade
angle is greater than the torque, or power, delivered to
the propeller by the engine, so it slows down to a point
where the two forces are in balance.
When an airplane is nosed up into a climb from level
flight, the engine will tend to slow down. Since the
governor is sensitive to small changes in engine r.p.m.,
it will decrease the blade angle just enough to keep the
engine speed from falling off. If the airplane is nosed
down into a dive, the governor will increase the blade
angle enough to prevent the engine from overspeeding.
and
The range of possible blade angles is termed the
propeller’s governing range. The governing range is
defined by the limits of the propeller blade’s travel
between high and low blade angle pitch stops. As long
as the propeller blade angle is within the governing
range and not against either pitch stop, a constant
engine r.p.m. will be maintained. However, once the
propeller blade reaches its pitch-stop limit, the engine
r.p.m. will increase or decrease with changes in
airspeed and propeller load similar to a fixed-pitch
propeller. For example, once a specific r.p.m. is
selected, if the airspeed decreases enough, the
propeller blades will reduce pitch, in an attempt to
maintain the selected r.p.m., until they contact their
low pitch stops. From that point, any further
reduction in airspeed will cause the engine r.p.m.
to decrease. Conversely, if the airspeed increases,
the propeller blade angle will increase until the
high pitch stop is reached. The engine r.p.m. will
then begin to increase.
If we don't see an RPM drop when we pull the prop control back, while cruising at high speed, then (to me) that implies the prop blade angle is already at its maximum limit. If this is true, why does the fuel burn keep decreasing as we continue to move the propeller control back?
If we had a mixture control, and could lean it ourselves, then I could see the fuel burn changing in this way. The behavior I'm seeing just doesn't make sense to me! :(
That make more sense?
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I think you have found a bug Roadblock but I doubt it will get fixed.
I went into the DA and dove a 190D and the propeller does not hold its RPM setting (Which is realistic..the wind will drive the prop at high speed) but the fuel flow does not increase with RPM
It took me quite a while to get wrapped around what you were trying to say because I was doing all the testing in level flight and everything was working like it is supposed to. It was only when diving that the issue becomes obvious. RPM increases above setting but fuel flow does not (and it should increase).
I'll write it up in the bug forum but it shouldn't be a high priority to get fixed as it affects very little. You shouldn't be diving with the prop back very often.
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I think you have found a bug Roadblock but I doubt it will get fixed.
I went into the DA and dove a 190D and the propeller does not hold its RPM setting (Which is realistic..the wind will drive the prop at high speed) but the fuel flow does not increase with RPM
It took me quite a while to get wrapped around what you were trying to say because I was doing all the testing in level flight and everything was working like it is supposed to. It was only when diving that the issue becomes obvious. RPM increases above setting but fuel flow does not (and it should increase).
I'll write it up in the bug forum but it shouldn't be a high priority to get fixed as it affects very little. You shouldn't be diving with the prop back very often.
Thanks Dawger! :cheers:
I'm glad to see at least one other person sees something that seems to raise an eyebrow. I'm not too worried about it getting fixed, honestly. This game isn't really about cross country flight planning, and calculating fuel burns.
:salute
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Sorry it took me so long to figure out what you were trying to say.