Fuel consumption
 

I'm new to flying glow planes and currently in the process of getting my first one going. Its the GP Matt Chapman CAP 580 .46. I plan on putting an O.S.55ax and i have a 9oz fuel tank. What kind of flight time am i looking at for that setup. I love aerobatics so i'm usually balls to the wall http://www.rcuniverse.com/forum/js/f...sn/biggrin.gif. Lets just say worst case scenario running the entire tank at 3/4 to WOT. Thanks in advance for any help!

RE: Fuel consumption
 

Figure about one ounce per minute. The .55 isn't very bad on fuel though so you may do better. ABs aren't done at full throttle anyway. Throttle control is something that comes with time!!;)

RE: Fuel consumption
 

thats true but i noticed flying my electric 3D plane i like doing full speed fly-bys and vertical climbs. but of course that plane has a fraction of the power that my new one will. u almost have to be full throttle on the electric to have any power. ive never flown a nitro plane so i dont know if they are generally more powerful than electrics. i realize it depends on motor/engine size and all that good stuff though. i also only use the Tx that came with the electric plane so i was also trying to figure out how long i should set the flight timer on my new Tx for low fuel warning and so on

RE: Fuel consumption
 

Yeah, we normally train pilots to use the throttle as a slide bar and not as an on-off switch.

If you really want to fly good aerobatics and get reasonable flight duration, try this:

Take off at full, reduce to slightly over half, trim it out.. no roll no climb or descend, just straight and level flight with "hands-off" the transmitter. Emphasize - it should fly straight and level.

The trim should be set for that type of flight. Then aerobatic maneuvers returning to that throttle setting. You should easily exceed 10 minutes full tank of fuel with that OS 55 AX.

CGr.

RE: Fuel consumption
 

As Gray Beard says, "learn throttle control"!!!!! ;)</p>

Wide open with a .55 AX and a 9 oz tank you'll get about 7-10 minutes of flight depending on how you tune the engine.</p>

Ken</p>

RE: Fuel consumption
 

Hey Ken.. Stress test went well. See you in FL!!

CGr.

RE: Fuel consumption
 

Cool!!!!!! See you there!!!!

Ken

RE: Fuel consumption
 

I have a 55ax on a mojo 40 and I set my timer to 15 minutes. Of course that's kinda slow, flip-flop, dangling around flying for me though. Also good props for the 55 are xoar 13x4, apc 13x4 sport

RE: Fuel consumption
 

I train new students to think of flying a plane like driving a car. When your about to go up a hill in your car you don't floor it, you just roll on the throttle to maintain the same speed as needed. Most maneuvers, not all, are started from about half throttle and the power is rolled on to maintain that speed. Throttle is cut on the down line or wings tend to let go as you pull out. Some of the fastest planes I see out at the field are electric powered deltas, they can handle the stress better then a normal wing type of plane. I learned the hard way about too much speed in a big plane doing high G maneuvers.

RE: Fuel consumption
 

Ahem, that is pylon racing.

Since much acro involves the use of the rudder, speed control is critical. The rudder is most effective when the aircraft is slooooow.

12 to 14 minutes.

RE: Fuel consumption
 

ok i can see the point yall r trying to make. my electric is a little underpowered so when i say WOT its not like its fast speed. probably half throttle on my CAP would equal WOT on the electric. if i was wide open on the cap flying straight and level then pulled full up elevator at top speed it would probably rip the wings off...but not on my electric. i could input any control combo at full speed and it would hold up the the G's. i like seeing how crazy i can make it tumble and flip...but im sure the CAP wont be done the same. of course its always fun to do low high-speed fly by's in knife edge at WOT but apparently u dont need it wide open doing normal aerobatics.

RE: Fuel consumption
 

depends on the prop, plane, and how heavy you are on the throttle
ive flown a gms .47 for 50 min before on an 8oz tank....was just putting around the sky

RE: Fuel consumption
 

This is going to depend largely on the state of tune of the engine i.e. the fuel airmix and the, the percentage Methanol and Nitro in the fuel, and the prop load (incl Drag, wingloading and prop load)

On the ground with a 11x prop I get around 1min per ounce for a OS 46AX at WOT. All things being equal I'd scale that by a factor of the difference in the displacement of the two engines. and you'll have a very general figure to work with.

RE: Fuel consumption
 

One thing that I do, that many others do, is time the engine fuel consumption under the worse possible conditions. Actually, I don't do it specifically to determine how long the fuel will last, but to watch so that I don't get to lean while breaking in a new engine.

So, on a test stand, and a full 12 ounce tank, I set things up, start the engine, then, following break-in procedures, run the engine blubbery rich for three minutes, lean it out for about 20 seconds, then go back to blubbery rich for another three minutes. This goes on until the tank is approaching empty, you can see it when the bubbles form in the fuel line. I time it, for no better reason than because I do, and then I know how long the tank will last, under these conditions.. very rich AND at full throttle... but on the ground.

I then wait about a half hour then repeat the process. Each time, seeing if the time elapsed for each tank is about the same. But, by the time I reach the third tank, the rich, blubbery part, is down to only about 30 seconds and the lean max RPM part (within limits.. not to lean, but lean to get good two-cycle operation and good RPM) for the remainder of the tank.

When I fly, I sort of keep in mind how long the tank lasted during the extreme conditions of max rich and max throttle and go from there. So, I don't run out of fuel, but land it before it ever reaches that point.

Some pilots do this, some do not. Recommended? I don't know. It becomes part of my routine for a new engine, so that's the way I do it. And, it sort of gives me a gauge as to how long to expect a tank of fuel to last and I fly accordingly.

CGr.