This may sound strange but after helping an older man get a plane to fly with an underpowered engine, I have been thinking of this as a challenge and want to give flying a larger plane with a small engine a try for myself.. We did everything possible to get that plane in the air and finally it flew. I found that the hardest part was getting it into the air and once you have altitude you can fly as normal, without stunts of course. My question to you is have you experienced this? I was thinking of getting a plane with plenty of lift and just trying to see how small of engine would fly it. For example, a 40 size trainer and maybe a 15 or 25 size engine. If you have experience lets hear about it.

Buzz, my first RC engine was an Enya .46MkII fourstroke, I put it on a Kombat .60 from the Airplane Factory. Everyone that saw it said, "that thing cannot possibly fly" well nobody told the plane and it flew just fine. It used about 100 feet of runway, and climbed out like an airliner. Good training for a newber.

I saw a Sig Kadet Senior with a .35 engine. It took forever to lift off but flew around pretty good after that. The guy even looped it after diving the plane.

At the field where I used to fly, there were several planes in the 80" wing size (Old late 30's free flight planes) that guys flew radio controlled with 45 thru 65 four stroke engines.

They would take off and climb out as high as they could see to control the plane. Then cut the engine back to idle and ease around until the plane got too low then they would go back up again. They'd fly around like that for a half hour or more.

Buzz,


It seems no one wants to learn to fly these days...

A Cessna 150/152 can climb at about 700 ft. per minute, at maximum effort and it does it with the nose barely over the horizon.

Most R/C trainers would climb straight up, lest be called 'under-powered'.


There is no reason one should not learn that a normal model must actually fly 'on the wing' and only 'a barn-door with an engine' (a typical profile 3-D plane...) should prop-hang.

Most .40 size trainers would take off in 40-50' of runway, if you put a 15-.19 engine up front.
They will also pull out pretty well, somewhat like a current airliner.

Dave, when was the last time you watched a modern airliner take-off from a noise sensitive area airport?

These monsters, at MTOW put their nose 30-40º up and climb out at 4,000-5,000 ft./min.
Many jet fighters couldn't do this, not too long ago.

I think most SIG planes as a rule recommend smaller engines than other mfts of same size. Keep in mind underpowered in grass can be no fun but on pavement it is less of an issue. One setup that surprised me was a SIG LT-40 with a .25 and large 4"foam tires from grass with ease.

No need to change engines. All you need to do is to adjust the throttle linkage so the engine will only go to 50% throttle and fly the airplane.

The experience will teach you a lot about flight.

Bill

Just strap a brick, or several pounds of lead onto the CG of the airplane, and you will have your challenge. It will be even more challenging than an underpowered airplane.

JettPilot

A friend had a a 6 ft wingspan glider with a TD 049 on the red tank mount on the nose. Hand launched, it climbed out at a reasonable angle and got up pretty high before running out of fuel. It had spoilers and he would land it right at his feet.

Virtually all of today's trainers will fly very well with a .25. The student would have less problem handling the plane with the smaller engine, in my opinion.

When I first started teaching RC flying back in 1971, I guess, just about everyone started with a 3-channel trainer. Sig Kadets, Goldberg Falcons and other trainers did not have ailerons then. People learned to fly on them very easily.

These days with people putting .46s in trainers with flat bottom wings, they fly so fast you need to put in a bunch of down trim to keep them from climbing. When you throttle back to land, the elevator takes over, causing the plane to dive or the pilot to hold back stick. In the early stages of learning, when a student corrects his ailerons, he tends to relax on the elevator causing the plane to pitch down and boink on the ground. This is the reason I recommend putting 2 popsickle sticks under the trailing edge of the wing.

For a .40 sized trainer, if you want a .40, I recommend the much maligned OS .40LA. Sure it's low power, but it is plenty for a trainer, it's easy to tune and it's very reliable. That's the reason they sell so many of them.

If you really want to slow down, try an old timer free flight. Nearly all of the 1930s free flight planes have been converted for RC. Here's the URL for Penn Valley Hobbies that sells the Quaker and Dalaire. A buddy and I have the small Quaker and it's very relaxing to sit back in a chair or recliner and soar around with the old timer.
[link=http://www.pennvalleyhobbycenter.com/]Penn Valley[/link]

I've got a Great Planes 1/4 scale cub (full span version) that tips the scales at 13lbs and it flies just fine on an HP .61 Gold Cup. Takes off, flies, and lands very scale. Never had any inclinaton that it was really underpowered.

Heh heh - when I saw the subject line of this thread, I had exactly the same mental picture as you, except the guy at our club had a TT .42GP in his with an MA 10x6 and the airframe had been repaired about a dozen times and was no doubt a pound or two overweight. It flew OK though, once it had finally detached itself from the mother earth...

There's a guy in our club flying a Senior Kadet w/ a tired FP .40 and it's fun to watch, especially when it's windy. Foreward speed in a good breeze must be about 5 mph

When I started, I bought a mostly built Falcon 56...(in 1974 )
The guy sheeted the stab. w/ 1/16 balsa and w/ the rubber bands / dowels holding the tail on, it required a lot of lead to balance.
One of the older guys took pity on me while I was saving $ to buy my onw "big" engine and let me borrow his Enya .19...

Learning to fly on a 5 1/2 lb. Falcon w/ a .19 is a fun and educational experience
It taught me the meaning of "energy management".

I was 14 and mowed a lot of lawns to get my own Enya .29 later that year, and that made a huge difference...

Buzz: Get a simulator. If you don't already have one. Then, you can put as small an engine as you want in the various models and fly them on the wing.

I learned to fly on a Telemaster 40 powered by an OS .25FSR, it flew very scale and I had a ball with it. It flew off grass and loose sand with ease, the trick was a set of those inflatable Trexler wheels.

Flying "on the wing" is great fun! It's definitely a more realistic looking flight. It also teaches you the basics of lift. (no sharp turns if you're close to the ground!) Proptop; I was glad to read about your experience with the Enya 19. I have a low timer that I didn't think was big enough for a 4 lb. plane I have. (until I read your post!) Ross

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An excellent idea, BillS and it saves money too.


Ed Cregger

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An excellent point.

I do that frequently on my sim, both smaller than usual and larger than usual engines.


Ed Cregger

Jim,

You forgot to mention that those guys flying the '30s style free flight planes kick back in lawn chairs while they float way up there.

I learned on a Sig Kadet Senior powered by a TT Gp 42. It would loop and I could hold inverted but it was a challenge. Always did anthing like that at altitude. Still have the plane and it's intact and still flyable. I should get it out again next spring. It was fun.

Just dropped the engine size in my 80" Kadet Sr. from a Saito 72 back to a Saito 56 4-stroke. I believe the power to be ideal for this plane and it will carry it on floats equally well. As a matter of fact I believe the AMA promotional CD has this combination in it on floats. I have no doubt a smaller engine will pull this plane around the sky easily.

I agree will bill limit your throttle. I have a ball with my Sig SR , our club has 400ft sod grass runway and a 350 ft paved I love to long ROLL takeoff and see how LOW of a throttle it will take and still get lift off. It takes 200 ft or so at only 4 clicks above idle on a 72 satio 4c, this long an slow throttle take offs and landings have really help all my over all flying on all my planes, theirs nothing like SMOOOOOOTH..............when your in the mood........

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I would fall asleep. <G>


Ed Cregger