Hand Launching?

Hand Launching?
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Hand Launching? - 7/20/2008 6:18:38 PM

Harvest Fields

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From: Dyfed, UNITED KINGDOM
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Hi all. Im a heli pilot and and just gotten into fixed wing. i have a futaba trainer 40. nice plane. probs are that the flying field is rather lumpy and not great for rolling take offs. i was wondering if ( and how ) to make a hand launch. is it a normal thing. is it oik? etc etc etc. any advice would be well appreciated .

Cheers all

Carl

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RE: Hand Launching? - 7/20/2008 7:26:22 PM

gregoryda

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From: Midwest SE, IN, USA
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I've done it in the past with a 25 size, so I don't think a 40 would not be any different other than the bulk and weight of the plane. I think it would be best to have someone else do the tossing while you are at the controls. Basically, all you do is bring engine to full power holding just a touch of up elevator, have the person launching it throw it straight out, not up or down. The plane will dip, recover, and start to climb. Just keep the wings level and feather the elevator to get the proper takeoff angle until you gain some speed and altitude before making your first turn. If it doesn't recover, the forward momentum/speed will cause it to glide safely to the turf without damage as long as the center of gravity on the plane is correct. If it is thrown upwards it may stall and drop a wing which means back to the workbench.

(in reply to Harvest Fields)

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RE: Hand Launching? - 7/20/2008 8:35:54 PM

im_a_rcav8r

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From: Palm Harbor, FL, USA
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The last poster is comparing apples with oranges. I have been flying for 15 year. I fly everything from .15 size to ¼ scale. A .25 size will hand launch without any trouble. A 40 is another story. I don’t know what plane your flying, however I think I would be safe to assume it has a 55-60 inch wing and is about 5-7 lbs. If your an experienced flyer and the person who is doing the hand launching is skilled you can do it. You have to be silky smooth on the controls and the person launching has to get a good fast walk forward and a nice FIRM but NOT hard throw into the wind. If the launch does not go well and the plane does not fly, it will return to the ground and at the least you will snap the prop. It is likely you will damage the nose gear and possibly the fire wall. In my opinion it is not worth the risk.

I recommend this.

I use to fly off a field with ruts, bumps and lumps every place. My plane would bounce all over the place. This is how I fixed that.

Be sure you have a good nose gear. Nice and stiff with a pull pull setup to the servo.

Next go to extra large wheels. I used the ultra light foam 4 inch wheels. The foam will help absorb some of the bumps and the larger diameter will role better over tall grass and bumps. The wheels that came with the plane are likely 2 or 2.5 inch rubber. They are nice for hard and smooth runways but not much good for a bumpy field.

You may try LXD766 Dubro Big Wheels 4” if you want to stay with rubber wheels, I have used them and they are ok, but a bit on the heavy side. That’s why I like the foamies.

Good luck!

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RE: Hand Launching? - 7/21/2008 5:04:41 AM

RCKen

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A 40 sized trainer is too big to hand launch. The hand launch is not going to give it enough air speed to start flying. So all you are going to do is watch the plane hit the ground and very likely injure yourself or whoever is trying to launch it. A plane of this size needs to be taken off from the ground on the landing gear.

Ken

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RE: Hand Launching? - 7/21/2008 5:15:38 AM

ply2win

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From: Orlando, FL, USA
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I agree that it's not a good idea to try this but if you have the right setup it does work. Just for the heck of it I tried it one time with a .40 size trainer that I wasn't very attached to and it just flew right out of my hand. As mentioned before, the key is to just give it a good toss straight ahead and then be real gentle on the controls. It also helps if you have an engine at the larger end of your plane's recommended range.

Even though it does work I would never consider doing it with a plane that I wanted to be sure and fly again.

(in reply to RCKen)

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RE: Hand Launching? - 7/21/2008 5:30:41 AM

combatpigg

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A couple of teenagers down the hill from me used to hand launch their Hobbico .40 trainers from a cow pasture all the time. Without the weight of the landing gear, that must have helped some.
With an intelligent choice of engine and prop [.45-.50 engine and 11x4 prop], the thrust should be plenty to launch a 6 pound trainer.
I have a "pasture-ized" Lanier Predator with a TT.40 and hand launches with that plane [with a 9x7 racing prop] are no sweat.
Why should a well made trainer be any harder to launch than that?

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RE: Hand Launching? - 7/21/2008 6:02:34 AM

OzMo

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HMMM lets see now

we have a greasy slippery plane
A propeller with tips moving the same speed as a .45 cal bullet
A guy who is new at airplanes
an aircraft that does NOT lend itself well to hand launching

all we need now is EMS on speed dial

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RE: Hand Launching? - 7/21/2008 6:06:28 AM

HighPlains

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Hand launching is really old school and not as difficult as people think. High wing airplanes that are slightly underpowered are easy even if you have to hold the transmitter in one hand and the airplane in the other. Just a slight amount of up trim, two or three steps into the wind, and a good heave forward and not upward.

Low wing airplanes are a bit more difficult, since they are difficult to hold with one hand. I did self launch one by turning it upside down and trimming it with down elevator trim for the launch. It was the first flight, and it flew up and away just like any high wing.

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RE: Hand Launching? - 7/21/2008 8:46:58 AM

perreback

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From: Sundom, FINLAND
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quote:

ORIGINAL: RCKen

A 40 sized trainer is too big to hand launch. The hand launch is not going to give it enough air speed to start flying.

I disagree. In fact, the manual for Kyosho's popular Calmato 40 trainer advises the pilot to hand launch the model into the wind. I've tried this on numerous occasions in the past, and it worked fine. The only problem is that the rapid acceleration during the launch will sometimes cause the engine to die. I'm not sure why this happens.

(in reply to RCKen)

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RE: Hand Launching? - 7/21/2008 12:48:28 PM

mclina

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If your runway is too bumpy for takeoffs, then it's probably too bumpy for landings. Even if you hand launch (I wouldn't do it), you'll end up damaging your plane trying to land. Between the "crash" landings and the occasional dead stick launch into the ground, your plane isn't going to last very long. You should probably find a better field to fly at.

Good luck

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Post #: 10

RE: Hand Launching? - 7/21/2008 9:31:20 PM

hogflyer

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Yes you can hand launch 40 size planes. I’ve done it quite a bit (I had one 40 size trainer that was a real squirrel on the ground and it was preferable to hand launch that plane), but there are several issues that need to be addressed:

* You need either a light wing loading or adequate power.
* The plane needs to have been previously flow and trimmed.
* The launcher is should not be the pilot upon launch.

It’s best if both people are pilots so they’ll understand what it happening during the launch, and it especially helps to have previous launch experience. Even 1/2A launch experience is better then nothing.

Hogflyer

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RE: Hand Launching? - 7/22/2008 12:03:30 AM

AstroDad

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we hand-launch my buddies Lanier Explorer 40 all the time.

basically his nose wheel keeps busting, so it will not roll on the ground, so we hand launch it. We hold it above our head heading into wind at full throttle. if it is gusty we wait for a big gust. the most important thing is to give it a clean launch even if it is not a powerfull launch. for the person on the controls the most important thing is not to pitch up too much and cause a stall.

(in reply to hogflyer)

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RE: Hand Launching? - 7/22/2008 5:34:16 AM

Charlie P.

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quote:

ORIGINAL: RCKen

A 40 sized trainer is too big to hand launch. The hand launch is not going to give it enough air speed to start flying. So all you are going to do is watch the plane hit the ground and very likely injure yourself or whoever is trying to launch it. A plane of this size needs to be taken off from the ground on the landing gear.

Ken

In the past I have hand-launched an RCM 40 trainer with a TT Pro-46 engine but it was not easy or recommended. Mostly a "can it be done" test with the model on skis and the snow wet and muddy spots of grass showing. OK, so it was "I drove this far and I'm going to fly today no matter what, darn it!" Worked well enough to get three flights that way without damaging model or assistant. It definately takes two; and your assiatant should not try to throw the model violently. Just a level push once you have full throttle and a bit of up elevator.

I could hand-launch my .40 size Hot Stik, but that is overpowered and will basicaly take off vertical if held nose up and released. Not a trainer by any stretch of the imagination.

< Message edited by Charlie P. -- 7/22/2008 5:36:24 AM >

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RE: Hand Launching? - 7/22/2008 1:41:23 PM

oceansfiftyseven

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We hand launched my Quest 50 while camping a few weeks ago. It worked very well but it takes a brave soul to do it!!!

(in reply to Charlie P.)