I have a 44" w/span 450 sq.in. PH3D profile model powered with a GMS 47 with a APC 12x4 prop that weights 4.25 lbs and is a pretty nice flier. On the weekend our flying field grass was a bit too high for a take off run so I decided to do a first time hand launch of this particular model.

The model was launched head high at a fast forward trot at approx a 30 deg. angle. To my surprise the model lost a significant amount of altitude and ended up about two feet off the groung before flying on it's own. For all the flights we did the same thing happened every time even though the model was properly trimmed.

Doing hand launches are not new to me but this behaviour was and did give me some very anxious moments every time. The model has an excellent power to weight ratio and will literally fly out of one's hand if held vertical, so what could the problem be. Could it be the low pitch prop or what.

I would certaintly appreciate all and comments and suggestions.

Karol

Your foward trot was probably the problem. Just give it power and a slight toss up ( at your 30 degree angle) should be fine.

I like to toss downwind, at power enough to hover + a click or two. I hold the plane at the canopy area, and toss away from me at an almost vertical angle. Tossing into the wind is begging for stitches. Toss downwind.

I toss with my left hand, keeping the right hand on the right stick. If somehow, the plane comes at me, a push on the elevator, and it goes away again. Yes, I'm a neckstrap guy...

I do this on 5 ounce foamys up to 6 pound 100 size profiles.

And never look down. Keep your eye on the plane.

Thanks guys, never did a downwind launch, but will do so on my next outing wether the grass is cut or not. As they say "you live and you learn"

Karol

Remember, it's hovering, it's not flying. Launch into the wind, and head for the ER. Just a good toss almost vertical WITH the wind.

Been flying RC since 78 and have always launched into the wind. Guess I've been lucky so far and no need to tempt fate any further. With the wind launches from now on for sure.

Karol

I sent Toby Silhavy the designer of the PH3D profile model an e-mail outlining what was happening with my model, and he replied suggesting a couple things to checked.

It turned out that the elevators/ailerons were not at 0 degrees when at neutral. The ailerons had a couple degrees of up, which also explained why the model always needed a very long takeoff run before getting airborne.

Karol