A friend of mine recently built a Spacewalker and is having serious problmes with what I think are tip stalls. It flies great until he turns into his final apporach and decreases throttle. As soon as speed slacks off the left wing drops and the plane starts to nose over to the left. Is this classic tip stall or maybe something else?
Has he checked the lateral balance of the plane ? I had a World Models Chipmunk do this and it turned out the wing was heavy on one side. Just a thought...
CJ
Also check to make sure the CG isn't just a little too far back.
Check the wings for equal washout on both sides.. if it turns out that there isn't any put some in. All this assuming that he isn't really tail heavy. Also if it has "barn door" ailerons vs. strip ailerons he might need differential cranked in either electronic or mechanical.
Phil AMA609
Watchur6 wrote:
Does this happen while he is still turning? If so, was it a left turn? If it was, he probably skidded the airplane at low airspeed and it did exactly as designed: the inside wing stalled and it dropped. If it dropped in straight-ahead flight, he may have a trim problem, with the rudder trying to turn the airplane to the left and right aileron trying to counter the rudder's effect; get a little slow and it will stall the left wing first. The left wing might have too much incidence, or may have wash-in, or may have a rough top surface. In any case, it sounds like he's getting too slow on final.
Dan
I've had the same problem with an Aero Tiger... Get the plane up and trimmed so it's flying str and true.Get it down in one peice and raise both ailerons up two turns of the clevis.this cured mine.
I agree with Dan's comments that apply to this happening while making the turn. Even though I've flown enough years with enough different models, I let it happen to me on my slightly overweight Telemaster that I use for aerial photography. On turning left onto final, I'd neglected to keep the engine power up sufficiently until after straightening out on final, and two things happened. First the left wing dropped, and then the entire model dropped much too fast after rolling level and straight. Just quit flying essentially, and failed to even make it to the end of the runway, but fell into some high weeds and bushes. Luckily it was repairable, but another lesson relearned!!!
Olin McDaniel
Raising ailerons in this manner might help, but is nowhere near as effective as properly built in washout.
Whashout can be introduced after building by careful heating and twisting the wing in the appropriate direction - easier with built up wings than foam core.
If introduced in this way, constant monitoring is needed to ensure that the twist doesn't disappear over a period of time.
Malcolm
| A friend of mine recently built a Spacewalker and is having serious problmes | with what I think are tip stalls. It flies great until he turns into his | final apporach and decreases throttle. As soon as speed slacks off the left | wing drops and the plane starts to nose over to the left. Is this classic | tip stall or maybe something else?
Sounds like a tip stall. Sounds like the angle of attack on the left wing is just a bit higher, so it stalls first.
A tip stall is still a stall. And you stall because your air speed is too slow. (Well, it's more complicated than that -- it's really related to angle of attack, but that's good enough for now.)
Following the instructions given for increasing wash-out will help turn the tip stall into a normal stall which is usually less serious, but the ultimate answer is to not slow down so much.
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