mastic

Hey Fellas ,Ok I finish my Stangel Hummingbird kit ,put my Norvell 0.61 in it ,everything was looking good except I did not put on my rudder yet ,I never use one anyway ,so it was just missing about a 3/4 inch of balsa on the tail ,,So i crank it up to full throttle runnig nice and a buddy at the club tosses it for me and BOOM! it goes hard to right and down ..So i got some damage not much though..Question is why did this happen ?This is my first 1/2 A and I want to fix the problem before I fly it again ...Oh yeah I was using a 6x3 prop too .... Any Help Please??? and thanks alot

mclintock

My Feedback: (3)

Maybe that bit of tail matters after all, but the same thing happened to me when I thought the CG would be ok on my little quarter flash if it was just a quarter inch too far aft. Snap flip bam. So maybe you had the cg too far back, or the battery or something slid back and made the cg shift back. There was some proverb I read here that went something like 'Nose heavy planes fly poorly, tail heavy planes fly once'..
Was that one of those 'short kits'? Was it hard to build?

ptulmer

My Feedback: (5)

Sounds like your vertical stab was too small with the rudder missing. I've done alot of experimenting in this area. There is no formula for the fins on a delta, so it's fly-and-see. That's pretty much what will happen without the proper area in a vertical stab. I had one delta in the early stages that would fly straight until you went into the first turn and it would immediately flat spin. With a conventional layout a hard turn into the ground is likely. On another note... try a 5x3 on that .061 for more thrust. That's real handy with a hand launch. The norvel's need to rev to put out power.

mastic

Thanks fellas I will try all the advice

Scar

My Feedback: (3)

Before pointing fingers at the CG or the missing rudder.... how was that hand toss? I ask, because it sounds to me like it just snapped into the ground.

A handlaunch should set the plane on the air with the plane heading toward a point closer than the horizon. Nose down, gravity helps your plane gather speed. Nose up... gravity slows the plane, unless that .061 provides enough thrust to launch vertically.

Also, an application of elevator, before the plane has reached flying speed, will simply cause a stall (and the subsequent snaproll.) A proper hand launch will result in the plane headed away nose down, with both gravity and the prop giving it acceleration. When the plane has reached flying speed, a gentle application of elevator will help it fly level, where it can gain more speed. Finally, you'll have enough speed to make your gentle, climbing turn.

At least, that's what I think.
Good luck,
Dave Olson