Bob Pham

I bought someone's handiwork of a heavy 9lb Aeromaster II, super nice job, at a local hobby shop. He had an OS 90 4stroke in it. I installed a brand new Fox Eagle III in it. I took off and made one circuit and the engine quit. The plane started to spiral to the left (port side) and continued almost in a wingtip to wingtip spiral in about a 45d attitud and would not come out of it. It is very repairable. I have heard of this being a 'trait' with Lou Andrew's design. The plane has been sitting in my workshop and I want to fly it again. I have broken in the Fox since then. Thank you in advance for any input.

BentBalsa

My Feedback: (9)

Would like to find out myself I have not built mine yet
Thanks
JR

Rodney

I've had seven of these, the old Andrews kits, and all flew very well. I did have to make some minor adjustments on the incidence angle of the top wing on three of them to make them really great fliers but none have evidenced the trait you mention. In fact, they flew more like gentle trainers when you cut back on the throttle. I now have the Giant Aeromaster nearly ready to fly, need to mount the engine and paint it yet.

BentBalsa

My Feedback: (9)

Rodney

What did you do to correct the problem you mentioned.
Maybe I should do the same when I finish building.

Thanks
JR

I did have to make some minor adjustments on the incidence angle of the top wing on three of them to make them really great fliers but none have evidenced the trait you mention

Mike James

It sounds to me like the plane had some trim problems, which are compensated for by thrust. When the thrust s gone, so is the trim fix.

If it were me, I'd do all the obvious "modeler stuff":

> Check the basic alignment of everything, including the firewall.
> Check the incidence of the wing and stabilizer.
> Check that the vertical fin is attached straight, not at an angle.
> Check for warps.
> Check control surfaces for alignment at neutral, and their throws.
> Check the CG.
> Make sure there's nothing loose on or in the plane, that can move around in flight.

That's at least a good start on diagnosing the problem.

Champ-RCU

My Feedback: (132)

Bob, Let me ask you one question. As the plane was spiraling in, did you hold full up elevator in an attempt to pull it out from the spiral?
If you did, you did what's known as the death spiral. You stalled the airplane and put it into a deeper stall as you pulled more up elevator. The fix for that is less angle of attack by less up elev. or even some down elev. untill flying speed is regained. Then land as normal. Mark

PS If you didn't hold full up elev. then I have no #$%# Idea what the problem was. Good Luck !