We just test flew a scratch build a F117 NIghthawk form RCM plans, it took off fins and all seemed OK and then it pitched up into a nose high attitude and we could not get out of it , it wobbled all the way down and lucly for use only suffered a broken prop and rudders, can any one tell me WHY it happened and how can we gain control Mike

What kind and frequency of radio are you using? Did you inspect all the usual suspects like the flight pack batteries, servos, connections, etc and rule them out?

A brand new 2.4 Gig computer radio and everything appeared to be working, its a very complex control system, we had to phone a Tech to set it up Mike

It is rare but NOT impossible to be shot down due to radio interference on 2.4ghz. It has happened at the local fields in this area but the are considerably rare. If you have thoroughly inspected the control surfaces, linkage, load tested the battery, checked every servo wire for damage, and rang checked the radio, eliminating everything else, a radio shoot down is the only cause I can think of. I would still ask around at the field to see if any other incidents have been reported.

Could it have been tail heavy?

Bob

That was my thought also,I am currently building an Avro Arrow and the C/G really worries me, I have used a programs that shows me where it SHOULD be so I am hoping for the best Mike

well this may be a silly thing to say but depending on how scale this model is you may need to get used to a measureable amount of instability after all the fullscale uses multiple computors doing micro second calculations to keep it in the air.

I agree, I am just playing around with a big delta using elevons hoping to test fly it soon scary stuff Mike

The model is tail heavy.
Laddie.

Thanks Laddie, are you the gentleman who designs all those fantastic STOL planes with all the flappery Mike