I have recently built the World Models electric P-51. I installed an AXI 2808-20. I am a very experienced RC plane builder and built this plane exactly according to the instructions except for the belly pan. I didn't use the belly pan because the way that it mounts is "mickey mouse" and will not hold up if the wing is removed often. The CG is exactly correct.

The first flight was very scary. The plane flew very unstable. Extremely twitchy and overly responsive to the elevator and the roll rate is very slow. We checked the incidence and found that the the wing and the horizontal stabilizer were parallel. Everything I've been taught about airplane design says that there should be a 2 degree difference in the angle of the wing and the horizontal stabilizer. So, we intalled a couple of washers between the wing and the fuselage at the trailing edge of the wing.

The plane still performs poorly and "twitchy". It does not fly through the air "cleanly". Landings must be very hot or the plane stalls just before touchdown. In the air, when you back off the throttle, the plane slows down dramatically, not in a smooth transition like most planes.

World Models has a great reputation, but this model is really disappointing. Any ideas on what might be the problem?

this is mainly a radio setup issue. most recommended throws for warbird elevators are too big which results in twitchy elevator. so i would reduce your elevator throw and increase your aileron throw. if you have dual rates set your dual rate on the elevator to maybe 60%, and set your aileron throw to a higher amount, and keep adjusting these throws after you fly until you have the response you want.

for the throttle- this is more likely a function of the way your esc and motor work together instead of the plane. it also may depend to a small extent on the prop you are using. does your radio have a way to adjust the throttle response rate?

ed

Cant answer your "twich" problem but I can tell you this. I have one also and it flys great. BUT, you have to land this thing at a 3rd throttle. No control when you cut the throttle or go down to idle. Use throttle decrease to descend, and bump the throttle about 3 feet of the ground and it will land pretty nice. I have 9 planes from fomaies to a 27% Extra, and this thing is the hardest plane I own to land.

Thanks for your response. I've since figured out the problem. There are some long threads about this model. Apparently the instructions reference to the correct CG is off by as much as 15 mm. Almost all the contributors to the threads about this Model had to move the CG point a lot. For the manufacturer of the plane to be off by tbhis much is unacceptable. It is guaranteed that many crashed this plane on first flight because of tail-heavy instability! And you're right. It is damn hard to land !! You have to come in very hot!! Thanks again.