Paladin,

I agree, mine is a unusual situation. This is the only warbird that I have had that I have not had to mix in down elevator. Also, it depends on your airspeed when you deploy your flaps. Thanks
Greg

Mine does not change pitch much but it really slows down. be prepared to add a fair amount of power to keep the airspeed up.

JLLAYTON

You're right, it's like putting on the brakes, I have mine set in two stages (15% & 30%) so it doesn't slow down so abruptly. The flaps sure make landings nice and steady though.
Greg

Scalecraft: I know that all the instructions show balancing while inverted but I have yet to get a reason from any source.

Nony: The "Up Ailerons" trick sounds like a great idea because you can remove the deflection as you become more comfortable with the plane.

Greg: Why all the weight in the nose? Please include your engine weight...I'm using the OS 1.20 Surpass III at 32.5 oz.

My thanks to you all.

Fred

Fred,

The reason for the nose weight is because I put in a full cockpit and had to move the servos for the tail rearward. Also it is not unusual for warbirds to require nose weight. Just think how much those massive engines that are in the full size airplanes weigh. I don't have the exact weight of the OS 91FX but I'm sure it is lighter than the 120 four stroke. The reason you balance upside down is so the plane doesn't fall off the balancer. Low wing planes balance upside down & high wing planes balance right side up. This keeps the bulk of the weight below the point at which the plane is supported. Greg

Greg, I agree about the smooth landings. I use about 40 degrees of flap, keep a fair amount of power on and fly it right to the runway. If you are patient you can absolutely "grease" it on. I also agree that with full flaps it feels like it wants to come to a dead stop.
Don't ask me how I know, but it will tip stall if you get it really slow, even with full flaps. I probably should confine my control to rudder if it gets a bit slow. Mine seems sluggish on aileron and very sensitive on rudder.
Jon L

Jon,

I won't ask how you know you know about the tip stall issue. I've been afraid to slow it down too much on landing to find out. I guess I'm chicken but I probably won't be trying three pointers with this one. Greg

P-40 guys,
I just started building a TF P-40 so I appreciate all the advice. I have been flying RC for 33 years, including a TF P-47, TF P-51, Global A-1 Skyraider and Global P-47. The two TF birds had flaps, the two Global did not. The TF P-47 was my first warbird,(overweight & tail heavy), and it bit the dust early due to gross pilot error. It turned/rolled left on take off and I tried to correct with aileron instead of rudder. BIG mistake. The P-51 weighs 11.5 pounds with a ST.75 and is slow on acceleration, but flys fine once in the air and cleaned up. No flaps along with slow airspeed equals an immediate & fast left roll of about 90 degrees. Full flaps and just a touch of right rudder keeps it tame as a ***** cat. Full flaps does cause just a slight pitch up. I sweat bullets through the first take off, then get it up high, slow down and try various configurations at slow speed to see how it reacts.
My TF P-40 will have an OS 91FX, Robart retracts with oleo struts, Bob Dively cockpit detail & flaps. I am debating about a retractable tail wheel, but hesitate to add that weight in the tail.

Darwin

Just a word of advice on experimenting with the stall on the P-40.
When you slow it down to the point of stall it will not warn you with a little buffetting in the wing it will snap violently and if you don't have a couple hundred feet before you get to terra firma you are going to loose your model. It's nice to know what it will do but when a heavy P-40 stops flying you have your hands full and you won't have time to think about what you need to do. A couple of hundred feet will evaporate very quickly with an out of control airplane. If you feel you have to try this make sure you have lots of altitude.

Jack Devine

Darwin,

I installed the retract tailwheel. If you do, there will be a weight penalty at the tail and as these tend to get tail heavy anyway, some weight in the nose may be inevitable. I originally had an OS 91 FS, but was tail heavy with retracts up, so I put a 120 FS in, and now OK. Identical options to yours too. If you do install the tail wheel, running the closed loop steering needs thought particuarlly if installing the cockpit. The servos need moving from the stock position and can get a bit cramped for running the tailwheel controls. They also need to be 'elasticated' since the length changes on retract, so that the wheel stays straight on retract. Even so, it can still bind if you're moving the rudder. I'd stick with the fixed wheel, and the pictures I've seen of P40 seem to indicate that the 'e' variant had both retractable and fixed.
Good luck

Robin,
Welcome back, mate! Please elucidate on the term "elasticate". I do not understand.

What's the source book for the fixed position tailwheel... this is new to me. Wait, all of this is new to me!

Oh, bother! Freddie's down in the channel again!

RedxFred,

Hmm, I suppose it was a bit cryptic. When the tailwheel retracts, the steering horns move up in a small arc, and the the length of the control cables changes... can't remember whether it becomes longer or shorter. As a result the cables become slack, and in order to keep the wheel aligned with it's wheel well, the control cables need to accommodate the change in length by using springs at some point along the linkage.

On the issue of retract or not, I may have been wrong. I've just looked through the references again, and none show non-retracting, but oddly I have in front of me a photograph of the Confederate Airforces P40-N in flight with the tail wheel down. I'll see if I can e-mail you the picture in a minute

On the reference, I used two Squadron/signal publications...
No. 8 Walk Around P-40 Warhawk ISBN 0-89747-361-2
Aircraft no. 26 Curtiss P40 in action ISBN 0-89747-025-7

I also have Flying Legends John M. Dibbs/Tony Holmes MBI Publishing CompanyISBN 0-7603-0563-3

Have a go anyway.

I think the point is clear concerning whether to mix elevator and flaps on the first flight then. Given the fact that there are variations in what is actually needed, some need it some don't, that it's better to first see how the plane reacts before adding mixing to the equation. Just imagine the angst if you've mixed down elevator only to find that what you thought would be a home sick angel has suddenly had it's wings clipped! Too much to worry with to take on that nonsense as well!!!

Happy landings!

Mark