autotecart

Waw many thank kap for taking the time to do that for me my problem is now solved thank u very much

what is the advantage of going for the bigger wheel and different strut? Would the 3 1/4 sized wheel look too small?

radfordc

My Feedback: (14)

The bigger wheels work better if you fly off of grass. If you fly from smooth pavement (or very well manicured grass) the smaller wheels look and work fine. The main thing is to get the wheels as far forward as practical. You might even need to put a couple of shim washers under the rear of the retracts.

Chris Nicastro

My Feedback: (3)

My buddy just bought one and I'll be flying it as well. This one was built with a DLE 20 and I've seen it fly before with the previous owner and it's quick.
I did notice the gear and stance are not quit right in stock form. Shimming the back edge of the retract just a millimeter will move the axle forward of the leading edge of the wing and reduce or eliminate nose over landings.
For a quick reference take a look at a P-51 in side view and you will see how far fwd the wheel axle is when it's taking off or parked.
Another trick that works great for me is about 1-1.5deg of toe out on the wheels. Helps tracking and calms awkward landings.

KaP2011

My Feedback: (17)

I've had another landing mishap, a fellow pilot where I fly tells me that I do what he calls "Space Shuttle Landings". Fast and to the point. I've gotten a little gun shy with tip stalls on landing warbirds. Same thing with my Ju 87 Stuka.

The problem with the Stuka I believe was that the landing gear had no flex to in. All landing forces were transmitted straight into the wing causing structural failure. My solution for the Stuka was to fit a pair of modified struts. They work very well.

When I inspected the damage to the P-51 wing I realized that the same thing was happening here. It was cold the day of my last flight of the Mustang and it looked like the glue joints had snapped loose. I remember the stock wires bending in the past. The wire is very stiff and I had to remove the retract to straighten the wire.

That being said, I believe the solution to the problem I'm having is shock absorbing struts. Oh well, back to the hangar for repairs.

flycatch

My Feedback: (26)

Time for you to use the flaps and throttle management.

KaP2011

My Feedback: (17)

LOL, yeah I've been told that. In the photo above the flaps were deployed but only at half flap. I've seen several Mustangs tip stall on landing with full flap so it spooks me a little. My Cessna 182 is another plane that I do the space shuttle landing with. I've lost several planes due to tip stall. My P-40 was the one that hurt the most and probably did the most damage to my confidence, it was lost on it's second flight.
The Stuka actually lands pretty good with full flap.

KaP2011

My Feedback: (17)

The flaps do work.

Chris Nicastro

My Feedback: (3)

Yes zooming your landings is not the best method. Power and flaps and a more positive angle of attack at touch down. Also carry a little power even as the tires touch because the initial drag will pitch the nose down sometimes. You have to fly them to the ground then ease off.
Try flying a few tanks worth of touch and go's and you will get the nack.

acdii

Mine doesnt have tip stall problems, it has flip over on its back and dive problems if you give too much up elevator at 1/2 throttle or more. I have not flown it slow enough for a tip stall except on landing, and the 3 that I did were perfect. Hopefully I can figure out what causes it and eliminate that issue. The last flight I had a very strong cross wind and not knowing to bank into the wind caused me too many go arounds and the last go around I went WOT, then instead of just turning it away I pulled up too fast, and over it went, two more feet of altitude would have saved it.

I have had the same exact thing happen up high going at 3/4 throttle, pulled up and it flipped over and was a handful to get back straight and level. I dont know if its the elevators, they have a slight twist to them.

Mine also pitches on its nose when taxing. I really should put some Robart struts on it as the wire struts bend way to easy.

KaP2011

My Feedback: (17)

Sounds like a high speed stall. I had a super sporster that would do the same thing. Taking out some of the elevator throw solved the problem.

acdii

Thats what I have been told, high speed stall, there isnt much elevator to begin with. I still think the twist isn't helping any. When set to neutral, with the left one even with the stab, the balance tab on the right one sticks up a bit.

radfordc

My Feedback: (14)

You have too much elevator throw! Reduce the total amount of throw and add some exponential and you will tame that beast.

acdii

I will have to measure it again, I reduced it down to 3/8ths when I first encountered it, but didn't help. I will dial in more expo too(might have gone the wrong way).

radfordc

My Feedback: (14)

The reason a high speed stall or tip stall occurs is that the wing exceeds its critical angle of attack. The elevator controls angle of attack. Less elevator throw prevents excessive AoA. You should also check the CG. An aft CG aggravates the problem.

KaP2011

My Feedback: (17)

3/8 is the low rate setting for the elevator. If your using a Futaba radio system the expo should be a negative setting. radfordc may be right about the c/g being a little off.

Flying Fiz

So guys, I'm about to start my build and with all the talk about retracts being ripped out and nose overs etc, I was thinking of keeping it lighter than heavier.

Two questions,
1. As I have a new 15cc and a new 20cc engine would the 15cc be enough to have some spirited flying, and assuming it is,
2. Will it need some extra weight up the front to balance correctly if I go with the 15cc thus defeating the reason of making it lighter. Better to just go with the 20cc straight up?

I'm would like to go with the 20cc.

Thanks,
Phil

j301

My Feedback: (12)

I know a guy that uses a 15cc in a CMP Hellcat and it does ok, and I believe that's a tad bigger and heavier then the TF P51. It depends on the 15 you have I guess, but I wouldn't think you would need to add any weight, just move your batteries FWD. Perhaps the decrease in wt and its more "slippery" design will make it a "spirited" plane, likely beyond scale for sure. I would give it a try, the worst thing that could happen is that you find its not enough and plunk in the 20 anyway, just don't over estimate what a 20cc will do for you, wont be one of those climb like a 3D profile or scream like a hot-liner planes even with the 20, but spirited yes.

As far as the tip stall, fast landing fear, the flight I lost mine on (when the motor went to its cycle of dropping to about 1/4 power, almost die, 1/4 power, etc, etc) I was in a cross wind and ended up nursing it all the way around and almost had it landed under full rudder with ail. cross control flying surprisingly slow for a P51 before it snapped and went in. (could have just been that bad juju of waiting until I was over asphalt to make sure it got good and crunched!) That was with gear down and flaps as well. Im not suggesting landing it like a floaty sport plane or stick for sure, but it does handle quit nicely for a warbird.

Flying Fiz

Thanks for your comments, I'll think about it a bit more and check the weight difference. The 15cc also has the benefit of just being run in whereas the 20cc is NIB. The 15 is an Evolution whereas the 20cc is an OS GT22.

I had the 15cc in a 65" Seafury and it really hauled so I figure that should be the same for this P51 because whilst its a bit slicker through the air i think its heavier, so should equal out then I could save the OS 22 for the upcoming H9 20cc Corsair.

It may even come down to fitment as the standard exhaust on the 20cc may not fit, It may require a slim wrap around.

Thanks,

Phil

Duplicator41

My Feedback: (1)

IMO a 20cc is too much engine for this model. It was designed for a .61 two stroke or .91 four stroke. All the ones that I've seen that have problems are usually overpowered and the guys flying don't fully understand the use of the rudder not only on take of but well into the climb to altitude. I'd stick with the 15 cc. Heavy also contributes to ripped out gear, nose overs and ground loops.

Cheers,

KaP2011

My Feedback: (17)

+1

acdii

Flies perfectly with a Saito 100 on it. Just the right amount of power for scale like flying.

chorner

Hey guys...

Just a note to those using or planning to use the eFlite retracts. Instead of drilling or removing the plastic tubes just pop the plug off of the retract wire leads, and snake the wires down through the tubes and re-attach the plug once through and into the wing. That's what I've done, and no cutting or drilling required.

radfordc

My Feedback: (14)

I won't say that the 15cc engine is not a good choice, since I haven't tried it. But, in my opinion, after flying this model with a 20cc engine, I think it is an ideal size for this plane and not overpowered at all.

The difference in weight between the Evo 15 and the OS 22 is 4 oz. On a plane that weighs 10 lbs, that amounts to a 2.5% increase.

The engine I used was the Valley View 20 which weighs 1 oz more than the Evo 15.

I don't think the choice between a 15 and a 20 can be made based just on weight.

chorner

I've personally had this plane rip out the retracts using both a 15cc and 20cc motor. One being an OS FS110a, the other an FS-120 III pumped. With the heavier FS120, it definitely wants to nose over all the time so you really need to get some angle on the retracts. Also, because of the small size of the wheels on rough terrain "good luck". The retracts and wheel wells on this plane were poorly designed in that regard even when running a smaller engine.

For me, I found the plane performed beautifully with the FS-120 III pumped and sounded great. With the lighter engine up front I found it needed more more trim (and I know you're thinking that is a balance issue), but with the overall added weight plus a little more forward balance it really solidified the plane in the air plus the FS-120III pumped just sounds great. If it wasn't for the really poor retract design I'd love this plane... but even with beefing it up it still has the issue of that ~5 degree angle needed to install some proper retracts with struts and needed to give a good tilt forward on the gear plus a smoother runway.

Looks cool in the air though and people love it at the field

Flying Fiz

For the first time ever I took it all out of the box to eyeball it lastnight.

Immediate observations;
1. It needs a good iron
2. Given its weight and size the 15cc should be a perfect match and I'll save my 20cc (which on checking last night is an Evolution not OS) for thenew H9 Corsair.
3. The retract support timbers and the overall structure is the weakest looking for this size plane I have ever seen by a huge margin....no wonder they rip out. I intend to do quite a reinforcement job on them including additional ply under the existing timbers and expoxying everything in the area. I'll also shim the retracts for more forward rake.
4. Hardware looks "old school" and I can't believe I need to solder some control rods/clevises.
5. Completion level not as good as most competitors. I know, I know its an old model, but they could have updated it in all these years and come out with a V2 or V3

I just built a similar sized Pheonix Seafury and a Seagull P47 Razorback and both were way better by way of build quality, hardware and things like the aileron and Flap servos mounting wooden blocks were already installed for you, the cockpit was completed together with realistic dashboard and pilot figure in place and more little things like that were a real nice touch.

Initial impressions with the TF Mustang are ones of real disappointment and that I have paid WAAAYYY too much for this model as it was exactly twice the price of the Phoenix and Seagull and only half as good. It cost me $500 and the other two kits were $250 and $280 respectively. I'm in Australia remember.

It better fly like a gem and look good as a finished product, otherwise I'll feel majorly ripped off!