Composite Mustang 1/5 scale

[Chris Freeman 3]

This is a colaboration project, my son detailed a built mustang that I had purchassed and made a plug from it. A fellow modeller then made the moulds as he was interested in making a few kits to sell and raise some income as he is presently looking for work.

My involvement is funding and building the prototype. Strange how people think that when you work for a bank that you have money!

The first Mustang is being assembeled now and is needed to fly as soon as possible to check the design and construction. This is all a learning curve for all of us and has been a bit of a challenge so far. The overall weight will be heavier than the second one as it is hard to detirmine strentgh of a wing before completion. The parts that I received were not all the parts as the rudder and radiator scoop were not included and the plug for the canopy was also not completed yet.

Custom retracts are being made but not yet completed so the retracts from the original airframe will be used for now. We had no plans for the original so all formers and ribs had to be developed. I did all this the old school way with carboard templates.

[Chris Freeman 3]

The hard part when making a composite airframe is getting an idea of the strength that is needed for the components as the shape of the structure also can add strength. The wings were made with a heavy wood spar that supports the joiner tube and the retracts. a number of internal ribs were used but all this resulted in a rather heavy wing and stab.

I decided to have the Elevator and Rudder servos in the fuselage under the cockpit area to save weight in the tail. Pushrods are dowel with 4 40 metal clevises. Hinging is with Robart round hinges and the surfaces are shrouded in a scale manner but this also resulted in less movement on the Control surfaces. My son did most of the work on the wings and I did the rest.

The parts did not include a canopy, rudder, radiator scoop or any exhusts so these had to be made. The idea is to have this model flying as soon as possible so that we can see what it flies like and also make any changes required. A spinner also became an issue as no commercial spinners were available for this size of Mustang as it is larger than a Top Flight one but smaller than the CARF one. We found a Pica Spinner was a perfect match and managed to buy a part built kit that had a spinner and cockpit kit as well.

[Chris Freeman 3]

I managed to find an old Bud Nosen Mustang canopy that was used and my son arranged for the silver paint to be done at his work as as they paint full size aircraft, he also made the masks for the insignia to be used. Very nice masks, we sprayed all the colors in 5 hours and this was with 2k paint so it was pushing the limits as we wanted to attend our annual warbirds event with the mustang the following weekend!

[Chris Freeman 3]

More pictures

[Jon H]

Very nice. Do you know how heavy a production spec version would be? I guess around 20-22lbs?

If so i might be interested in one

[Chris Freeman 3]

This airframe is 89" so it is quite large, the weight of this one is 14kg, 31 pounds! I was very worried about the weight but remembered comments on my Spitfire light blog about weight of warbirds. At the warbird meet 2 weeks ago I watched an ESM Corsair flying with an 80cc motor and it also weighed 14kg so that gave me hope. We flew the Mustang last week and it flies very well, plenty of power and very good handling. No nasties at low speed.

Distance from South Africa is a problem so a few will be sold to the local moddelers I think but a am not involved in any commercial aspects, this is my hobby and I do it for an escape from bussiness.

[Jon H]

The logistics of getting from SA would make it a challenge.

I guess i will have to either buy the toprc version or build my Pica one. As i suspect im going to sell the pica kit (too many projects) i guess that leaves toprc when the time comes!

[Engine Doctor]

Hi John My Pica Mustang came out at 28 lbs AUW. Nice build but some of the ply parts are rubbish Its glassed and has a DL 50 cc for power . Now finished as " Passion Wagon" as flown by Capt Arval J Roberson 362nd FS Still un-flown ! four years after completion ! Eagle eyed may spot the fin extension not fitted to the original; apparently this was a field modification that stopped the P51 fish-tailing when accompanying bombers on long missions as pilots claimed it mad them sick ! It really need a four blade prop for static .

The composite job does look good

Edited By Engine Doctor on 26/06/2019 14:27:05

[Chris Freeman 3]

Thay looks great, I am sure that it will fly very well, our Mustang is the same size as it was based on a PICA airframe.

What retracts did you use, they look nice and sturdy. Not much elevator movement needed so set up the rates for the test flight as my son thought it was a little tail heavy until the low rates were selected. Much easier flying once this was done and landing was also on low rates. Due to the weight our CG is a little forward of the rocommended position.

[Engine Doctor]

Hi Chris . I'm not sure what make the retracts and oleos are as were supplied with a started kit that I bought years ago and had to re-do a lot of it !  They are air up spring down . I tried to keep the tail light and when I tested the CG it was way forward ! I have put a Sub c battery pack just rear of the wings to get proper balance although this may be changed to twin Life packs . I have 7/8 inch elevator throw on high rates and 5/8 on low as have found war-birds are very sensitive to too much elevator and the Mustang has a shortish moment so will be twitchy wit too much movement.

What flap deflection did you set up for landing ? Did you need to set any compensation for flap on the elevator ?

Pic is of the finished model with nose art taken at Rochester Airport at one of our Saturday evening fly-ins a couple of years ago .

Edited By Engine Doctor on 27/06/2019 11:05:12

Edited By Engine Doctor on 27/06/2019 11:06:26

[Chris Freeman 3]

Hi Engine Doctor

That looks great, it really does deserve to be flown. I also love the green grass, we only have brown grass and dust this time of year in Africa.

I am not sure how much movement we have on the flaps, I will check this weekend. My son said the Mustang lowered its nose when flaps and undercart were lowered. He said it was easy to counter with a little up and did not feel the need for any mixing to be added. I have this photo to show the amount of flap used on the lading and you can see how stable the approach was. Very surprising for an aircraft this weight.