Full scale reproduction WWII fighter aircraft utilizing composite materials?

[Broncazonk]

I posted the following question on the Aerodynamic forum:

"Would it be possible to construct exact reproduction WWII aircraft out of composite materials? The structural weights would be much less, and the weight distribution would be dramatically different, and that would impact CG and wing placement, but could all that be worked out? [...]

The empty weight of a P-51 was 7,635 lbs (3,465 kg) and I'm wondering what would happen if 4,000 pounds was trimmed off an aircraft with the exact same lines."

The responses can be summed up as, "It's possible."

Okay, lets talk materials and manufacturing. The project would begin with 5 (five) exact, full-scale replicas of the P-51D. (Engine power will be provided by Allison V-1710 V-12s, not Merlin/Packard V-1650-7s (which would destroy the budget.)) The aircraft will be required too be fully aerobatic and structurally robust to survive a display/airshow/movie set environment.

If you were the project manager, how would you build them and out of what?

 

[berkshire]

Broncazonk (Materials)
(OP)
Ok now you have come up with a quantity, at 5 airframes you could just about pay for Fiberglass / epoxy tooling made from a plug of your aircraft, which could be made from dense foam cut on a CNC mill.
One thing you have to note is that Composite airframes are not always lighter than Sheet metal and in some cases are heavier.
B.E.

You are judged not by what you know, but by what you can do.

 

[Broncazonk]

I forgot to mention that the tooling (entire construction process) would (hopefully) be subject to continued production beyond the first five. The idea would be to sell follow up examples in kit form.

 

[berkshire]

Broncazonk
A few things to consider:
Whilst this is not quite the same thing, HP aircraft here is an example of an advanced composite aircraft manufactured from molds to be sold as a kit with the object of producing many aircraft from the same molds.
In your case more up front money will get you better tooling to produce a better product later, it does however delay the break even number.
One of the biggest pitfalls is taking an aircraft manufactured in one material and making it in another. The Lear fan was a good example of this , the aircraft was made from carbon fiber using methods and techniques better suited to aluminum fabrication rather than methods more suited to composite construction..
In your case you have a metal aircraft that you already have proven aerodynamic design you would like to make in composites. These materials have different natural frequencies and would most likely have different flutter characteristics. You would need a team of aero elasticity specialists, and structures people to go through the whole design. You also have the problem of loss of strength at elevated temperatures which may limit your choice of finishes on the aircraft or require you to use expensive autoclave methods.

You are judged not by what you know, but by what you can do.

 

[Broncazonk]

Berkshire raises an important point: the exterior dimensions, curves, outline, and shape of the aircraft is set and predetermined, (with the limited possible exception of the airfoil selection.) There can be no compromise on the exterior exactness of the reproduction, a "close, but not exact copy" would NOT be accepted by the public. (We are even exploring how to reproduce the distinctive sound of the Merlin's supercharger, and the subtle dimpling of sheet metal in the paint job.) So with the exterior design already set, who do we talk to first, an aero elasticity specialist, or a composites structure guy?

It's the inside that needs to be designed, not the outside.