Most of the planes I design & built are scale.
I build in foam using 5mm XPS sheet (laminate underlay) and as a stressed skin structure so the majority of the plane is basically hollow. In many cases this also means it can be rigid enough so little or no reinforcing is required. The end result is they are light.
My most comprehensive example of scale building was the development sequence undertaken by Hawker from the Sea Hawk to the Hunter via the P1052, P1091 and the prototype Hunter.
I started with a Sea Hawk

Not with the intention doing anything further but I was intrigued by the problem of a single 55mm EDF with wing root intakes and a bifurcated exhaust all squeezed within the chord of the wing root.
The substantial depth of the wing root meant the wing needed no reinforcement and relied entirely for strength on the foam skin.
The construction method allowed the complete duct and EDF to be assembled and the fuselage then built around it.

The inlet portion of the duct has a rather tortuous path which suggest the EDF would loose some thrust.
Despite this problem the Sea Hawk certainly flew well although near full power was required for much of the 3 minute flight. Its straight wings and benign flight characteristics certainly helped.
It was at this point I realised Hawker produced a swept wing version of the Sea Hawk the P1052.

It was a simple conversion retaining the same fuselage. With a second fuselage build I took the opportunity improve the inlet duct path at a limited expense of the exhaust duct.

With this layout the 55mm EDF certainly got closer to its "free air" thrust figure..
As the all up weight was the same improvement in performance was immediately apparent. It could now even achieve a belly slide take off yet only using an 1800mAh 3s!.
The next step Hawker undertook was to take the second P1052 and revise the rear fuselage to house a "straight through" duct with the exhaust at the tail. It was given the design number P1081

Like most of Hawker's prototypes it was finished in an overall pale green/blue. Simple to paint but a nightmare to see as a RC aircraft.
The inlet duct of the P1052 was retained but the exhaust duct was simpler and more efficient which was what Hawker had hoped for.

But it does show just how long the duct was with the turbo jet the sane position.
Rather as expected it too flew well. In real life the test pilot tried to exceed the speed of sound lost control, ejected but due to a mal function failed to separate from the seat and was killed.
By now it was obvious that the bulky centrifugal RR Nene turbojet was not suitable for super sonic flight so the next design was the Hunter using the more powerful axial compressor RR Avon.
To complete the development I had to build that as well but using a more power 12 blade 50 mm EDf,

As in the full size the EDF was further back in the fuselage allowing a further improvement to the inlet.

Built to the same scale as all the previous and in Hawker prototype colour flew very nicely although somewhat faster. but still retained the same 1800mAh 3s for comparison.
As a 12 year old my dad took me to the Farnborough 1958 air display where I saw the Black Arrows of 111 squadron loop 22 Hunter F6 together. A record that has not been beaten.
I just had to build an all black F6!

Some detail differences with extended drooped leading edges, under fuselage canisters to catch the Aden cannon cartridge cases and an airbrake it too flew well
All five "Hawkers" together.

I have never before built so many EDFs all to the same scale and over such a short (3 months) time period.
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