Republic P-47, Pre-Projects, Prototypes & Projects

are these wind tunnel models? I see no carb and oil cooler inlets.
More than probably, Hesham's remarkable find represents
the early Republic AP-10 concepts for a lightweigt fighter
with a liquid cooled engine.
A full scale mock-up was later contructed.
Air intake for the carburettor via a scoop above in the
engine cowling.Later drawings showing cooling air intakes
in the wingroots.
AF asks
are these wind tunnel models? I see no carb and oil cooler inlets.
Hesham's link is to a report on wind-tunnel studies of carburettor air intakes
From the NASA CRgis site:,_Cooling_(Part_1)

Some remarkable images, including, apparently, an annular radiator installation.
Hesham, that's a great finding. XP-47A concepts, wow!!
Having looked the photos over, I'm struck by the comprehensiveness of the Republic/NACA investigation. They tried out every variation they could think of on radiator and carburetor scoops. Interestingly, for all the variants and refits, there seems to be photos in this set of the "A" type P-47 only. The "B" type is seen in one poorly-reproduced photo in the document that Hesham kicked this thread off with, so there was a mockup of it as well. I screengrabbed a photo from the PDF.

I suppose I should point out, just in case anyone's scratching their heads, that Republic's designation of these designs as "A" and "B" has nothing to do with the eventual P-47B Thunderbolt.


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Hesham's drawings are probably the initial Republic AP-10
designs which later bore the designation XP-47 and XP-47A
and of which only mockup's were constructed.
From wikipedia
In 1939, Republic Aviation designed the AP-4 demonstrator powered by a Pratt & Whitney R-1830 radial engine with a belly-mounted turbocharger. While the resulting P-43 Lancer was in limited production, Republic had been working on an improved P-44 Rocket with a more powerful engine, as well as on a fighter designated the AP-10. The latter was a lightweight aircraft powered by the Allison V-1710 liquid-cooled V-12 engine and armed with eight .50 in (12.7 mm) M2 Browning machine guns. The United States Army Air Corps (USAAC) backed the project and gave it the designation XP-47.
As the war in Europe escalated in spring 1940, Republic and the USAAC concluded that the XP-44 and the XP-47 were inferior to the German fighters. Republic unsuccessfully attempted to improve the design, proposing the XP-47A. Alexander Kartveli subsequently came up with an all-new and much larger fighter which was offered to the USAAC in June 1940. The Air Corps ordered a prototype in September, to be designated the XP-47B. The XP-47A, which had almost nothing in common with the new design, was abandoned.
Strange that on the 3 views shown by Hesham the
belly cooling airscoop of the mock up is not visible ..
lark said:
Strange that on the 3 views shown by Hesham the
belly cooling airscoop of the mock up is not visible ..
The absence of any obvious radiator scoop on the 3-views may indicate that Republic planned to select its final placement/configuration after empirical testing at Langley. As the photos indicate, they tried several intake and exhaust locations and shapes, including the belly scoop.


from the American Fighter since 1917,here is some Republic
P-47 variants.


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The XP-47.


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Clioman said:
Hesham, what's the source for these two pages?

Hi Clioman,

it's the book; Republic's P-47 Thunderbolt From Seversky to Victory
I´m trying to collect data to convert a 1/72 P-47D to P-47B to XP-47F.
A web search shows two drawings:
XP-47F wing.png
As you can see, there are substantial differences between the two drawings regarding wing planform and skin panels. Do you know which one is correct?
Lower one came from a russian site and has a longer chord in the wing root. Flaps and ailerons are substantially bigger, also.
Ok, got one for everyone. I've seen a picture of a P-47 with what was labled as a "supersonic" propeller. It was a four-blade setup with "scimitar" shaped blades similar but larger diameter than the later Un-Ducted Fan high speed blades. Anyone have information or links to such a thing?

The tips at least of these higher performance PE aircraft were supersonic anyway while the aircraft were not but it sounds like a race aircraft with modded prop.
Here's the only NACA report I could find on the XP-47F, but there's doubtlessly at least a couple more. The document provides a planview drawing of the aircraft, though rough. Additionally, here are some photos of the aircraft that I was able to find crawling around online, plus one photo I cut from the provided document.


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Thunderbolt evolution


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Thanks for sharing very rare images, Justo-san. Thunderbolt with sweep back wing and AP-47 are new for me!!:oops:
Has anyone more information on the P-47 "Double Twister"? An interesting contra-rotating prop design, though there seems to be only one known image of it. Sadly the vertical stabilizer is obscured so I can't confirm the tail number, but "15942" seems to check out based on what little I've gleamed from around the corners of the internet. Using Jeremy K.'s serial number search (, it gives a P-47B, though stated as having been written off in early 1944 at Clymer, PA.
This image seems to appear in Warren Bodie's 1995 "Republic's P-47 Thunderbolt: From Seversky to Victory" along with a little coverage of the type. I'm assuming that means it's copyrighted, and so sadly I can't post it here.
From, Русские крылья Америки. «Громовержцы» Северского и Картвели.


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From this book.


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I can't help but wonder if the contra-rotating p-47 "double twister" wasn't a missed opportunity. Certainly 2800hp is getting to be a lot for a single prop and the additional climb rate afforded by the "paddle prop" would seem to suggest that the greater swept area could only benefit the heavy Jug. At minimum it would have benefited the pilot workload when changing power settings, as I understand it the thunderbolt was a bit tedious to fly in that regard

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