Republic XF-12 Rainbow

Sundog said:
Are you using the airliner version of the flying wing for it? It would be cool to see it with that cockpit from the airliner variant and the "glass" deck tail.

...Obviously the airliner version. I had in mind that the glass deck tail would be one of two meeting rooms. One inside that's shielded with no windows, the other one for more "diplomatic" missions where the President is showing off and using the grand wide view of the ground below and sky above to impress foreign dignitaries. ISTR there was a proposal to add such a large glass rear window on the current AF1 747 VIP deck, but nothing ever came of it.
Let's talk a little about true history, not "what if".
Anybody knows, where both prototypes equipped with photo lab or only the second?
I'll be heading up to the Cradle of Aviation museum later this month. I'm hoping to be able to get scans of some more Rainbow photos from their archive.
Dear zbrubaker
It will be very nice. It's always nice to add some pics/infos to collection.

Here is the picture from "Flying American Combat Aircraft: The Cold War":


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Here the pictures at the SDASM Archives.


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Well quite obviously, Republic revived the name a few of years later for a totally different airliner project. I also was shocked to discover that picture!
Hello friends!
Here are some more pictures, that i have find somewhere.
They are from Republic 16-mm film.


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Thanks Flying-Finn, those are definitely pictures I've never seen before. It's too bad the video isn't on YouTube.
Boy, am I ever glad that I found this forum! I have always considered the Rainbow to be the most beautiful aircraft ever flown, and I thought that I had seen all the published photos of it -- until this thread. Thank you all!
One more update on this topic! The beauty of the XF-12 is undoubted!


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Here's a little sumthin-sumthin on the Rainbow. It's an 8-page article, also suitable for either print or download

Courtesy of War Eagles Air Museum, out in my neck of the woods (more or less):
Let's try to keep here as much information about Rainbow as we can.

Here are two pictures from Le fana de l'Aviation:


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Has anything ever come to light about the the AP-60 bomber variant of the Rainbow, or the jet-powered follow-on variant?
XP67_Moonbat said:
Has anything ever come to light about the the AP-60 bomber variant of the Rainbow, or the jet-powered follow-on variant?

I haven't seen anything on this yet, but I'm sure one of our amazing researchers such as Mark, Scott or Jared will come up with something some day soon...

Do you know if the AP-60 bomber was meant for the Parasite/Missile carrier competition? Also, do you know if there was also a military transport version planned?
I don't. I'm reading my copy American Secret Projects and all it has a very general description.
As for the Rainbow being the fastest US piston-engine powered plane (with more than 1 mill)
-to go with the Republic claim of '500+mph' for its Thunderbolt prototypes..

..Just how does its actual test performance match-up with the competing Hughes machine?

Or the F7F & F-82?

That 'Betty Jo' Twin-Mustang record flight from Hawaii-to-NY was pretty impressive.
( I'd reckon those pilots would've failed a WADA banned substance test)..
Is there mention of the jet and bomber versions in this book "World's Fastest Multi-Engine Piston Aircraft: Republic's XR-12 Rainbow & the Hughes XF-11" by Mike Machat? One reviewer on Amazon seems to hint that there is...

'Worlds fastest'... that is a big claim..

Multi being more than one..

Or, even - if counting more than two,
just how fast was that Dornier high altitude triple-engined Do 217P prototype flown?
Under Mark Nankivil photos, what are numbers 208, 252, 253...? Picture number or Republic project reference numbers. I never see such numbers for Republic planes.
J.A.W. said:
'Worlds fastest'... that is a big claim..

That's not what was in J.A.W.'s post. He says Republic claimed it to be "the fastest US piston-engine powered plane" which is markedly different.
Actually S-G, they were both my posts, & I have doubts about both Republic based 'fastest' claims..
Barrington Bond said:
Is there mention of the jet and bomber versions in this book "World's Fastest Multi-Engine Piston Aircraft: Republic's XR-12 Rainbow & the Hughes XF-11" by Mike Machat? One reviewer on Amazon seems to hint that there is...


Not sure what the book mentions but there is a bit on jet powered variants in this thread;,561.0/nowap.html
All pics from "World's Fastest Multi-Engine Piston Aircraft: Republic's XR-12 Rainbow & the Hughes XF-11" by Mike Machat


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Excellent book by Mike Machat, with the added bonus of a lot of XF-11 info as well.
Found this model listed on eBay. Two engined Republic Rainbow? Was this an early proposal of the Republic Rainbow? Or different Republic project aircraft all together.


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The specifications for the RAINBOW/XF-11 competition were quite demanding.

The AAF demanded in 1943:

Service Ceiling: 50,000 to 60,000 ft.

Speed: 400 to 500 MPH at 40,000 ft.

Range: Sufficient fuel for 1000 miles at most economical cruising speed, plus 1000 miles at 400 mph at 40,000 feet, plus 1000 miles at most economical cruising speed, plus 25 per cent of the fuel required above as reserve. This fuel to be carried in self-sealing tanks. Provision shall be made for droppable tanks to increase the range given above. (This requirement is equivalent to a range of approximately 6000 miles at economical cruising speed.)

Special Design Note: It is desired that the airplane be designed to operate at 40,000 feet with one engine dead. This is another way of stating that the airplane must be a 4-engine aircraft.
50-60000 feet?

Makes you wonder what the **** kind of air defense threat they were thinking about.
Well, altitude is it's own defense.

The British, when they investigated the XB-32 Dominator mockup in 1940 or 1941 (forget which) made the comment that they desired a pressurized bomber with a 40 to 45,000 ft capability, as unpressurized fighters could get up to 25-35,000 ft range, but if you went to 40,000+ feet, you automatically forced a pressurized cabin onto fighters, thus inflicting virtual attrition on the defender.

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