Republic AP-9


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22 January 2006
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I'd like to know more about the Republic AP-9 which was Republic's entry at USAAC X-609 single engine (V-1710) high altitude pursuit requirement from March 1937. It was the rival design to Bell Model 3 and 4 that later developed into the P-39.

Anybody can post a drawing and tech specs.

Thanks in advance,

Search in 'Aero Album Vol 7' -Paul Matt- Aero Publ. Inc.1969
produced this info:

AP-9 Reportedly built from AP-8.This aircraft had a sharp downwardly flexed wing
leading edge and inward retracting landing gear.Powered by a Prat & Whitney R-1830S3C-G engine
of 850hp, it was tested on Wright Field in Febrauri-April 1939...

In the same article :...'an AP-8 may or may not existed.One report states that the AP-8
had a different landing gear and wing section from from the AP-2..

Strangely the Army competition is not mentioned.

So far the two part article: The Seversky Story.
Among the many contributors - Peter M.Bowers.
Powered by a Prat & Whitney R-1830S3C-G engine
of 850hp, it was tested on Wright Field in Febrauri-April 1939...

Enigmatic words. I understand that AP-9 was not a paper project from that text, it came too years later to X-609 competition and it was dramatically underpowered against contemporary fighter designs...
Well , it was a surprise to me also...
In the text is mentioned that in the early days of Republic it was
often so hat an existing airframe was altered or rebuilt to
fit in a new request and thus received a new AP-number.
(think there's still much work to do on the Ap-1-AP-100 series)
Mmm, the Republic's archive is lost forever. But if the AP-9 was tendered to an official competition some work in NARA ought to bring something about it.
This is on page 31 of "The Thunderfactory" By Josh.Stoff-Arms & Armour Press- Great Britain 1990

...the Seversky AP-9 was another entrant in the 1939 AirCorps Fighter
competition.Built from the never completed AP-8 , it featured an improved aerofoil and the now
standard flush landing gear.It was powered by a Pratt & Whitney R-1830 turning a three-bladed
Hamilton Standard propeller but had no supercharger. In spite of these improvements
the Air Corps turned down the AP-9 in favour of the Bell XP-39 and the Lockheed XP-38....

So far :Joshua Stoff.
The entry suggests that the AP-9 was essentially the same as AP-7 modified to AP-7A standard with flush retractable gear (pic below). Interestingly, Aerofiles also notes that the sole prototype was sold to the Dominican Republic in late 1940!

From another point of view, I think there were a number of very attractive small (or moderate) diameter radial engined fighters around 1940. I like the AP-9, the FW-190 V1 without the wierd spinner, the Zero, the P-66. Also the CW-21B. Chance Vought V 143. Good modelling projects.
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