ASJA L-13

[blockhaj]

The last aircraft designed by Swedish aircraft manufacturer "ASJA" (Svenska Järnvägsverkstädernas Aeroplanavdelning) before becomming "SAAB Linköping" was a fighter project, numbered L-13, in 1939. It was similar to the ASJA L-12 conventional single-seat fighter (later renamed SAAB 19), but featured a central mounted engine, contra-rotating twin-blade propellers and slightly larger dimensions etc. I believe inspiraton came from the Koolhoven F.K.55 which was displayed at aviation conventions at the end of the 1930s. Blueprints/linedrawings below via Tobias Holmbom on Facebook. Various books mentions that the L-13 was to have a radial engine, most likely the Bristol Taurus as per the contemporary L-12 project. A few books mentions a L-13 concept featuring twin-booms like the later SAAB 21. It is said that cooling problems with a central radial engine could not be solved practically and the project never went anywhere and was eventually replaced by the SAAB 21 projekt in March 1941. Since Britain would not sell the Taurus engine to Sweden either way, the project was effectively dead in 1940. Armament is shown as two machine gun looking weapons, one in each wing. These would most likely have been 13,2 mm FN Browning guns which Sweden adopted in 1939. While low in caliber, they fired high explosive tracer ammunition at a rate of fire of 1100 rounds per minute; very potent for the time.

 

[hesham]

From Sveska Flygplan

 

[Apophenia]

From Sveska Flygplan

Svenskt Flyghistoriskt Forum has already covered this repeated error:
-- https://forum.flyghistoria.org/viewtopic.php?t=22336

Några böcker nämner ett L-13-koncept med dubbla stjärtbommar som den senare SAAB 21, men detta verkar vara missförstånd då Frid Wänströms skiss för J 21 kom senare.

Machine Translation: "Some books mention an L-13 concept with twin tail booms like the later SAAB 21, but this seems to be confusion originating from the later release of Frid Wänström's sketch of the J 21."

So, no. The ASJA L 13 design featured neither a pusher engine nor twin-boom fuselage.

 

[Darcrner]

Interesting project, I did not realize the L 13 got that far with drawings and engine planning before being dropped. Do you know if any wind tunnel data or performance estimates survived, like projected speed or climb rate?

 

[blockhaj]

Interesting project, I did not realize the L 13 got that far with drawings and engine planning before being dropped. Do you know if any wind tunnel data or performance estimates survived, like projected speed or climb rate?

Probably, but i have not researched the subject.