Ww2 Biplane

[willedoo]

Came across this possibly lesser known WW2 fighter, the Kochyerigin DI-6 (ДИ-6). A two seater, it had an open pilot cockpit & a partially enclosed gunner's cockpit & retractable main gear. Production ran for a couple of years, 1937-1939 & it was apparently used as a fighter with ground attack capability. One interesting thing about it is the engine, a Shvetsov M25, which was a liscensed production variant of the B17 engine, the Wright Cyclone 9.The earlier ones were built from kits imported from the US; the later models differed from the R-1820 by the use of metric dimensions. The plane was supposed to have had quite a vibration problem.

 

Cheers, Willie.

 

[ATTACH=full]836[/ATTACH]

 

 

 

[Bubbleboy]

It has a real Polikarpov flavour to it!

 

Scotty

 

 

[siznaudin]

.... the later models differed from the R-1820 by the use of metrics dimensions. The plane was supposed to have had quite a vibration problem.

Never heard of the a/c : always always something to learn isn't there! - the engine comment brought to mind this from Herschel Smith's excellent "Aircraft Piston Engines"...

 

"...Curtiss-Wright had gone to about the limit for a nine with the G series R-1820 Cyclone.....though at some cost to the smoothness. DC3 buyers had the choice of Cyclone or Twin Wasp power, and it was said that pilots from American Airlines, which used the R-1820, could be identified by their tremor, which took several hours to go away after a long flight with a pair of Cyclones. A gross libel, undoubtedly."

 

 

[willedoo]

Never heard of the a/c : always always something to learn isn't there! - the engine comment brought to mind this from Herschel Smith's excellent "Aircraft Piston Engines"..."...Curtiss-Wright had gone to about the limit for a nine with the G series R-1820 Cyclone.....though at some cost to the smoothness. DC3 buyers had the choice of Cyclone or Twin Wasp power, and it was said that pilots from American Airlines, which used the R-1820, could be identified by their tremor, which took several hours to go away after a long flight with a pair of Cyclones. A gross libel, undoubtedly."

I guess going by that, the engine must have been a lot of the cause of vibration as opposed to the airframe design or mounts etc. I wonder how the other cyclones went in the vibration department, the 14 cyl twin cyclone & the duplex cyclone, 18 cylinder from memory. I've got an old original Wright Cyclone R-1820 overhaul manual & it's got some really interesting reading in it, a lot of good stuff in it. They say another problem with the Di-6 was a fairly poor arc of fire for the gunner.

 

Cheers, Willie.

 

 

[willedoo]

It has a real Polikarpov flavour to it!Scotty

Photos I've seen of the early war Polikarpov's cetainly look very similar & I think they used the same engine with a supercharger. Don't know if there was any connection between the two. I read somewhere that the Kochyerigin DI-6 was the first Soviet bi-plane with retractable gear, beating the Polikarpov there by a couple of years.

 

Cheers, Willie.