Yak-9U optical difference to the Yak-3

[alex33]

Hello,

I was just reading up on the Yak-9 on the loo so I read through the Wikipedia Article of the Yak-9 and I noticed an interessting line about the Yak-9U:

Visually differed from Yak-3 only by main landing gear covers.

I'm pretty sure the Yak-3 and the Yak-9 look quite different form another but this quote (without a cited source ofc) made me doubt my knowledge on Yak fighters a bit,

Isn't the Yak-9U based on the Yak-9T, and thus has its cockpit moved 400mm backwards? I'm also pretty sure, that the front part of the windscreen on the 3 is a single piece while the 9U's has a framing like the normal Yak-9. I sadly could not find a source on the cockpit possition but I'm sure it was put 400mm back same as with the Yak-9t, does anybody know anything about this?

Any help would be appreciated!

Best wishes
Alex

 

[Wurger]

The Yak-9U was a plane based on the Yak 9 generally , basicly it was designed using the Yak-9T. So it can be said that the kite "inherited" the main shape of the Yak 9 series. However there were technical/aerodynamical solutions used for Yak 3 adopted. Eg.. the transition between the fuselage and the wings, the main radiator was installed in the centerwing like it was done for Yak 3. Also the armoured seat back and the armoured glass behind the pilots seat. Additionallt the control system of tail wheel setting. Because of the radiator mounted in the centerwing , the 9U lost the air intake under the nose of the fuselage. And this made the plane appearance a little bit similar to the Yak-3.

Regarding the moving back of the cockpit .. all russian books about Yak-9T state that. Here you are a couple of shots of the Yak-9U and one of the Yak-3. IMHO it looks like the cockpit was repositioned back.

Yak-9U ..

Yak-3 ..

The pic source: the Internet.

 

[Wurger]

I know it may be not enough proof that the cockpit was moved back . So I have made an experimant and I merged three shots .The first one shows the Yak-9U armed with B-20 cannon ( red tone ) put on the shot of Yak-9D (B&W tone). The second one presents the same pic of Yak -9D but there was added the image of the Yak-9U armed with N-37 cannon ( red tone ). All pictures presented Yaks in almost the same position and weren't edited but just clipped and gave the same size. The only exception was the shot with the 9U with the standard B-20 cannon. I have had to slightly rotated it up in order to keep the correct side datum of both planes. As you may noticed, in both cases the 9U has the cockpit canopy repositioned back comparing to the 9D one. The difference is the length of the windscreen at its root. IMHO that's just the 40cm ( 400mm).

Yak-9D ...

Yak-9D and Yak-9U with B-20 cannon

Yak-9D and Yak-9U with the N-37 cannon

 

[alex33]

I know it may be not enough proof that the cockpit was moved back . So I have made an experimant and I merged three shots .The first one shows the Yak-9U armed with B-20 cannon ( red tone ) put on the shot of Yak-9D (B&W tone). The second one presents the same pic of Yak -9D but there was added the image of the Yak-9U armed with N-37 cannon ( red tone ). All pictures presented Yaks in almost the same position and weren't edited but just clipped and gave the same size. The only exception was the shot with the 9U with the standard B-20 cannon. I have had to slightly rotated it up in order to keep the correct side datum of both planes. As you may noticed, in both cases the 9U has the cockpit canopy repositioned back comparing to the 9D one. The difference is the length of the windscreen at its root. IMHO that's just the 40cm ( 400mm).

Yak-9D ...
View attachment 574990

Yak-9D and Yak-9U with B-20 cannon
View attachment 574991

Yak-9D and Yak-9U with the N-37 cannon
View attachment 574992

Absolutley great! Thanks!

it can also be quite clearly seen that the cockpit was put back 40cm in paintings from the yefim gordon books:


Yak-9u

Yak-3

I think the difference alone with the cockpit position and the single piece windscreen on the 3 is quite substential optically speaking (even for similar looking aircraft) dunno what the guy on wikipedia was drinking

 

[Wurger]

Yep.. it is very likely the guy just mixed his all info on the Yak-9 and 3. As I have stated it above, although the Yak-9U based on the Yak-9T there was a lot of techical solutions for Yak-3 used. If you have a close up look at the fisrt shot in my post above (#2) you can notice that the 9U seems to have the Yak-3 full cockpit canopy. The caption of the image says it is 9U assembled by the factory in Omsk in 1944. There is no frame for the windscreen seen at all. But if you compare it with the shot of the Yak-3 also uploaded above, you may really get the idea that there were 9U with the windscreen made of one piece of prospex ( plexi ) glass though.

 

[Massimo Tessitori]

The Yak-9U of the first photo really had an one-piece windshield, but it was not representative of serie production.
Yak-3 and Yak-9D both had their cockpit in aft position, while Yak-9 T and M had in moved back position. 40cm is right.
All the planes with VK-107 had the canopy in back position: Yak-3VK-107, Yak-9U and P.
Yak-9U had a wooden rear fuselage as the Yak-3, and similar cooler configuration.
Yak-3s had smaller wings than Yak-9, and lighter landing gear with different door shape.

 

[wombat40]

that's pretty well correct on all counts, for further information I could recommend "Yakovlev's Piston-Engined Fighters" by Gordon & Khazanov Volume 5 on the Red Star Series. All aircraft fitted with larger cannon (37mm and in one case 45mm had the cockpit/canopy moved back 400mm). As the Yak 3 did not have this larger calibre item it canopy was in the "conventional" position

 

[Graeme]

but this quote (without a cited source ofc) made me doubt my knowledge on Yak fighters a bit,

Hi Alex.
Looking at the bibliography, possibly attributable to Gunston and Gordon?

 

[Massimo Tessitori]

This text is from Gordon, p.87. It is true only for the Yak-9U VK-105PF-2 first prototype, photos at pag.86 of the book of Gordon. Production Yak-9U had the VK-107 and the moved-back canopy. Eventually, production Yak-9U are very resemblant to the Yak-3VK-107, three prototypes plus (perhaps) 50 production ones that were without use.

 

[MiTasol]

I have made an experimant and I merged three shots .

Nice work and clarifies the differences nicely. I am very jealous of your graphics abilities.