The last LaGGs

I-105 and I-105-2

By Massimo Tessitori

File updated on July 2, 2018

Go back to Sovietwarplanes Pages main page
go back to LaGG-3 main page
Go back to LaGG-3 evolution, profiles and photos main page


In 1943, the Design Bureau led by Vladimir P. Gorbunov created a further update of the original LaGG-3, still in production in its lightened form at Zavod 31 in Tbilisi.



The first prototype of I-105 (I for Istrebitel, fighter) was built in May 1943. Compared to late production LaGG-2 (series 70) the new plane featured:

The test flight were satisfying, showing an increase of speed of 25 km/h compared to productio LaGG-3s of May 1943, a good turning time of 16 seconds, a climb time to 5000 m of 4.7 minutes and no troubles in handling.


image of the first prototype I-105 taken on January 1944, much after its maiden flight in May 1943. .

Note that the windshield, the engine and the 4-tubes exhaust stakes were the same of production LaGG-3s.

The black-white painting of the prop blades and of the wheel hubs is noteworthy.


Profile of I-105.

The plane featured a standard grey-grey camouflage of AMT-11 and 12, with AMT-7 blue undersurfaces.


I 105-2

The second prototype I-105-2, had some improvements:

  • the more advanced M-105PF-2 emgine, as on Yak-3;
  • prop blades extended on their root to increase thrust;
  • modified panelling of the nose;
  • new 6-pipes exhaust stacks as on Yak-3;
  • armament of one 23 mm VYa gun firing through the prop's hub (instead of 20 mm ShVAK) and a 12,7 mm UBS (the same as I-105);
  • frameless windshield as on Yak-3;
  • the doors of the main landing gear were a bit reduced and were more similar to that of standard LaGG-3s..
The image from behind shows
This image shows clearly the new profile of the fuselage,





This image shows the small size of the stars under the wings and the distance between the new air intakes for the oil coolers.


Profile of I-105-2.

It featured the standard grey-grey camouflage

The prototype was ready to fly only in February 1944 because of delays, and the state tests were made only in May-June 1944.

The state tests weren't very satisfying: the gross weight was 2875 kg, the max speed was 554 km/h at sea level and 618 km/h at 3400 m; it reached 5000 m of altitude in 4.8 minutes.

The maximum speed could be sustained only for 3 or 4 minutes because of water and oil overheating. These performances were inferior to those of the Yak-1M, the prototype of Yak-3, already tested in October 1943.

The program of modernization of the LaGG-3 was deleted, and Zavod 31 in Tbilisi was converted to the production of Yak-3s.


this work collects a lot of photos from many sources, not always identified and mentioned.
If someone has rights on the images reproduced on this site, please don't feel hurted, email to me and I shall provide to remove or to credit them.


(remove (nospam))