|Power at 0m||1,850hp|
|Power at 4,650m||1,460hp|
|Weights and loads|
|Wing Load (kg/m2)||197|
|Power load (kg/hp)||2.38|
|Gun type (Position)||Ammo|
|2*20mm ShVAK, engine cowling||200rpg|
With the service introduction of the La-5FN the Soviet Air Forces for the first time had a fighter superior to the Messerschmitt Bf 109G. But it was also evident, that this advantage would not last long without further improvements to the basic design. A further significant increase of the power of the ASh-82FN engine was considered impossible by the Shvetsov team, however, and more powerful alternative engines like the ASh-71F proved too unreliable. So the only way to obtain further performance improvements lay in additional weight reductions and careful refinements of the La-5FN's aerodynamics.
With this in mind and the promising results obtained during extensive tests of an aerodynamically improved La-5 at TsAGI's huge T-104 wind tunnel in Zhukovskij during 1943, the standard La-5FN with the serial number 39210206 (hence the designation La-5 '206') was modified by the TsAGI. The following modifications were carried out:
Flight testing of this aircraft took place at the LII between December 16, 1943 and February 10, 1944. These tests were carried out by test pilot N. V. Adamovich and engineer V. Molochayev. The results fully confirmed the calculations and predictions made by TsAGI. Although the La-5 '206' was about 150kg heavier than the standard La-5FN, at an altitude of 6,150m it was 64km/h faster.
The TsAGI modifications and recommendations were immediately taken into account by S.A. Lavochkin. He took over the work to incorporate these (and some own) improvements into production fighters. This finally led (via the La-5FN Model 1944 prototype) to the La-7.