Technical data
Type	La-5FN
Function	Fighter Prototype	Series Fighter
Year	1943
Crew	1
Engine	ASh-82FN
Takeoff Power	1850hp
Power at 1550m	1630hp
Power at 4500m	1500hp
Length	8.60m
Height	?m
Wingspan	9.80m
Wing area	17.50m2
Empty weight	2706kg	2828kg
Loaded weight	3168kg	3290kg
Wing Load (kg/m2)	181	188
Power load (kg/hp)	2.17	2.25
Speed at altitude
0m (boosted)	593km/h	583km/h
6250m	648km/h	634km/h
Landing	137km/h	138km/h
Landing Roll	?m	?m
Takeoff Roll	?m	?m
Turn time	18.5sec	18.5sec
Range	?km	?km
Flight Endurance	?h	?h
Ceiling	11200m	10750m
Climb
5000m	4.7min	5.2min
Payload
Fuel+Oil	345+50kg
Armament
Guns	2*20mm ShVAK
Bombs	4*50kg

During offensive stage of the Battle for Stalingrad new Lavochkin aircraft made its debut. In Summer 1943 the La-5FN in substantial numbers, making massive show during the Kursk Bend battle. While the La-5 was even with most of German front line fighters at low/medium altitudes, it still had some shortage in climb. With new 'Lavochkin' arrival this gap was filled.

Externally La-5FN differed from the late production La-5 by more articulated air intake on the top of the engine cowling, providing more room (and more air) demanded by new ASh-82FN supercharged engine with direct fuel injection. Fairings on the cooling/exhaust side louvers were removed. Slightly larger new VISh-105V (3m diameter) propeller was installed.

But 'hidden' changes were even more substantial. More powerful engine with better altitude performance was supplemented by airframe improvements. Those included new suction operated leading edge slats and radically improved balance of controls (following the TsAGI expertise). As a result, La-5FN and later aircraft of this line became the most lightly controlled fighters of their time. In addition, large ailerons provided it with excellent roll characteristics.

Improvements in wing structure allowed to use larger fuel tanks, but this opportunity was realised only on few batches. Commonly, tanks volume as same or even smaller than on the La-5.

La-5 pilots complains about excessive cockpit heat were taken into account, and La-5FN provided sufficient comfort. Spartan cockpit instrumentation was absolutely sufficient for daylight prop fighter.

In effort to improve high altitude performance of the La-5FN small batch of La-5FN-TK was built. Those fighters were equipped with turbo-chargers designed by Treskin. Quite commonly, marginal high altitude advantages were outweighted by performance losses at low and medium altitudes - where 'Lavochkins' were mostly used. High altitude fighter on Eastern front was not a pressing priority, and this project was abandoned.

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Drawing from Watson's Military, used to produce a background for this page;

Predecessors	Modifications
La-5	La-7	LA-5FN-TK
	La-5 '206'	VI