La-5, S.A.Lavochkin

After designing the LaGG-3, the designers split. Improved production and experimental variants of this aircraft with water-cooled engines also did not provide a satisfactory solution. Time came to make a radical solution. It became an installation of the M-82 14-cylinder radial air-cooling engine, which was lighter and much more powerful than engines of M-105 family. What was also essential, M-82 production was well set and huge stocks of this engine were available. Created to power single-engine bombers of the Su-2 class in rapid advance war, it just waited for another airframe to be fitted to.

V.P.Gorbunov and M.I.Goudkov came up with their solutions, slightly different by the degree of modifications to the LaGG-3. But their conversions (LaG-5 and Gu-82) had only limited success.

S.A.Lavochkin also managed to modify the LaGG-3 to accept this engine, despite the lack of official support. Lavochkin's factory was taken over by another KB, and Factory N°153 (Novosibirsk) was taken over by A.S.Yakovlev - the Yak-1 was in production there in parallel with the LaGG-3. S.A.Lavochkin was left with only a nucleus of his team in Tbilisi. He was so much out of official favour, that factory director refused to cooperate (with potential saboteurs and enemy of the people). La-5 prototype was assembled and kept out in the open...

Aircraft was ready in the very end of 1941. After factory trials La-5 was evaluated (May 1942) at LII and NII VVS (pilots A.P.Yakimov and A.G.Kubyshkin and Saginov).

Ten pre-production aircraft were found 40 to 50km/h slower than the prototype. Specially assigned group of TsAGI airdynamic experts traced problem to gaps in the engine cowling, and it was quickly cured. Vibration problems caused by lack of propeller blades balance also was fixed, but when two aircraft were lost in fatal accidents due to wing break off, test flights were halted. Only after exhaustive search and ground tests Lavochkin found the cause. Factory workers hammered in holes for the wing attachment bolts to make them larger and easier to assemble - but weakening the wing below design brackets.

After positive conclusion of trials La-5 was rushed in production and front-line service. First regiments manned with factory pilots arrived to Stalingrad in September. As many as 1129 were assembled during 1942.

Aircraft used same delta-wood technology as the LaGG-3, and shared a lot of components. Early batches even had 2-layer nose section: one (inner) inherited from LaGG-3 and outer - just an airdynamic transition from large diameter M-82 cowling to slim LaGG-3 fuselage. Without production interrupt, numerous changes were made. Delta-wood relied on imported epoxy, and was gradually replaced by thicker (but less dense) pine parts - and later by metal ones. Since 1943 fuselage behind the cockpit was lowered, providing better view for pilot.

From the very beginning production La-5 aircraft had retractable tailwheel (fixed on LaGG-3).

Flow of cooling air was provided by pair of large adjustable louvers on each side of fuselage. This solution proved to be no less efficient than commonly used 'all-round' cooling gills, but more technological and reliable. It became a common feature for all line of Lavochkin's piston engined fighters. On La-5 those louvers had an articulated fairing (covering large diameter joint exhausts), deleted in later aircraft of this line. Other 'mark' of production La-5 was a step-shaped nose intake - pushed up in later models with supercharged engines.

In 1943 more powerful engines were fitted. Experiment with M-71 was officially discouraged after Kremlin meet between Stalin, Minister of the Aircraft Industry A.I.Shakhurin and Shakhurin's deputy A.S.Yakovlev (rival designer, by chance).

Boosted M-82F was installed on some batches of production aircraft. Those differed by Cyrillic 'F' painted on the engine cowling. All M-82F powered had cut-down upper fuselage, and those aircraft are often referred as La-5F. But this is not an official designation and number of 'Lavochkins' with all-around canopy had an original M-82 engine.

Like all Soviet aircraft, it offered little in the way of cockpit sophistication and pilot comforts. In Summer time cockpit ventilation was insufficient, and pilots complained about excessive heat coming from the engine. But as a fighting aircraft, however, it was exceptional. La-5 inherited 2-level neutral gas protection of fuel tanks that was used on the LaGG-3. With less vulnerable radial engine La-5 was very hard-to-kill aircraft. Pilot was protected by 10mm armor seat back.

Built in few different variants, La-5 is often poorly represented by Western sources. Designation used are often wrong (like never existed LaGG-5) or misused like the LaG-5. Some sources mix La-5 with La-5FN and even with La-7...

Early La-5, unknown author, photo (48k) from Lavochkin design bureau Home Page;

References	Links
"History of aircraft construction in the USSR", Vol.2 p.219...220; "Russian aircraft since 1940" by Jean Alexander, p.168...171;	La-5 Lavochkin La-5 (precisely, La-5FN) La-5 at Watson's collection La-5 in Air Warrior La-5 profile... quite a mix. The Lavochkin La-5 by Microsoft... Gates invented La-5!!!!! La-5, Lavochkin Europe WWII aircraft 1/72 early production Lavochkin La-5 Fighters - comparatively simple, small, and quick, aircraft... Aircraft of Europe in Air Warrior La-5 in Air Warrior	Scale plans - has detailed drawings ...another detailed drawing at ScaleEaro Many drawings, early La-5 included Lavochkin La-5 Modeling La-5 more on La-5/7 modeling... and more... Lavochkin at WWW.AVIATION.RU La-5 and La-7 at Soviet aircraft Aircraft of the VVS (Soviet Air Force) Ivan Kozhedub - Top Soviet Ace. Squadron Signal #1169 La 5/7 Fighters in Action (Review) Lavochkin La-5 and La-7 Le Lavotchkin 5

Created September 27, 1999

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