Yakovlev Yak-9

The Yak-9 was the fourth step in a line that had begun with the Yak-1 of 1940 and passed through the Yak-7 — a two-seat trainer that turned out to make a better fighter than the aircraft it was built to teach people to fly. Each step was a refinement of the same basic machine: a small, light, wooden-and-steel fighter built around the only engine the Soviet Union had in quantity, the Klimov VK-105.

What made the Yak-9 different was a material. By 1942 Soviet industry had enough duralumin to build wing spars in metal rather than wood, and metal spars are lighter for the same strength. The weight saved did not go into performance: it went into volume — space and lifting capacity for more fuel, heavier guns and equipment. The Yak-9 was, from the start, the version of the family designed to be adapted.

In its standard form it was unremarkable on paper and exactly right in practice: about 600 km/h on roughly 1,180 hp, one 20 mm ShVAK cannon firing through the propeller hub and one or two 12.7 mm machine guns above the engine. Nothing about those figures would have impressed a Spitfire pilot. They were, however, achievable by factories staffed largely by women and teenagers, working in buildings that had been moved a thousand kilometres east ahead of the German advance.

The aircraft was easy to fly, easy to maintain on a forward strip and easy to repair when damaged, and it arrived in numbers. Production ran from 1942 to 1948 and reached 16,769 aircraft — 14,579 of them during the war — making it the most-produced Soviet fighter of the conflict and one of the most-produced fighters ever built.

The Yak-9 reached the front late in 1942, in time for the battle that reversed the war. Over Stalingrad the Soviet fighter regiments were still losing badly, but for the first time they were losing while contesting the sky rather than being swept from it. Their most valuable work was not against German fighters at all: it was against the airlift, the stream of Ju 52s and He 111s trying to keep the encircled Sixth Army supplied. Fighters that could reach the transport corridors and stay there turned a difficult supply operation into an impossible one.

That was the aircraft’s real function throughout its career. The Yak-9 was not built to establish personal superiority over a Bf 109 — the best German pilots retained their edge to the end — but to be present, everywhere, in enough numbers that German fighters could no longer be everywhere at once. It was a machine for winning an attritional air war rather than a duel.

The most striking use of that spare capacity was the Yak-9T. Into the vee of the engine block, firing through the propeller hub, went the 37 mm NS-37 cannon — a weapon so long that the cockpit had to be moved back some 40 cm to keep the aircraft in balance, and so powerful that the airframe visibly slowed when it fired. Ammunition was about 30 rounds, and pilots were taught to shoot in bursts of two or three.

It did not need many. A single 37 mm hit could take a wing off a fighter or break up a twin-engined bomber, and the type was also used against river craft, trains and thin-skinned armour. The idea was pushed further still with the Yak-9K, carrying a 45 mm gun — an anti-tank weapon in a single-seat fighter, and about as far as the concept could reasonably be taken.

The other direction the airframe was stretched was distance. Soviet fighters were notoriously short-legged, which mattered little while the front was being defended and a great deal once the Red Army was advancing hundreds of kilometres. The Yak-9D and the further-stretched Yak-9DD added wing tankage, taking range from about 875 km to well over 1,300.

The most remarkable use of them came in 1944, when Yak-9DDs flew from the Soviet Union to southern Italy to escort Allied supply flights to the Yugoslav partisans — Soviet fighters operating from Allied airfields in the Mediterranean, at the opposite end of Europe from the front they had been built for. There was also a Yak-9B with an internal bay for up to 400 kg of bombs, the one variant that asked the airframe to do something it was not really suited to.

The definitive version arrived at the end of 1944. The Yak-9U combined a cleaned-up, aerodynamically refined airframe and a larger wing with the VK-107A engine of about 1,650 hp, and reached roughly 700 km/h — the fastest Soviet piston-engined fighter of the war, and a genuine match for anything the Luftwaffe still had flying.

It came with the problem that had dogged the VK-107 from the beginning: the engine ran hot, overheated in sustained combat and wore out quickly, and the early production aircraft suffered accordingly. Refined post-war as the Yak-9P, the type went on serving Soviet client states, and North Korean Yak-9s met American aircraft over Korea in 1950 — an obsolete piston fighter opening a jet war.

The Yak-9 is the answer to a question the Western air forces never had to ask: what do you build when you cannot have a good engine, cannot spare much aluminium, and need fighters by the thousand next year? Yakovlev’s answer was a single adaptable airframe — simple enough to be built by an unskilled workforce in factories that had been dismantled and moved a thousand kilometres east, and flown by pilots with a few dozen hours — and then reissued as a tank-buster, an escort or a bomber as the war demanded. Nothing about it was excellent; everything about it was sufficient, available and repairable.

Against the Yak-3, its stablemate, the contrast is exact. The Yak-3 was a specialist — the lightest possible airframe, optimised to dominate below 4,000 m, and superb at it. The Yak-9 was the generalist that actually equipped the Soviet fighter force, and the numbers say which mattered more: 16,769 built, more than every British fighter type of the war except the Spitfire, and the aircraft in which the VVS learned to hold the sky over its own armies.

• Yefim Gordon, Yakovlev’s Piston-Engined Fighters (Midland, Red Star).
• George Mellinger, Yakovlev Aces of World War 2 (Osprey, Aircraft of the Aces 64).
• Hans Seidl, Stalin’s Eagles (Schiffer).