Polikarpov Po-2: The Humble Biplane That Harassed an Army

The Polikarpov Po-2 was one of the most extraordinary aircraft of the Second World War: a slow, fabric-covered biplane designed in the 1920s as a trainer, which became one of the most numerous aircraft ever built and one of the most persistent weapons in the Soviet arsenal. Originally designated the U-2, the aircraft was renamed the Po-2 in 1944 in honour of its designer, Nikolai Polikarpov, who had died that year. Between 20,000 and 33,000 Po-2s were built, with most historians citing a figure of around 20,000 to 30,000, making it one of the most produced aircraft in history. It served as a trainer, a liaison aircraft, an ambulance, a crop duster and, most famously, a night bomber, flown by the all-female 588th Night Bomber Regiment, the Night Witches, whose daring low-level raids harassed German troops throughout the war on the Eastern Front.

The Po-2’s success as a night bomber was a triumph of improvisation. The aircraft was slow, with a maximum speed of only about 150 kilometres per hour, and it was unarmed in its original form, but these apparent weaknesses became strengths at night. The Po-2 could fly so slowly and so low that German fighters could not intercept it without stalling, and its wooden and fabric construction gave it a small radar signature. Its engine was quiet enough that German soldiers often heard it only when it was overhead, and its pilots learned to cut the engine and glide silently to their targets, dropping small bombs with remarkable accuracy. The Germans called the Night Witches’ aircraft the night witches, and they feared the sound of its engine in the dark.

Today the Po-2 is remembered as a symbol of Soviet ingenuity and of the courage of the women who flew it. A small number of Po-2s survive in museums, and restored examples have flown at airshows, where their slow, graceful flight is a reminder of a very different kind of air war. The Po-2’s story is a reminder that, in war, the simplest aircraft can sometimes be the most effective, and that courage and ingenuity can matter more than speed and firepower.

1. Key Facts

Field	Value
Type	Two-seat biplane trainer, light night bomber, liaison and utility aircraft
Origin	Soviet Union
Manufacturer	Polikarpov design bureau; built at numerous plants
Designer	Nikolai Polikarpov
First flight	24 June 1927 (as U-2)
Introduced	1929
Produced	20,000–33,000 (most sources cite around 20,000–30,000)
Crew	2 (pilot and observer, or instructor and pupil)
Length	Approximately 8.17 m (26 ft 10 in)
Wingspan	Approximately 11.40 m (37 ft 5 in)
Height	Approximately 3.10 m (10 ft 2 in)
Empty weight	Approximately 770 kg (1,698 lb)
Maximum take-off weight	Approximately 1,350 kg (2,976 lb)
Engine	Shvetsov M-11D five-cylinder radial, approximately 115 hp
Maximum speed	Approximately 150 km/h (93 mph)
Range	Approximately 630 km (391 miles)
Service ceiling	Approximately 3,000 m (9,840 ft)
Armament (bomber version)	Up to 250–350 kg of bombs on underwing racks; 1 × 7.62 mm ShKAS machine gun in the rear cockpit on some versions
Main operators	Soviet Air Force (VVS), Soviet civil aviation, Polish Air Force, other post-war users

2. Background and Development

A Trainer for a New Air Force

In the 1920s the Soviet Union was building a new air force from nothing, and it needed a simple, rugged trainer that could be built in large numbers and flown by inexperienced pilots. Nikolai Polikarpov, one of the Soviet Union’s leading aircraft designers, was given the task, and his answer was the U-2, a two-seat biplane of wooden construction with fabric covering, a small radial engine and fixed landing gear. The U-2 first flew on 24 June 1927, and it entered service in 1929, where it quickly became the standard trainer of the Soviet air force and of the civil flying clubs that trained a generation of Soviet pilots.

The U-2 was designed to be forgiving. It was stable, easy to fly and difficult to damage, and it could operate from rough grass fields with minimal maintenance. Its wooden structure could be repaired with simple tools, and its engine was a reliable five-cylinder radial that could be maintained by mechanics with little training. The aircraft was also versatile: it was used as a trainer, a liaison aircraft, an ambulance, a mail plane and a crop duster, and it became one of the most familiar sights in the Soviet Union, flying over farms, towns and airfields across the country. By the time Germany invaded in 1941, thousands of U-2s were in service, and the aircraft was a fixture of Soviet aviation.

From Trainer to Night Bomber

The U-2’s transformation into a bomber was an improvisation born of desperation. In the summer of 1941, the Soviet air force had lost thousands of aircraft, and it needed every bomber it could obtain. The U-2, with its ability to fly slowly and quietly at night, was an obvious candidate for night harassment bombing, and it was soon fitted with underwing racks for small bombs. The aircraft’s first night bombing missions were flown in 1941, and they were an immediate success: the U-2 could approach its target silently, drop its bombs with accuracy, and escape before the Germans could react. The aircraft’s slow speed, which would have been a fatal weakness in daylight, was a strength at night, when German fighters could not fly slowly enough to intercept it.

The U-2’s role expanded rapidly. It was used to drop supplies to partisans, to evacuate wounded soldiers from behind enemy lines, to fly liaison missions and to train pilots. The aircraft’s versatility made it indispensable, and its production continued throughout the war, with new factories building the aircraft even as the older plants were evacuated eastwards. In 1944, the aircraft was renamed the Po-2 in honour of Polikarpov, who had died in July of that year, and the new designation became the one by which the aircraft is best known today.

The Designer: Nikolai Polikarpov

Nikolai Polikarpov was one of the founders of Soviet aviation, a designer whose aircraft included the I-15 and I-16 fighters as well as the U-2. He was a brilliant engineer who worked under difficult conditions, and his designs were known for their simplicity and their ruggedness. Polikarpov died in 1944, before the end of the war, but his aircraft continued to serve, and the renaming of the U-2 as the Po-2 was a tribute to his contribution to Soviet aviation. The Po-2’s long service, which continued into the 1950s, was a fitting memorial to its designer.

3. Design

Airframe, Wings and Simplicity

The Po-2 was a two-bay biplane of wooden construction, with a fuselage built of wood and plywood and wings covered in fabric. The aircraft had two open cockpits, one behind the other, with the pilot in the rear and the observer or pupil in the front, and it was powered by a small radial engine mounted in the nose. The undercarriage was fixed, with two main wheels and a tail skid, and the aircraft could operate from rough grass fields with no prepared runway. The Po-2’s design was deliberately simple: there were no flaps, no retractable undercarriage and no complex systems, and the aircraft could be maintained by mechanics with basic tools and training.

The Po-2’s simplicity was its greatest strength. The aircraft could be built in factories that had no experience of aircraft production, and it could be repaired in the field with wood, fabric and glue. Its wooden structure was resistant to small-arms fire, and its fabric covering could be patched quickly. The aircraft’s low speed and light weight meant that it could land in fields and on roads, and it could be hidden in barns and forests, a useful quality for an aircraft that operated from forward airfields close to the front line.

Engine and Performance

The Po-2 was powered by the Shvetsov M-11D, a five-cylinder air-cooled radial engine producing about 115 horsepower. The engine was reliable and easy to maintain, and it gave the aircraft a maximum speed of about 150 kilometres per hour, a cruising speed of about 110 kilometres per hour and a range of about 630 kilometres. The aircraft’s service ceiling was about 3,000 metres, although in practice it rarely flew above 1,000 metres, and its climb rate was modest. The Po-2 was not a fast aircraft, but it did not need to be: its missions were flown at low level and at night, where speed mattered less than quietness and accuracy.

The Po-2’s engine was its most distinctive feature in the air: its low, throbbing sound was instantly recognisable, and German soldiers learned to fear it. The Night Witches’ pilots learned to cut the engine on their final approach, gliding silently to their targets, and the sudden silence, followed by the whistle of falling bombs, became one of the most feared sounds on the Eastern Front. The Po-2’s quiet engine, a consequence of its small size and low power, was a tactical asset that no other bomber possessed.

Armament and Bomb Load

In its bomber version, the Po-2 carried up to 250 to 350 kilograms of bombs on racks under its lower wings, usually six small bombs of 50 kilograms each. The bombs were released by the observer in the front cockpit, who aimed them by eye, and the aircraft’s low speed and low altitude made accurate bombing possible. Some Po-2s were fitted with a 7.62 mm ShKAS machine gun in the rear cockpit, operated by the observer for self-defence, and later versions carried a more powerful engine and a heavier bomb load. The Po-2’s armament was light, but it was enough for its mission: to harass, to disrupt and to deny the enemy sleep.

4. Variants

The U-2 Trainer and Civil Versions

The original U-2 was built in a number of versions, including the U-2 trainer, the U-2S ambulance, with a stretcher carried in the rear fuselage, the U-2SP, a three-seat version, and the U-2AP, an agricultural version used for crop dusting. The U-2 was also built as a floatplane, the U-2M, and as a seaplane trainer. These civil and training versions were the aircraft’s main role before the war, and they continued in production throughout the war, training the pilots who flew the Soviet Union’s fighters and bombers.

The Po-2 Night Bomber

The night bomber version of the Po-2, designated the U-2VS and later the Po-2VS, was the aircraft’s most famous variant. It was fitted with underwing bomb racks, a bomb sight and, in some aircraft, a rear machine gun, and it was flown by the night bomber regiments, including the 588th, whose pilots became known as the Night Witches. The Po-2VS was also used for dropping supplies to partisans, for liaison and for reconnaissance, and it was one of the most versatile aircraft in the Soviet inventory. The night bomber version was built in large numbers, and it remained in service after the war, when it was used by the Polish Air Force and by other air forces in Eastern Europe.

Post-War and Export Versions

After the war, the Po-2 continued in production in the Soviet Union and in Poland, where it was built under licence as the CSS-13. The Polish-built aircraft served with the Polish Air Force and with civil operators, and they remained in service into the 1950s. The Po-2 was also exported to a number of countries, including China, North Korea and Yugoslavia, where it was used as a trainer and a utility aircraft. The aircraft’s long production run, which ended in the early 1950s, made it one of the longest-serving aircraft of its generation.

5. Operational History

The Night Witches

The most famous Po-2 unit was the 588th Night Bomber Regiment, formed in 1941 as an all-female unit under the command of Yevdokiya Bershanskaya. The regiment’s pilots, navigators and ground crew were all women, and they flew the Po-2 on night harassment missions against German troops, dropping small bombs on positions, supply dumps and airfields. The regiment flew more than 23,000 sorties during the war, and its pilots became known to the Germans as the Night Witches, a name that reflected both their skill and the fear they inspired. The regiment’s pilots flew in open cockpits, in the cold and the dark, with no parachutes in the early years and with only a map and a compass to navigate by, and their courage became legendary.

The Night Witches’ tactics were simple and effective. They flew in groups of three, with the first two aircraft acting as decoys, drawing the attention of German searchlights and anti-aircraft guns, while the third aircraft cut its engine and glided silently to the target, dropping its bombs before restarting the engine and escaping. The tactic was dangerous, and the regiment lost many pilots, but it was effective, and the Germans came to dread the sound of the Po-2’s engine in the night. The regiment’s pilots included Nadezhda Popova, Yevdokiya Nosal and Natalya Meklin, who became Heroes of the Soviet Union, and the regiment itself was awarded the Guards title and renamed the 46th Guards Night Bomber Regiment.

Liaison, Ambulance and Partisan Supply

Beyond the night bombing role, the Po-2 served in a host of other duties. It flew liaison missions, carrying officers and messages between headquarters, and it evacuated wounded soldiers from forward airfields, landing in fields close to the front line to pick up casualties. It dropped supplies to partisans operating behind German lines, landing in forest clearings to deliver arms, ammunition and medical supplies, and it flew reconnaissance missions, observing German positions from low altitude. The Po-2’s ability to operate from rough fields and to fly slowly and quietly made it ideal for these tasks, and it became the workhorse of the Soviet air force’s light aviation.

The Po-2 After the War

After the war, the Po-2 continued in service with the Soviet air force and with civil operators, where it was used as a trainer, a crop duster and a utility aircraft. It served in the Korean War, where North Korean Po-2s flew night harassment missions against United Nations forces, a role that echoed the Night Witches’ work on the Eastern Front. The aircraft remained in service into the 1950s, when it was finally replaced by more modern trainers and helicopters. The Po-2’s long service, from 1929 to the 1950s, is a testament to the soundness of its design and to the affection in which it was held by the pilots who flew it.

The Po-2 in Korea

In the Korean War, the Po-2 was used by North Korean forces for night harassment bombing, and it became known to American troops as Bedcheck Charlie, a name that reflected the regularity of its nightly visits. The Po-2’s slow speed made it difficult for American jets to intercept, and it was credited with a number of successful attacks on airfields and supply dumps. The aircraft’s use in Korea was a final chapter in its combat career, and it demonstrated that the Po-2’s qualities as a night bomber remained relevant even in the jet age.

6. Performance and Specifications

Strengths in Combat

The Po-2’s strengths were its simplicity, its reliability and its ability to fly slowly and quietly at night. Its wooden construction was easy to repair, its engine was reliable, and its low speed made it difficult for German fighters to intercept. The aircraft’s small size and fabric covering gave it a small radar signature, and its ability to operate from rough fields made it ideal for forward operations. The Po-2 was also cheap to build and easy to fly, and it could be operated by pilots with minimal training. These qualities made it one of the most effective night harassment aircraft of the war.

Weaknesses and Limitations

The Po-2’s weaknesses were those of a 1920s trainer: it was slow, unarmoured and vulnerable to ground fire and to fighters in daylight. Its open cockpits exposed its crew to the cold and the wind, and its small bomb load limited the damage it could inflict. The aircraft’s range was short, and its ceiling was low, and it could not operate in bad weather. The Po-2 was a night aircraft, and it was at its best when the darkness protected it; in daylight, it was an easy target, and its pilots knew it. The Po-2’s success was a product of its role, not of its performance, and it is a reminder that an aircraft’s effectiveness depends on how it is used.

7. Comparison

The Po-2 and the German Night Bombers

The Po-2’s German counterparts were the Heinkel He 46 and the Henschel Hs 126, both of which were used for night harassment bombing on the Eastern Front. The German aircraft were faster and more heavily armed than the Po-2, but they were also more complex and more expensive, and they were not as well suited to the low-level night role. The Po-2’s simplicity and its ability to fly silently made it a more effective night bomber, and the Germans’ own night harassment units, the Nachtschlachtgruppen, were inspired in part by the Soviet example. The comparison shows that, in night harassment bombing, simplicity and quietness mattered more than speed and firepower.

The Po-2 and the British Lysander

The Po-2’s closest Western contemporary was the Westland Lysander, a British liaison and army co-operation aircraft that was also used for night operations, dropping agents into occupied France. The Lysander was faster and more heavily armed than the Po-2, and it was a more modern aircraft, but it was also more complex and more expensive. The Po-2 was simpler, cheaper and more numerous, and it was used in a wider range of roles. The two aircraft illustrate different approaches to the same problem: the Lysander was a specialised aircraft for a specialised role, while the Po-2 was a general-purpose aircraft that could do almost anything.

8. Legacy

The Night Witches in Memory

The Po-2’s legacy is inseparable from the Night Witches, whose story has become one of the most celebrated chapters in the history of women in war. The regiment’s pilots have been honoured in books, films and memorials, and their story continues to inspire new generations. The Night Witches’ courage, flying in open cockpits at night in an aircraft that was little more than a trainer, is a testament to the human spirit, and it is a reminder that the Soviet Union’s victory on the Eastern Front was won by ordinary people doing extraordinary things. The Po-2 was their aircraft, and its story is their story.

The Po-2’s Place in Aviation History

The Po-2’s place in aviation history is secure. It was one of the most numerous aircraft ever built, and it served in more roles than almost any other aircraft of its generation. Its design, simple and rugged, influenced the development of light aircraft in the Soviet Union, and its long service, from 1929 to the 1950s, is a testament to its soundness. The Po-2’s story is a reminder that the most important aircraft in a war are not always the fastest or the most heavily armed, but the ones that are available, reliable and versatile. The Po-2 was all three, and it earned its place in history.

9. Surviving Examples

Museums and Flying Examples

A small number of Po-2s survive in museums, including examples at the Central Air Force Museum at Monino in Russia, the Polish Aviation Museum in Krakow and the National Museum of the United States Air Force in Dayton, Ohio. A few Po-2s have been restored to flying condition, including aircraft in Russia and in the United States, and they fly at airshows, where their slow, graceful flight is a reminder of a very different era of aviation. The surviving aircraft are precious, since so few were preserved after the war, when most Po-2s were scrapped or left to decay.

Wrecks and Reconstructions

Po-2 wrecks have been recovered from crash sites in Russia and Eastern Europe, where the aircraft came down during the war, and some have been used to support the restoration of flying examples. The aircraft’s wooden construction has often decayed, but metal components, including engines and instruments, have survived and are preserved in museums. The scarcity of complete survivors makes the flying examples all the more valuable, and their preservation is a tribute to the volunteers and enthusiasts who have kept the Po-2 flying.

10. Frequently Asked Questions

What does Po-2 stand for?
Po-2 stands for Polikarpov, the aircraft’s designer, Nikolai Polikarpov. The aircraft was originally designated the U-2, for uchebny, meaning training, and it was renamed the Po-2 in 1944 after Polikarpov’s death.

How many Po-2s were built?
Between 20,000 and 33,000 Po-2s were built, with most sources citing a figure of around 20,000 to 30,000, making it one of the most produced aircraft in history.

Who were the Night Witches?
The Night Witches were the pilots of the Soviet 588th Night Bomber Regiment, an all-female unit that flew the Po-2 on night harassment bombing missions against German forces. The regiment flew more than 23,000 sorties and became one of the most celebrated units of the war.

Why was the Po-2 so effective at night?
The Po-2 could fly very slowly and quietly, and its pilots learned to cut the engine and glide silently to their targets. German fighters could not fly slowly enough to intercept it, and its wooden and fabric construction gave it a small radar signature.

What was the Po-2’s top speed?
The Po-2’s maximum speed was about 150 kilometres per hour (93 miles per hour), making it one of the slowest combat aircraft of the Second World War. Its slow speed was a strength at night, when it made the aircraft difficult to intercept.

Where can I see a Po-2 today?
Po-2s are displayed at the Central Air Force Museum at Monino in Russia, the Polish Aviation Museum in Krakow and the National Museum of the United States Air Force in Dayton, Ohio. A few restored examples also fly at airshows.

11. Sources

• Yefim Gordon, Polikarpov’s Biplane Fighters (Red Star series).
• Bruce Myles, Night Witches: The Untold Story of Soviet Women in Combat (Academy Chicago Publishers).
• The Central Air Force Museum, Monino, Po-2 collection records.
• The Polish Aviation Museum, Krakow, Po-2 collection records.
• Osprey Publishing, Aircraft of the Aces series, Soviet night bomber volumes.
• Wikipedia, Polikarpov Po-2.