Polikarpov Po-2 - Variants and Design Stages

Variants and Design Stages

• U-2: Basic model, built in large numbers as a two-seat primary trainer. It was also built in many different versions, both as civil and military aircraft. The U-2 variants also included a light transport, utility, reconnaissance and training aircraft. Power plant was the M-11 radial piston engine of 75 kW (100 hp). Later models were also equipped with uprated M-11 engines of 111 kW (150 hp). Some aircraft were fitted with a rear closed cabin, other were fitted with sledges or floats.
• U-2A: Two-seat agricultural crop dusting aircraft, powered by a 86 kW (115 hp) M-11K radial piston engine. Later redesignated Po-2A after 1944.
• U-2AO: Two-seat agricultural aircraft.
• U-2AP: Agricultural aircraft, with a rear cab replaced with a container for 200–250 kg (441-551 lb) of chemicals. 1,235 were built in 1930–1940.
• U-2G: This experimental aircraft had all the controls linked to the control column. One aircraft only.
• U-2KL: Two aircraft fitted with a bulged canopy over the rear cabin.
• U-2LSh: Two-seat ground-attack, close-support aircraft. The aircraft were armed with one 7.62 mm (0.30 in) ShKAS machine-gun in the rear cockpit. It could also carry up to 120 kg (265 lb) of bombs and four RS-82 rockets. Also known as the U-2VOM-1.
• U-2LPL: Experimental prone-pilot research aircraft.
• U-2M: This floatplane version was fitted with a large central float and two small stabilizing floats. Not built in large numbers. Also known as the MU-2.
• U-2P: Floatplane version, built only in limited numbers, in several variants with different designations.
• U-2S: Air ambulance version, built from 1934. It could take a physician and an injured on a stretcher on a rear fuselage, under a cover. Variant U-2S-1 from 1939 had a raised fuselage top upon the stretcher. From 1941 there were also used two containers for stretchers, that could be fitted over lower wings or two containers for two seating injured each, fitted under lower wings.
• U-2SS: Air ambulance aircraft.
• U-2ShS: Staff liaison version, built from 1943. It had a wider fuselage and a closed 4-place rear cab.
• U-2SP: Civil transport version, could carry two passengers in open individual cabs, built from 1933. Other roles included aerial survey, and aerial photography. A total of 861 were built between 1934 and 1939.
• U-2SPL: This limousine version was fitted with rear cabin for two passengers.
• U-2UT: Two-seat training aircraft, powered by a 86 kW (115 hp) M-11D radial piston engine. Built in limited numbers.
• U-2LNB: Soviet Air Force night attack version, built from 1942. Armed with one 7.62 mm (0.30 in) ShKAS, plus up to 250 kg of bombs under the wings for land support. Earlier aircraft were converted to improvised bombers from 1941.
• 'U-2VS : Two-seat training and utility aircraft. Later redesignated Po-2VS after 1944.
• U-2NAK: Two-seat night artillery observation, reconnaissance aircraft. Built from 1943.
• U-3: Improved flying training model, fitted a 149 kW (200 hp) seven cylinder M-48 radial engine.
• U-4: Cleaned-up version with slimmer fuselage; not built in large numbers.
• - (Total U-2 manufacture: 33,000)
• Po-2:Post-war basic trainer variant.
• Po-2A: Post-war agricultural variant.
• Po-2GN: "Voice from the sky" propaganda aircraft, fitted with a loud speaker.
• Po-2L : Limousine version with an enclosed passenger cabin.
• Po-2P : Post-war floatplane version; built in small numbers.
• Po-2S: Post-war air ambulance variant, with a closed rear cab.
• Po-2S-1: Post-war ambulance version, similar to the pre-war U-2S.
• Po-2S-2: Post-war ambulance version, powered by a M-11D radial piston engine.
• Po-2S-3: Post-war ambulance version, which had two underwing containers, each one was designed to transport one stretcher patient. Also known as the Po-2SKF.
• Po-2ShS: Staff communications aircraft, fitted with an enclosed cabin for the pilot and two or three passengers.
• Po-2SP: Post-war aerial photography, geographic survey aircraft.
• RV-23: This floatplane version of the U-2 was built in 1937. It was used in a number of seaplane altitude record attempts. The RV-23 was powered by a 529 kW (710 hp) Wright R-1820-F3 Cyclone radial piston engine.
• CSS-13: Polish licence version, built in Poland in WSK-Okęcie andWSK-Mielec after World War II (about 500 built in 1948–1956).
• CSS S-13: Polish ambulance version with a closed rear cab and cockpit and Townend ring (53 built in WSK-Okęcie in 1954-1955, 38 converted to S-13).
• E-23: Research version, built in the Soviet Union in 1934, for research into inverted flight.