The Yakovlev AIR-3 was a 1920s Soviet

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 two-seat general aviation monoplane

Monoplane

A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...

 designed and built by Aleksandr Sergeyevich Yakovlev.

Development

Following his design of the earlier AIR-1

Yakovlev AIR-1

The Yakovlev AIR-1 was a 1920s Soviet two-seat light biplane the first aircraft designed and built by Aleksandr Sergeyevich Yakovlev.-Development:...

 and AIR-2, Yakovlev was taken on as a student at the Nikolai Zhukovsky Air Force Engineering Academy, where he designed the AIR-3, which was similar to the earlier AIR-2 biplane but with a strut-braced high-wing parasol wing

Parasol wing

A parasol wing monoplane is an aircraft design in which the wing is not mounted directly to the fuselage, but rather, the fuselage is supported beneath it by a set of struts, called cabane struts...

. Powered by 60 hp Walter NZ-60 radial piston engine, the AIR-3 was also known as Pionerskaya Pravda after the Pionerskaya Pravda

Pionerskaya Pravda

Pionerskaya Pravda is an all-Russian newspaper. Initially it was an all-Union newspaper of the Soviet Union. Its name may be translated as "Truth for Young Pioneers"....

, a young-communist newspaper, which had raised funds for the construction from its readership. On 6 September 1929 the aircraft was flown non-stop between Mineralnye Vody

Mineralnye Vody

Mineralnye Vody is a town in Stavropol Krai, Russia, which lies along the Kuma River and the main rail line between Rostov-on-Don and Baku . Population:...

 and Moscow

Moscow

Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...

, a distance of 1835 km, achieving two light aircraft world records.

In 1930 the design was refined as the Yakovlev AIR-4 with a new split-axle landing gear

Landing Gear

Landing Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...

, wider cockpits fitted with entrance doors and extra fuel.

One AIR-4 was modified as the Yakovlev AIR-4MK in 1933 to test nearly full span split flaps

Flap (aircraft)

Flaps are normally hinged surfaces mounted on the trailing edges of the wings of a fixed-wing aircraft to reduce the speed an aircraft can be safely flown at and to increase the angle of descent for landing without increasing air speed. They shorten takeoff and landing distances as well as...

. Floating wing-tips, which provided roll control, were added to release as much trailing edge as possible for the flaps.

A military liaison variant of the AIR-4, the Yakovlev AIR-8, was also produced in 1934 fitted with a 85 hp Siemens

Siemens

Siemens may refer toSiemens, a German family name carried by generations of telecommunications industrialists, including:* Werner von Siemens , inventor, founder of Siemens AG...

 engine and constant chord wings of greater area.

Kozlov PS

After a preliminary experiment using a Polikarpov U-2, Professor Sergei Grigorevich Kozlov, of the Nikolai Zhukovsky Air Force Engineering Academy, modified a Yakovlev AIR-4, in 1935, to produce the Kozlov PS (Prozrachnyy Samolyot — transparent aircraft). Fabric covering on the fuselage and wings was replaced with a transparent plastic material, called cellon or Rhodoid, and the opaque structure was painted with a white paint mixed with aluminium powder. Trials with ground and airborne observations confirmed Kozlov's theories, with the bonus of excellent visibility for the crew. After the initial success, the film was found to become opaque through dirt collection and the effects of the sun, diminishing the invisibility effect.

Kozlov proposed an invisible single-seat reconnaissance aircraft using the transparent plastic material, but doubts about structural strength of the material precluded development. Further studies into transparent aircraft were ordered from the experimental institute headed by Pyotr I. Grokhovskii but no more transparent aircraft were built using Kozlov's methods.

AIR-3

Two-seat monoplane with a 60 hp Walter NZ-60 radial piston engine developed from the Yakovlev AIR-2. Only one AIR-3 was built.

AIR-4

Improved variant fitted with increased fuel capacity and modified landing gear. At least five AIR-4 aircraft were built.

AIR-4MK

. For research into high lift sytems for approach control, a single AIR-4 (regn. CCCP-E-31) was modified with full span split flaps, with floating wing-tips rotating around transverse axles for roll control.

Kozlov PS

A single AIR-4 was modified by Sergei G. Kozlov to demonstrate his theory on invisible aircraft. Covered with a transparent plastic sheeting and with interior structure and opaque parts painted silver, the PS was found to be very difficult to see at first, but accumulation of dirt and the sheeting turning opaque diminished the effect fairly rapidly.

AIR-8

Military liaison variant with a 85 hp Siemens engine, fitted with a constant chord wing with greater area. One AIR-8 was built.

Specifications (AIR-3)

External links

• Yakovlev AIR-3