Yakovlev AIR-4
| Company type | Aircraft |
|---|---|
| Industry | Aviation |
| Founded | 1929 |
| Founder | Aleksandr Sergeyevich Yakovlev |
| Headquarters | Soviet Union |
| Products | General aviation monoplanes |
The Yakovlev AIR-3 was a Soviet two-seat general aviation monoplane from the late 1920s, designed and constructed by Aleksandr Sergeyevich Yakovlev.[1]
Development
After creating the earlier AIR-1 and AIR-2 models, Yakovlev enrolled at the Zhukovsky Air Force Engineering Academy (Nikolai Zhukovsky Air Force Engineering Academy), where he developed the AIR-3. This aircraft featured a strut-supported high parasol wing, resembling the previous AIR-2 biplane.[2] The powerplant was a 60 horsepower (45 kW) Walter NZ-60 radial piston engine.[1] The plane was also nicknamed Pionerskaya Pravda, named after the young communist newspaper that financed its construction through reader contributions.[2] On 6 September 1929, the AIR-3 completed a nonstop flight covering 1835 km between Mineralnye Vody and Moscow, setting two world records for light aircraft.[1][3]
In 1930, the design evolved into the Yakovlev AIR-4, which incorporated a redesigned split-axle landing gear, expanded cockpits with access doors, and increased fuel capacity.[3]
One example of the AIR-4 was adapted in 1933 as the Yakovlev AIR-4MK to evaluate nearly full-span split flaps. To maximize flap area, floating wingtips were introduced to provide roll control.[3]
Additionally, a military liaison version called the Yakovlev AIR-8 was produced in 1934. This variant featured an 85 horsepower (63 kW) Siemens engine and constant chord wings with a larger surface area.[3]
Kozlov PS
In 1935, following initial trials with a Polikarpov U-2, Professor Sergei Grigorevich Kozlov from the Nikolai Zhukovsky Air Force Engineering Academy adapted a Yakovlev AIR-4 to create the Kozlov PS (Prozrachnyy Samolyot — transparent aircraft). The traditional fabric covering on the wings and fuselage was substituted with a clear plastic material known as ''Cellon'' or ''Rhodoid''. Additionally, the solid structural components were coated with a white paint blended with aluminium powder. Both ground-based and airborne tests validated Kozlov’s hypotheses, also providing the crew with exceptional visibility. Despite the initial promising results, the transparent film eventually became clouded due to dirt accumulation and sun exposure, which significantly reduced the ''invisibility effect''.[2][4]
Kozlov envisioned a single-seat reconnaissance plane utilizing this transparent plastic covering, but concerns over the material's structural integrity prevented further development. Subsequent investigations into transparent aircraft were conducted by the experimental institute led by Pyotr I. Grokhovskii, yet no additional planes employing Kozlov’s transparency techniques were produced.[2][4]
AIR-3
- A two-seater monoplane powered by a 60 hp (45 kW) Walter NZ-60 radial piston engine, derived from the Yakovlev AIR-2. Only a single AIR-3 was constructed.[2]
AIR-4
- An enhanced model featuring increased fuel capacity and revised landing gear design. At least five units of the AIR-4 were manufactured.[2]
AIR-4MK
- (MK – Mekhanizeerovannoye Krylo, meaning mechanized wings). To investigate high-lift devices for approach control, one AIR-4 (registration CCCP-E-31) was modified with full-span split flaps and floating wingtips that rotated about transverse axes to manage roll.[2]
E-31
- This designation corresponds to the AIR-4MK based on its registration number.[2]
Kozlov PS
- Sergei G. Kozlov converted a single AIR-4 to demonstrate his concept of low-visibility aircraft, effectively creating an early form of stealth aircraft. The plane was covered in transparent plastic sheeting, while its internal framework and opaque sections were painted silver. Initially, the aircraft was extremely difficult to detect; however, over time, dirt buildup and opacity of the covering diminished this effect significantly.[2][4]
AIR-8
- A military liaison version equipped with an 85 hp (63 kW) Siemens engine and featuring a constant-chord wing with increased surface area. Only one AIR-8 was produced.[2]
Specifications (AIR-3)
References
- ↑ 1.0 1.1 1.2 "Part Work 1982–1985". The Illustrated Encyclopedia of Aircraft. Orbis Publishing. 1985. p. 3098.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 Cite error: Invalid
<ref>tag; no text was provided for refs namedOKB Yak - ↑ 3.0 3.1 3.2 3.3 Nemecek, Vaclav (1986). The History of Soviet Aircraft from 1918. London: Willow Books. p. 245. ISBN 0-00-218033-2.
- ↑ 4.0 4.1 4.2 Cite error: Invalid
<ref>tag; no text was provided for refs namedSov X
External links
