| Kharkiv KhAI-3 | |
|---|---|
 | |
| Role | motor glider transport |
| National origin | USSR |
| Manufacturer | Kharkovskii Aviatsionni Institut |
| Designer | Alexandr Alekseyevich Lazerev |
| First flight | 14 September 1936 |
| Number built | 1 |
The Kharkiv KhAI-3 or Aviavnito-3 was one of several Soviet mid-1930s motor glider transports intended to reduce transport costs.
Alexandr Alekseyevich Lazerev, who led the Kharkiv KhAI-3 Avianvito design team, already knew some of the problems posed by tailless aircraft. He was on the team which designed the almost uncontrollable KhAI-4 two years before (the Institute's designs did not always appear in their numerical order). That aircraft made only three flights before being grounded as dangerous. [1]
The much larger KhAI-3 was intended to show that low-powered aircraft could carry a useful eleven-passenger load with an engine producing just over 100 hp (75 kW). [1]
It was a tailless aircraft with a broad-chord wing and with a tractor engine, fin and rudder all on the centreline. Though there were initial thoughts of mounting the KhAI-3's Shvetsov M-11 five cylinder radial engine on a pylon over the wing, it was finally placed ahead of the leading edge on steel tubes from the front wing spar and fed from four tanks in the central wing. There was a long, six seat cabin on either side of the centreline with the pilot in the forward portside seat. The large, triangular fin mounted a broad, round-topped rudder. [1]
Its central wing panel was rectangular in plan, with a steel tube structure including four spars and dural skinning. It had a chord of 5.0 m (16 ft 5 in) and a chord/thickness ratio of 14%. The outer panels, 82% of the span, were all-wood structures with dihedral and sweep on the leading edge only, giving an overall sweep of 16° at quarter-chord;. They decreased in thickness outwards from 14% to 7%, with 8° washout. Each wing carried three control surfaces. Near each tip, close behind and parallel to the leading edge there was a large, rectangular plan interceptor. These were operated differentially by pedals which also controlled the rudder and were used to make flat turns. Inboard of the interceptors, each outer panel trailing edge carried two broad-chord control surfaces that acted as both ailerons and elevators. [1]
The Kharkiv KhAI-3 had a fixed, tailwheel undercarriage. Its forward-mounted engine and propeller allowed a short tailwheel to provide a ground angle of attack of 15°, avoiding one of the problems encountered with the KhAI-4. [1]
It was named after Sergei Kirov.[ citation needed ]
The first flight was made on 14 September 1936. On this occasion the front seats of both cabins were equipped with dual controls; the pilots were V. A. Borodin and E. I. Schwartz. During this and subsequent flights, controlled turns proved difficult however the various control surfaces were combined. A long development programme yielded significant improvements. [1]
The 1937 Aviavnito-8 was a proposed but unflown development with the same passenger capacity, dimensions and engine. [1]
Data fromRussian Aircraft 1875-1995 [1]
General characteristics
Performance
The Kharkiv KhAI-5, was a Soviet reconnaissance and light bomber aircraft, designed in the mid-1930s in the Kharkiv Aviation Institute, under the direction of Iosif Grigorevich Nyeman.
The General Aircraft GAL.56 was a family of 1940s British experimental tailless swept wing glider designs.
The Fairey S.9/30 was a two-seat, single-engined biplane built to meet an Air Ministry specification for a fleet reconnaissance aircraft. It flew during 1934–36 in both land- and seaplane configurations. Although only one was built, it was the progenitor of the Fairey Swordfish.
The Gwinn Aircar was a single-engined biplane with a cabin for two, designed in the US as a safe and simple private aircraft. Lacking a rudder, it had several unusual control features as well as an early tricycle undercarriage. Development was abandoned after a crash in 1938.
The Alpaero Choucas is a French two seat, single engine tailless kit-built ultralight motor glider. At least 12 are flying, with more under construction.
The Nike PUL 9 is an Argentine experimental tailless aircraft powered by a Rotax 447 engine.
The Davis-Costin Condor was a conventional all-wood, tandem-seat sailplane built in the United Kingdom in the 1950s. Only one was constructed; it was later rebuilt with a longer fuselage and other detailed alterations as the Condor 2.
The Akaflieg Braunschweig SB-13 Arcus was an experimental tailless, single seat, Standard Class glider designed and built in Germany in the early 1990s. Though it performed as well as its conventional contemporaries, it did not offer sufficiently improved performance to compensate for its difficult handling characteristics.
The Gribovsky G-20 was an aerobatic trainer, designed in the USSR in the mid-1930s. Only one was built; re-engined in 1937, it was used to train many aerobatic pilots.
The Gribovsky G-15 was a single engine, side-by-side two seat touring aircraft built in USSR in the 1930s. Only one was completed.
The Gribovsky G-27 was a light, economical, twin engined, multi-role aircraft built in the USSR in 1938-9. It did not reach production.
The Buscaylet-de Monge 7-4 was a small, French, twin-boom aircraft without a fuselage, built in the mid-1920s to explore the characteristics of a proposed larger machine.
The RRG Storch V was the only member of Alexander Lippisch's Storch series of tailless aircraft to be powered. It flew successfully in the year 1929.
The Bodiansky 20, a French four-seat touring aircraft flown in the early 1930s, was one of the first French aircraft to adopt Handley Page slots to delay the stall and lower landing speed.
The S.A.B.C.A. S.XII or S.A.B.C.A S.12 was a four-passenger light transport aircraft with three engines and a high wing, built in Belgium in the early 1930s.
The Invincible D-D was a prototype three/four seat touring aircraft, built in the US in 1929. One example flew but development was ended by the Great Depression.
The Kharkiv KhAI-4 was an experimental Soviet tailless aircraft tested in 1934. It only made three flights before being grounded as dangerous.
The RRG Delta I was a German experimental tailless aircraft flown in the early 1930s first as a glider and then powered. It was one of the first delta wing aircraft.
The Moskalyev SAM-7 Sigma was a one-off, Soviet, experimental tailless fighter aircraft.
The Gee Bee Model A was an American two-seat open cockpit single-bay biplane developed by the Granville Brothers that first flew in 1929.