The Moskalyev SAM-9 (Arrow) was a one-off,

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

, 1930s

experimental An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs whe ...

tailless aircraft In aeronautics, a tailless aircraft is a fixed-wing aircraft with no other horizontal aerodynamic surface besides its main wing. It may still have a fuselage, vertical tail fin (vertical stabilizer), and/or vertical rudder. Theoretical advanta ...

designed to test the characteristics of a leaf-shaped low-aspect-ratio

delta wing A delta wing is a wing shaped in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta (letter), delta (Δ). Although long studied, the delta wing did not find significant practical applications unti ...

Design and development

As early as 1933, Aleksandr Moskalyev was designing a rocket-powered, tailless aircraft with a highly-swept short-span curved

with wingtip

fin A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. F ...

s and

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, airship, or other vehicle that moves through a fluid medium (usually air or water). On an airplane, the rudder is used primarily to counter adverse yaw ...

s, able to fly faster than sound. Because no sufficiently powerful engines were available at the time, the Moskalyev SAM-4 Sigma was never built but it led to two interim types, the SAM-7 Sigma and SAM-9 Strela. The tailless Strela was built to test the behaviour of the SAM-4's radically new wing plan using a highly swept

delta Delta commonly refers to: * Delta (letter) (Δ or δ), the fourth letter of the Greek alphabet * D (NATO phonetic alphabet: "Delta"), the fourth letter in the Latin alphabet * River delta, at a river mouth * Delta Air Lines, a major US carrier ...

with moderately convex

leading In typography, leading ( ) is the space between adjacent lines of type; the exact definition varies. In hand typesetting, leading is the thin strips of lead (or aluminium) that were inserted between lines of type in the composing stick to incre ...

and trailing edges. Set at

shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder m ...

height, the

wing root The wing root is the part of the wing on a fixed-wing aircraft or winged-spaceship that is closest to the fuselage,Peppler, I.L.: ''From The Ground Up'', page 9. Aviation Publishers Co. Limited, Ottawa Ontario, Twenty Seventh Revised Edition, 1 ...

ran from ahead of the engine to the extreme tail and was fitted with broad- chord

elevon Elevons or tailerons are aircraft control surfaces that combine the functions of the elevator (used for pitch control) and the aileron (used for roll control), hence the name. They are frequently used on tailless aircraft such as flying wings. ...

s equipped with

trim tab Trim tabs are small surfaces connected to the trailing edge of a larger Flight control surfaces, control surface on a boat or aircraft, used to control the trim of the controls, i.e. to counteract hydro- or aerodynamic forces and stabilise the ...

s. It had the unusually low

aspect ratio The aspect ratio of a geometry, geometric shape is the ratio of its sizes in different dimensions. For example, the aspect ratio of a rectangle is the ratio of its longer side to its shorter side—the ratio of width to height, when the rectangl ...

of 0.925. Like the rest of the Strela, the wing structure was wood. Control surfaces were fabric covered but the rest of the Strela's skin was

plywood Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboa ...

. Moskalyev had intended to use a

Hispano-Suiza 12Y The Hispano-Suiza 12Y was an aircraft engine produced by Hispano-Suiza for the French Air Force before the Second World War. The 12Y became the primary French 1,000 hp (750 kW) class engine and was used in a number of famous aircraft ...

engine, but only a

Renault 6P The Renault 6P, also called the Renault Bengali, was a series of air-cooled 6-cylinder inverted in-line aero engines designed and built in France from the late 1920s, which produced from to . Design and development Charles Lindbergh's Atlantic ...

was available. The Strela's enclosed cockpit was at about mid-chord with a fairing behind it reaching the large, triangular fin with a narrow chord

equipped with a trim tab. The Strela had a fixed conventional

undercarriage Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include: *The landing gear of an aircraft. *The ch ...

, with

cantilever A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...

faired legs based on those of the Moskalyev SAM-5 and a sprung tailskid. It was first flown, at

Voronezh Voronezh ( ; , ) is a city and the administrative centre of Voronezh Oblast in southwestern Russia straddling the Voronezh River, located from where it flows into the Don River. The city sits on the Southeastern Railway, which connects wes ...

, in early 1937 by A.N.Rybo. A.N.Gusarov and A.P.Chernavskii explored its characteristics over the next few months, finding it controllable but demanding. The high landing

angle of attack In fluid dynamics, angle of attack (AOA, α, or \alpha) is the angle between a Airfoil#Airfoil terminology, reference line on a body (often the chord (aircraft), chord line of an airfoil) and the vector (geometry), vector representing the relat ...

(around 20°) typical of delta wing aircraft was not yet familiar but worrying. In mid-1937 development of the SAM-9 was ended.

Specifications

References

{{Moskalyev aircraft Moskalyev aircraft Tailless aircraft Single-engined tractor aircraft 1930s Soviet experimental aircraft Soviet inventions Russian inventions Aircraft first flown in 1937 Mid-wing aircraft Aircraft with fixed conventional landing gear