The CVT4 Strale ( en, Arrow) was a one-off, experimental, high performance

glider Glider may refer to: Aircraft and transport Aircraft * Glider (aircraft), heavier-than-air aircraft primarily intended for unpowered flight ** Glider (sailplane), a rigid-winged glider aircraft with an undercarriage, used in the sport of glidin ...

designed and built in

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...

. Completed in 1961, it was a refined version of the earlier CVT2 Veltro.

Design and development

The Strale was a refinement of the pioneering CVT2 Veltro of 1954. The Veltro went from design commencement to completion in eight months; the Strale, started in 1955, was not finished until July 1961, even though the two aircraft had much in common. The main differences between the Veltro and the Strale were in the wing, even though these had a similar straight tapered plan and used the same

laminar flow In fluid dynamics, laminar flow is characterized by fluid particles following smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. At low velocities, the fluid tends to flow without lateral mi ...

NACA airfoil sections. The Starle's wing was constructed, like that of the Veltro, around a forward main box spar and a lighter secondary spar aft but was in two rather than three parts. The outer span washout and the tip bodies were discarded. The span was increased by , which raised the aspect ratio from 18 to 19.3. Each

aileron An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

of the Strale was shortened by and

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

covered, and the combined flaps/ airbrakes of the Veltro were discarded, replaced by

spoiler Spoiler is a security vulnerability on modern computer central processing units that use speculative execution. It exploits side-effects of speculative execution to improve the efficiency of Rowhammer and other related memory and cache attacks. Ac ...

s. These were similar to those used on the CVT M-100S: mounted immediately behind the main spar at about one third span, each set consisted of five plates that rotated about chordwise axes out of the wing, each plate projecting both above and below. The two sets rotated in opposite directions and proved to be very effective. The Strale was a

high wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

rather than

shoulder wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplane (aeronautics), multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowe ...

design, reducing aerodynamic interference over the upper surface. It had a slightly deeper

cockpit A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...

and a single wheeled version of the Veltro's trailing arm, retractable

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 ...

, the wheel with its single

shock absorber A shock absorber or damper is a mechanical or hydraulic device designed to absorb and damp shock impulses. It does this by converting the kinetic energy of the shock into another form of energy (typically heat) which is then dissipated. Most sh ...

now totally within the

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

after retraction. The slender rear fuselages and low

T-tail A T-tail is an empennage configuration in which the tailplane is mounted to the top of the fin. The arrangement looks like the capital letter T, hence the name. The T-tail differs from the standard configuration in which the tailplane is ...

s of the two gliders were very similar, though the

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

added after flight testing to the Veltro was more smoothly faired into the

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. Fin ...

of the Strale. The double slotted

rudder A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

was increased in area by about 11%, lowering its aspect ratio still further and making the overall fuselage length greater. The Strale made its first flight in July 1961 and after some testing took part in the Italian National Gliding Competition in

Perugia Perugia (, , ; lat, Perusia) is the capital city of Umbria in central Italy, crossed by the River Tiber, and of the province of Perugia. The city is located about north of Rome and southeast of Florence. It covers a high hilltop and part o ...

early that August. Like the Veltro, it was seen as an experimental aircraft and only one was built.

Specifications

References

{{Morelli aircraft 1960s Italian sailplanes Aircraft first flown in 1961