The Scaled Composites Model 133-4.62 ATTT, or Advanced Technology Tactical Transport was a technology demonstration project built by

Burt Rutan Elbert Leander "Burt" Rutan (; born June 17, 1943) is a retired American aerospace engineer and entrepreneur noted for his originality in designing light, strong, unusual-looking, and energy-efficient air and space craft. He designed the recor ...

Scaled Composites Scaled Composites (often called simply Scaled) is an American aerospace company founded by Burt Rutan and currently owned by Northrop Grumman. It is located at the Mojave Air and Space Port in Mojave, California, United States. Founded to d ...

in 1986 under contract to

DARPA The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Adva ...

Design and development

In the mid-1980s, the American government agency

, developed a concept for a

tandem wing QAC Quickie Q2 A tandem wing is a wing configuration in which a flying craft or animal has two or more sets of wings set one behind another. All the wings contribute to lift. The tandem wing is distinct from the biplane in which the wings are ...

STOL A short takeoff and landing (STOL) aircraft is a fixed-wing aircraft that can takeoff/land on short runways. Many STOL-designed aircraft can operate on airstrips with harsh conditions (such as high altitude or ice). STOL aircraft, including tho ...

transport, intended to act as a technology demonstrator and to meet a requirement for a long-range high-speed transport for US special forces, intended to fill the gap between helicopters and larger transport aircraft such as the

C-130 Hercules The Lockheed C-130 Hercules is an American four-engine turboprop military transport aircraft designed and built by Lockheed Corporation, Lockheed (now Lockheed Martin). Capable of using unprepared runways for takeoffs and landings, the C-130 w ...

. In 1986, DARPA placed a contract with

, a company set up by

and owned by

Beechcraft Beechcraft is an American brand of civil aviation and Military aircraft, military aircraft owned by Textron Aviation since 2014, headquartered in Wichita, Kansas. Originally, it was a brand of Beech Aircraft Corporation, an American manufacture ...

to build prototypes for advanced aircraft, for a 62% scale proof-of-concept demonstrator for the concept, called the Advanced Technology Tactical Transport (shortened to ATTT or AT³).North ''Aviation Week & Space Technology'' October 13, 1986, pp. 28–29.''Flight International'' January 30, 1988, p. 9. The ATTT had high-

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 ...

tandem wings, joined by long

nacelle A nacelle ( ) is a streamlined container for aircraft parts such as Aircraft engine, engines, fuel or equipment. When attached entirely outside the airframe, it is sometimes called a pod, in which case it is attached with a Hardpoint#Pylon, pylo ...

s which carried the aircraft's

tractor configuration In aviation, a tractor configuration is a propeller-driven fixed-wing aircraft with its engine mounted with the propeller in front, so that the aircraft is "pulled" through the air. This is the usual configuration; the pusher configuration ...

turboprop A turboprop is a Gas turbine, gas turbine engine that drives an aircraft Propeller (aeronautics), propeller. A turboprop consists of an intake, reduction drive, reduction gearbox, gas compressor, compressor, combustor, turbine, and a propellin ...

engines, large fuel tanks, and the main undercarriage units for the aircraft's retractable

tricycle landing gear Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', that is arranged in a tricycle fashion. The tricycle arrangement has one or more nose wheels in a single front undercarriage and two or more main wheels slightly aft of th ...

. As first built, it had a conventional, cruciform tail. A novel arrangement of eight fast acting

fowler flap A flap is a high-lift device used to reduce the stalling speed of an aircraft wing at a given weight. Flaps are usually mounted on the wing trailing edges of a fixed-wing aircraft. Flaps are used to reduce the take-off distance and the landin ...

s was fitted, inboard and outboard of the engines on each of the wings. These would be extended rearwards in a low-drag configuration prior to commencing the take-off run then quickly lowered to increase lift at the point of take-off. The aircraft was of

composite construction Composite construction is a generic term to describe any building construction involving multiple dissimilar materials. Composite construction is often used in building aircraft, watercraft, and building construction. There are several reasons to ...

, mainly

glassfibre Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass clo ...

and

carbon fibre Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers ( Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon comp ...

. It was powered by two

Pratt & Whitney Canada PT6 The Pratt & Whitney Canada PT6 is a turboprop aircraft engine produced by Pratt & Whitney Canada. Its design was started in 1958, it first ran in February 1960, first flew on 30 May 1961, entered service in 1964, and has been continuously upd ...

A-135 turboprops.Scott ''Aviation Week & Space Technology'' January 18, 1988, p. 26. The ATTT demonstrator made its

maiden flight The maiden flight, also known as first flight, of an aircraft is the first occasion on which it leaves the ground under its own power. The same term is also used for the first launch of rockets. In the early days of aviation it could be dange ...

on December 29, 1987 from

Mojave Airport The Mojave Air and Space Port at Rutan Field is in Mojave, California, United States, at an elevation of . It is the first facility to be licensed in the United States for horizontal launches of reusable spacecraft, being certified as a spa ...

, base of Scaled Composites.Scott ''Aviation Week & Space Technology'' September 4, 1989, p. 38. It completed its initial test program of 51 test flights, with a total of 112 flying hours, on November 8, 1988. It was then rebuilt with a revised tail, with a twin-boom configuration replacing the original single cruciform tail unit, with the fuselage shortened and a rear-loading ramp fitted. The revised layout improved handling, lowering minimum single-engine safety speed (which was previously significantly higher than the stall speed). A further 13 test flights were flown to evaluate the revised layout.''Flight International'' July 8, 1989, p. 16. The aircraft has been de-registered and is currently in storage at the Air Force Flight Test Center Museum at

Edwards Air Force Base Edwards Air Force Base (AFB) is a United States Air Force installation in California. Most of the base sits in Kern County, California, Kern County, but its eastern end is in San Bernardino County, California, San Bernardino County and a souther ...

Specifications (Final configuration)

References

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External links

Model 133 at Scaled Composites' website

{{Scaled Composites ATTT 1980s United States experimental aircraft Aircraft first flown in 1987 Tandem-wing aircraft High-wing aircraft ATTT Twin-boom aircraft Twin-turboprop tractor aircraft