Overview
The Avro Canada VZ-9 Avrocar was a vertical takeoff and landing (VTOL) experimental aircraft developed by A.V. Roe Canada (Avro Canada) in the late 1950s. It was a disc-shaped vehicle that used the Coandă effect to generate lift from a central turboshaft-driven fan, exhausting air over the upper surface of the disc. The project was funded jointly by the US Army and US Air Force under the code name Project 1794, with the initial goal of developing a supersonic flying saucer.
The Avrocar is one of the most visually distinctive experimental aircraft ever built — it literally looked like a flying saucer. However, its performance fell far short of expectations. The aircraft could barely hover a few feet off the ground and could not exceed approximately 35 mph in forward flight. The programme was cancelled in 1961 after the construction of two prototypes.
Design and Technology
The Avrocar's propulsion system was based on the Coandă effect — the tendency of a fluid jet to stay attached to a nearby curved surface. The aircraft was powered by three Continental J69 turbojet engines driving a central fan. The fan's exhaust was directed over the upper surface of the disc, creating a low-pressure zone above the aircraft that generated lift. For forward flight, the exhaust could be deflected rearward through adjustable nozzles at the disc's trailing edge.
The aircraft had a diameter of 18 feet (5.5 m) and a height of approximately 3 feet (0.9 m) at the rim. It was designed to carry a pilot and one observer in a central cockpit bubble. The intended performance was a top speed of 300 mph (480 km/h) and a service ceiling of 10,000 feet (3,000 m) — but these targets were never remotely approached.
The Avrocar suffered from a fundamental aerodynamic problem: the Coandă-effect lift system worked adequately in ground effect (within a few feet of the surface) but lost effectiveness rapidly with altitude. The aircraft could not fly higher than approximately 3 feet (0.9 m) in hover, and the thrust available for forward flight was insufficient to achieve the speeds needed for the disc to generate aerodynamic lift.
Development History
The Avrocar programme originated in the early 1950s when John Frost, a British-born engineer at Avro Canada, began investigating disc-shaped VTOL aircraft. Frost's initial concept was a radical supersonic interceptor called the Avro Ace (or Project Y), which used a disc-shaped lifting body with jet thrust directed through nozzles around the rim.
In 1953, Avro Canada approached the US military with the concept. The US Air Force, interested in a potential supersonic VTOL fighter, funded a feasibility study under the designation Project 1794 (also known as Weapon System 606A). The study concluded that a disc-shaped aircraft could theoretically achieve supersonic speeds, and the Air Force funded further development.
In 1955, the US Army Transportation Corps joined the programme, interested in a smaller, subsonic "flying jeep" — a simple, rugged VTOL vehicle that could operate from any terrain. The Army's interest was more practical and less technically ambitious than the Air Force's supersonic interceptor vision.
The first Avrocar prototype (serial 58-7055) was completed in 1958 and began ground testing at Avro Canada's Malton (Toronto) facility. The second prototype (serial 58-7056) followed shortly after.
Testing and Performance Limitations
The first Avrocar tethered flight occurred on 12 November 1958. Free flight testing began in 1959. The results were deeply disappointing:
- The aircraft could only hover to a height of about 3 feet (0.9 m) — the ground effect limit of the Coandă-effect lift system.
- Forward flight speed was limited to about 35 mph (56 km/h) — far below the 300 mph target.
- The aircraft was unstable in forward flight, exhibiting a pitching oscillation that the control system could not adequately suppress.
- Engine performance was marginal, and the aircraft was severely underpowered.
Testing continued at NASA Ames Research Center in Moffett Field, California, where the second prototype was tested in the 40x80 foot wind tunnel. The wind tunnel data confirmed the fundamental aerodynamic limitations of the design and showed that the Coandă-effect lift system could not be scaled to the performance levels required by either the Air Force's interceptor vision or the Army's flying-jeep requirement.
Project Cancellation and Legacy
The Avrocar programme was cancelled in 1961. The two prototypes were placed in storage and eventually transferred to museums. The first prototype is on display at the National Museum of the United States Air Force (Dayton, Ohio). The second is at the Fort Eustis Military Transportation Museum (Virginia).
The Avrocar's legacy is primarily as a cautionary tale about the gap between theoretical aerodynamic concepts and practical engineering. The Coandă-effect VTOL concept was not inherently flawed — it was simply not scalable to the performance levels required. The programme also demonstrated the difficulty of developing VTOL aircraft that could transition efficiently from hover to forward flight, a challenge that would not be fully solved until the development of the Harrier and later the F-35B.
The Avrocar also contributed to the mythology of "flying saucers" in the 1950s and 1960s. The sight of a disc-shaped aircraft being tested at Avro Canada's facility fuelled UFO reports, and the programme's existence was not widely known until years after its cancellation.
Specifications
| Parameter | Value | |---|---| | Role | VTOL experimental aircraft | | Manufacturer | Avro Canada | | First flight | 12 November 1958 (tethered) | | Number built | 2 | | Crew | 1 (plus 1 observer) | | Diameter | 18 ft (5.5 m) | | Height | ~3 ft (0.9 m) at rim | | Empty weight | ~5,650 lb (2,560 kg) | | Max takeoff weight | ~7,500 lb (3,400 kg) | | Engines | 3 × Continental J69 turbojet (driving central fan) | | Max speed achieved | ~35 mph (56 km/h) | | Max hover height | ~3 ft (0.9 m) | | Programme | 1953–1961 | | Status | Cancelled |
Declassification and Provenance
The Avrocar programme was unclassified from its inception — it was a joint US-Canadian military research project, not a CIA programme. The aircraft were publicly displayed and tested, and the programme's cancellation was publicly reported.
The gallery image associated with this technology is from a legacy image compilation whose CIA-P2 catalog number is a legacy identifier and does not establish CIA authorship, declassification, or provenance for this specific photograph. The image appears to show an Avrocar in ground testing, consistent with publicly available photographs of the programme.
References
- Zuk, Bill. Avrocar: Canada's Flying Saucer. XYZ Publishing.
- Whitcomb, Randall. Avro Aircraft and Cold War Aviation. Canav Press.
- National Museum of the United States Air Force. "Avro VZ-9AV Avrocar." Museum exhibit.
- Winchester, Jim. The World's Worst Aircraft. Amber Books.
- Rogers, Mike. VTOL: Military Research Aircraft. Orion Books.