The Avro Avrocar vertical take-off and landing (VTOL) aircraft designed by Avro of Canada for the U.S. military. The project was originally intended as a highly capable fighter aircraft, but the project proved to be complex. The goals of the Avrocar project reportedly changed names, and hands several times, eventually being abandoned by the U.S. Air Force, and ultimately the U.S. Army as well. 

VTOL aircraft were an industry obsession following World War Two. Unlike conventional aircraft, which needed runways to get up to speed prior to takeoff, VTOL aircraft would be able to take off vertically, eliminated the need for runways and runway infrastructure. There were two applicable scenarios for VTOL aircraft. 

During the Pacific Campaign during World War Two, carriers had more than proved their worth by launching hundreds of planes into the skies from their flight decks. But if a plane could take off vertically rather than needing a long flight deck, then carriers could potentially carry many more airframes. 

The other advantage that military planners envisioned was on land. In the early days of the Cold War, it was assumed that the opening salvos of the next war would target airports and other related infrastructure, destroying air forces and the runways needed to get planes into the air. If an airplane could be separated from needing a runway, then planes could be more widely dispersed and less of a target. Additionally, if a country’s airports were destroyed, they would not need to be rebuilt if a plane could take off elsewhere. 

Flying Saucer

Avro’s project went through several iterations. The most mature design was essentially a disk, or doughnut-like airframe. The doughnut design strove to solve one of the more challenging problems of the early jet age: designing an aircraft that had acceptable subsonic, and supersonic performance. At subsonic speeds, lift is created by air flowing around the wings of a plane, whereas at supersonic speeds, lift is created by shockwaves that form along specific points on an airframe. 

The Avro took advantage of the Coandă effect, a complex fluid dynamic phenomenon. The center of the Avro was a specially-developed air intake for a jet engine that was virtually as wide as the entire Avro. Air would be sucked in through the center, and then blown outwards along the edges of the doughnut, creating lift. The design was promising, as not only would the Avro be a VTOL-capable aircraft, but it would also solve the subsonic-supersonic problem as well—if things went according to plan.

But the Avro had many teething problems. Though low-level flight (around 3 feet or lower) was stable and controllable, flying above that was unpredictable and dangerous. A number of modifications were installed that improved the flight characteristics, but performance did not come close to approaching supersonic speeds. The Avro also suffered from extremely loud engine noise. Being so close to the engine, pilots were also subjected to almost unbearably hot temperatures, reducing their combat effectiveness. 

Limited Run

Ultimately the Avro was done in by the Harrier family of jump jets, which were capable of VTOL operations, and could exceed Mach 1 speed. The other factor that killed the Avro was the change in strategic thinking that gradually began to believe a nuclear strike would not happen at the beginning of the next war in Europe. 

Though the Avro was unsuccessful, there have been claims that reports of flying saucers could have been either modified Avros with better flight characteristics or perhaps other projects related to the Avro’s development. Maybe...