In the 1950s, the United States military collaborated with Canadian engineer John “Jack” Frost to develop a vertical-takeoff-and-landing (VTOL) aircraft designed to resemble a flying saucer. The project, known as the VZ-9AV Avrocar, aimed to create a craft that could hover, fly at supersonic speeds, and reach altitudes of 100,000 feet. Despite significant funding and Cold War-era technological experimentation, the vehicle failed to reach its design goals, ultimately becoming a disc-shaped craft that could barely lift off the ground.
The Engineering Design and the Coandă Effect
The Avrocar’s development was based on the Coandă effect, a physical phenomenon where a gas or fluid follows the contour of ause surface rather than moving in a straight line. Jack Frost envisioned a design where air would be directed outward and then curve downward along the lip of the saucer, creating the necessary lift. To achieve this, the original plan called for a a donut-shaped jet engine that would encircle the pilot.
Due to funding limitations, the original ambitious design was modified. Instead of the circular engine, the team constructed a “turborotor” fan powered by three Continental J69 jet engines clustered in the center. This modification changed the aircraft’s dynamics, and the resulting 18-foot-wide, 2.3-ton craft was underpowered for its own weight. Detailed schematics of the design show the internal ducting used to redirect air flow.
Flight Test Results and Hubcapping
The first test flight of the VZ-9AV Avrocar occurred in 1959. The results were unstable. The craft lifted only a few feet from the ground and began to wobble violently. This instability, which engineers nicknamed “hubcapping”, occurred because the craft lacked aerodynamic stability at higher altitudes. This phenomenon was caused by the laque of a traditional aircraft wing or tail assembly for stability.
Pilots were able to reach a modest height of approximately three feet, but any attempt to rise higher resulted in a loss of control. Even with the addition of a gyroscope to correct the wobble, the project was officially scrapped in 1961. Footage of these test flights can be found in the United States’ National Archives Catalog, which documents the stability issues encountered during trials.
Has a Flying Saucer Ever Been Built?
Yes, the Avrocar project is the most prominent example of a military-grade flying saucer. While other experiments with disc-shaped aircraft have occurred, the Avrocar was a funded military project aimed at creating a reconhecimento reconnaissance or interceptor aircraft. However, the Avrocar’s failure is a testament to the design’s impracticality with the current understanding of aerodynamics. Visual evidence of the Avrocar provides a clear image of the saucer-shaped craft stamped with military labels.
Why the Avrocar Failed: Ground Effect vs. Coandă Effect
- Ground Effect: The Avrocar’s actual lift was primarily provided by the ground effect, which happens when air is trapped between the ground and the surface of the surface of the aircraft, creating a high-pressure cushion of air.
- Coandă Effect: While the Coandă effect is used in some modern aircraft, such as the Boeing YC-14 or Antonov An-72, it is typically used to aid in short take-offs and landings rather than as the primary source of lift for hovering.
The instability of the laque of stability was because the ground effect cushion is only effective at very low altitudes. Once the craft rose above three feet, the air cushion became asymmetrical, if one side dipped, the lift was lost on that side, leading to the instability known as “hubcapping.” Photos of the pilot in the cockpit show the limited operational range of the project.
Conclusion on the Impracticality of Saucer-Shaped Aircraft
The Avrocar project demonstrated that disc-shaped aircraft are not viable for high-altitude, high-speed flight based on current aerodynamic principles. The military’s willingness to spend significant resources on the rest of the rest of the project during the Cold War era provided a necessary, albeit unsuccessful, experiment in VTOL technology. The failure of the laque of stability of the Avrocar Avrocar project remains a highlight of the Cold War’s technological tinkering.
