John Carver Meadows Frost

Frost began his aeronautical career in the 1930s as an apprentice for Airspeed Limited before he moved on to the Miles, Westland, Blackburn and Slingsby companies. In 1937, Frost had designed the fuselage of the new Westland Whirlwind fighter. At Blackburn, he had been involved with the design and construction of their pre-war wind tunnel. While working for Slingsby Sailplanes from 1939 to 1942, he met his future wife, Joan, who had worked in the Slingsby Design Office as a technical artist. Frost designed the Slingsby Hengist, a troop-carrying glider to be used for the Normandy landings. It was not a success and only a few were built but it included an ingenious innovation: the use of a rubber bag undercarriage.

Frost's work began to be noticed when he joined the de Havilland Aircraft Company (UK), builders of the famed Mosquito bomber and fighter. After joining the de Havilland firm in 1942, Frost had become one of the senior members of the design team working on the Hornet fighter, based on the Mosquito, for which he designed a unique flap design. Later, as one of the team of designers on the D.H.100 Vampire, he was responsible for the design of the original flaps, dive brakes and ailerons for this fighter. The Vampire was the second British jet fighter designed in the Second World War, but other than its powerplant and plywood construction patterned on the Mosquito, the diminutive fighter was mainly conventional in design.

The first DH. 108 built – TG283. The torpedo-shaped objects on the wing tips are containers for anti-spin parachutes

Frost had then become heavily involved in one of the most important new developments at the time: swept wings and a tailless configuration on a supersonic jet fighter. Designer and company founder, Sir Geoffrey de Havilland, had already begun the D.H.106 Comet development process and was considering that radical configuration for their first jet airliner. As Project Engineer on the D.H.108, with only a team of 8–10 draughtsmen and engineers, Frost created a remarkable aircraft by marrying the front fuselage of the de Havilland Vampire to a swept wing and short stubby vertical tail to make the first British swept wing jet, soon to be unofficially known as the "Swallow." The elegant and sleek experimental D.H.108 was also to serve as a test "mule" to investigate stability and control problems for the new Comet airliner.

The D.H.108 first flew on 15 May 1946, a mere eight months after Frost had a go-ahead on the project. Company test pilot and son of the builder, Geoffrey de Havilland Jr., flew the first of three aircraft and found it extremely fast – fast enough to try for a world speed record. On 12 April 1948, a D.H.108 did set a world's speed record at 973.65 km/h (605 mph) and later on became the first jet aircraft to exceed the speed of sound. The first D.H.108, TG-283, was alleged to have suddenly jumped from Mach .98 to Mach 1.05 while being test-flown by John Derry on 9 September 1948. On 27 September 1946, while practising for an upcoming run at a new speed record, Geoffrey de Havilland Jr. died when his D.H.108 broke up in the air at or near the speed of sound.

On 14 June 1947, Frost arrived at Avro Canada's Malton, Ontario facility with his wife to take over as Project Designer of the new XC-100 jet fighter interceptor. After 18 months of development, the fighter had entered the mock-up stage. Frost decided to alter the aircraft design which immediately brought him into conflict with Avro Canada Chief Aerodynamacist Jim Chamberlin. Basically "cleaning up" the fuselage, Frost set out to change the design subtly. Even though he wanted to use a swept-wing configuration, the prototype (by now called the CF-100 Canuck) proceeded to prototype stage in the same basic configuration of straight-winged, twin-engined form. (The swept-wing CF-103 proposed by Frost in December 1950 was a transonic follow-up to the CF-100). Although the CF-100 prototype was now a much more sleek shape, Frost still considered the design awkward. "It was a clumsy thing. All brute force," he remarked.[1]

While Frost was in England to confer with members of the Hawker Siddeley Group, Chamberlin made another alteration by moving the engines back and "notching" the wing spar to accommodate the change. The weakened spar was a flexible structure where the stress was heavy leading to potentially dangerous situations with the CF-100.

A CF-100 Mk.3 painted as the CF-100 prototype, on display at the Calgary AeroSpace Museum.

Gloster's Chief Test pilot Bill Waterton flew with Frost in the second seat; to the test pilot, this was a revelation: "(Frost was)...very much the keen English public schoolboy type. Here was another delightful contrast to England, where I was never able to find a designer with spare time enough to fly in his own creation."[2] Frost considered it important to get a feel for the aircraft and its systems. He even tested the CF-100's ejection seat by becoming a test subject himself. Early flights revealed the great potential of the aircraft but also showed the flaw in the spar was dangerous. With the crash of the second CF-100 prototype and early production CF-100s delivered to the RCAF without the final modifications to the spar, Frost was blamed for the delays and removed as CF-100 Project Designer in early 1952.

Frost made a proposal that Avro start an experimental project based on vertical takeoff and landing concepts. "It was not a case of Frost indulging in a personal whim. The idea of a saucer-like flying machine had revolutionary implications then and still does. A conventional aircraft is very inefficient, aerodynamically. Like a bumble bee, there's no way it should fly. It only does so because of the wing which gives it lift and the engine's power to overcome the drag of the fuselage, the load, the tailplane, the stabilizers, fins and the engines."[3]

Shortly after its formation in 1952, Frost's Special Projects Group started a paper study on a "pancake" engine, a jet turbine that had its main components arranged in a circular design. From the outset, the Special Projects Group had a cloak-and-dagger feel to it. Housed in a Second World War-era structure, across from the company headquarters, the group had all the accoutrements of a top-secret operation, including security guards, locked doors and special pass cards. Within the confines of this technical fortress, Frost surrounded himself with a collection of like-minded dreamers and maverick engineers. There he encouraged close cooperation and, while ostensibly the boss, he was collegial and very much one of the boys.

Project Y mock-up c.1954.

Research undertaken by Frost on the "Coandă effect" confirmed that the concept of ground cushion could be the basis for a vehicle he had envisioned that could have both vertical take-off and landing (VTOL) capabilities and could still operate as a high-performance aircraft. As Frost developed further studies, his ideas on revolutionary vertical takeoff systems led to the patent of "Aircraft Propulsion and Control".[4]

In 1952, "Project Y", a "spade-shaped" fighter powered by Frost's revolutionary pancake engine proceeded to mock-up stage. By 1953, with the company having little more than a wooden mock-up, paper drawings and promises to show for a $4-million (Cdn) outlay, a more critical eye was cast on the project. Not surprisingly, the plug got pulled when government funding from the Defence Research Board dried up.

The Avro VZ-9-AV Avrocar.

Frost's later ideas revolved around a disk or saucer shape – a "flying saucer" and resulted in a number of patents in Great Britain, the United States and Canada on the unique concepts of propulsion, control and stabilisation systems that were incorporated. Frost continued to lobby for the project now called the "Y-2" and achieved a remarkable breakthrough by demonstrating the project to the United States Air Force. With funding from the Americans, Frost was able to proceed with his research. From 1955 to 1959, the design team concentrated on the new VTOL supersonic studies known as Weapon Systems 606A which Avro Canada continued to support through an associated private venture program, the PV-704 which resulted in the construction of an engine test rig in 1957.

The PV-704 supersonic test model, powered by six Armstrong-Siddeley Viper jet engines driving a central rotor, was built and housed inside a small, brick testing rig. The test model was abandoned in favour of a simpler flying model led to the only design that materialised from the Avro Special Project Group, a "proof-of-concept" vehicle, the VZ-9-AV "Avrocar". Two Avrocar prototypes were constructed and completed a series of wind tunnel tests at NASA Ames in California and a 75-hour flying program at the Malton home of Avro Canada. The results of the testing revealed a stability problem and degraded performance due to turbo-rotor tolerances. Before modifications could be achieved, funding ran out with the final flight test program completed in March 1961.

As the result of his work in vertical takeoff systems, John Frost was invited to become a fellow of the Canadian Aeronautics and Space Institute after he presented the W. Rupert Turnbull seventh lecture on 25 May 1961. The citation noted that Frost had discovered and patented the air cushion effect that had been evident in his work on flying saucers and that U.S. Patent #3124323 "Aircraft Propulsion and Control" was one of a series of US, Canadian and British patents to become known as the "Frost patents."