Buzz
Throughout the Cold War, numerous projects aimed to create aircraft capable of vertical takeoff and landing. While the Hawker Harrier achieved success, many other designs did not meet expectations.
10. The XFY-1 Pogo
Project Hummingbird, an initiative exploring vertical takeoff and landing (VTOL) aircraft, was initiated by the US Navy and Air Force. The goal was to develop a multirole fighter capable of operating from naval vessels and providing fleet air defense. Two companies were contracted to construct a prototype each. Convair’s XFY-1 Pogo design emerged as one of the successful contenders, outperforming its counterpart.
The XFY-1 was an unconventional design. Positioned vertically as a “tail-sitter,” it rested on the edges of its cruciform wings, which were fitted with small, unbraked wheels. This limitation meant operations were restricted to windless conditions.
The aircraft’s unique feature was its rotating pilot seat, which adjusted based on the plane’s orientation—vertical for takeoff and landing, horizontal for flight. In emergencies, a rope system was provided for the pilot to descend safely. Landing and takeoff were perilous, requiring the pilot to maneuver while looking backward.
While the project demonstrated the feasibility of VTOL aircraft, significant challenges remained. In 1956, the navy discontinued the program after the aircraft required extensive repairs. By then, focus had shifted to faster jet-powered carrier aircraft, overshadowing the propeller-driven designs of Project Hummingbird.
9. The XFV-1 Salmon
Lockheed’s contribution to Project Hummingbird, the XFV-1, took a different approach to VTOL design. Unlike its counterpart, it relied on an X-tail configuration for ground support instead of cruciform wings.
The XFV-1 never achieved vertical takeoff or landing due to a critical setback: the military allocated the sole suitable engine to Convair for their XFY-1 project. Lockheed had to settle for a less capable engine, restricting the aircraft to horizontal takeoffs using improvised landing gear.
Had it been equipped with the right engine, the XFV-1 might have succeeded. However, by 1955, the navy lost interest in the project due to advancements in jet-powered carrier aircraft. Additionally, the tail-sitter design posed significant challenges for safe landings on moving ships. Lockheed’s project was ultimately terminated in 1955.
8. The X-13 Vertijet
During the 1950s, the US Air Force recognized that its airfields were highly susceptible to nuclear strikes. This led to the demand for an aircraft capable of operating independently of extensive infrastructure. Concurrently, the US Navy halted funding for its X-13 VTOL jet research.
With the navy having thoroughly explored jet-powered VTOL technology, it presented a prime opportunity for the air force. They assumed control of the X-13 project and commissioned two prototype X-13 Vertijets for evaluation.
Testing commenced in 1955. Initial horizontal takeoffs exposed significant control issues, which were later resolved. The first vertical takeoff took place in 1956, followed by adjustments enabling a seamless shift from vertical to horizontal flight that same year.
Despite the prototypes’ success, the project lacked military urgency or necessity. Consequently, the aircraft never reached mass production.
7. The Mirage III V
In response to NATO’s demand for a supersonic fighter capable of vertical takeoff and landing, Dassault Aviation modified their renowned Mirage III. The French government commissioned a prototype in 1961, which Dassault developed by overhauling the original Mirage III design.
To achieve vertical lift, Dassault integrated eight auxiliary jet engines into the fuselage. However, the added weight and drag from these engines limited the aircraft’s maximum speed to subsonic levels.
Managing nine engines proved highly challenging. The prototype experienced crashes in 1964 and again in 1965, the latter resulting in the death of a US Air Force pilot. Despite achieving a successful transition from vertical takeoff to horizontal flight in 1966, the aircraft remained notoriously difficult to control.
A second prototype, equipped with a more powerful engine, became the only VTOL aircraft to surpass twice the speed of sound. However, it also met with disaster in 1966. This crash led the French government to abandon the project entirely.
6. The XV-5 Vertifan
The XV-5 Vertifan emerged from a US Army initiative to develop surveillance aircraft for battlefield reconnaissance. In a surprising decision, General Electric, an engine manufacturer, won the contract, with Ryan Aeronautical handling the airframe construction.
The XV-5 featured an innovative design, incorporating lifting fans within the wings and a smaller fan in the nose. Two jet engines supplied both horizontal thrust and power to the lifting fans. Since the fans relied solely on air from the jet engines, the system was both durable and low-maintenance.
The first prototype was completed in 1964, followed by a second within a year. Tragedy struck in April 1965 when one aircraft crashed during a transition from hover to horizontal flight. Another crash occurred in 1966 under unusual circumstances: the pilot ejected and died, but the aircraft landed safely. The surviving prototype was redesigned into a larger model, which remained operational until 1971, though it never progressed beyond experimental testing.
5. The Bell X-14
The Bell X-14 was designed to test the feasibility of thrust vectoring, a unique VTOL technology. The program proved successful, with the aircraft in operation from the 1950s until its destruction in a crash during the 1980s.
Bell secured the contract from the US Air Force in 1955. Working under a tight budget, Bell constructed the aircraft in just three months, utilizing existing parts. The wings and some landing gear came from a light utility aircraft, while the tail was sourced from another. After several years of testing, the air force transferred the aircraft to NASA in 1959.
NASA upgraded the engines for increased thrust and employed the aircraft in various research initiatives until its crash in 1981. Notably, Neil Armstrong piloted it as part of his training for lunar landings.
4. The XFV-12A
The XFV-12A was the US Navy’s ambitious project to create a supersonic VTOL aircraft. This cutting-edge fighter employed an experimental and intricate thrust mechanism. To reduce costs, the prototype incorporated parts from existing fighter jets. Its canard wing design featured wings housing the vertical thrust system.
The aircraft’s innovative lift mechanism, known as “thrust augmenting,” channeled air from the jet engine through a network of ducts into the wings. The air exited through openings beneath the wings, generating the necessary lift.
Although small-scale model tests showed potential, full-scale trials were disappointing, especially when employing a high degree of thrust augmentation. Significant thrust losses due to air movement through the ducts prevented the aircraft from lifting off during prototype testing in 1974. The US Navy abandoned the project, canceling it in 1981.
3. The VZ-9V Avrocar
The VZ-9V Avrocar was the US military’s ambitious effort to create an authentic flying saucer. The design aimed to incorporate stealth features, achieve altitudes of up to 25,000 meters (80,000 ft), and reach speeds of 3,700 kilometers per hour (2,300 mph).
The challenge was immense. The VZ-9V, a subsonic prototype, served as a proof of concept. Featuring a central fan and dual cockpits on either side, it resembled a classic UFO.
The design encountered significant issues during test flights, particularly with stability and control. A US Air Force assessment highlighted the need for extensive modifications before the aircraft could achieve flight. By the time these changes were proposed, the US had lost interest, leading to the project’s termination.
2. The SNECMA Coleoptere
Developed in France during the mid-1950s, the SNECMA Coleoptere aimed to create a VTOL aircraft capable of surpassing the speed of sound. Its unique design featured a circular wing encircling the aircraft, intended to function as a ramjet in theory.
Initial tests with a smaller prototype faced challenges, including vibrations during vertical takeoff. These issues disappeared with a larger, manned model, but new problems arose, such as slow spinning during hover and difficulties in achieving precise landings.
On its ninth flight, the aircraft briefly attained horizontal flight, but only due to the pilot losing control. It ultimately crashed after spinning uncontrollably in the air. This led to the abandonment of further development.
1. The VZ-8 Airgeep
The Piaseki VZ-8 Airgeep, developed by the US Army as a prototype flying jeep, bore little resemblance to a traditional jeep. Instead, it featured an open cockpit design similar to a helicopter. Constructed in 1958, it was powered by two 400-horsepower engines, each driving a ducted fan propeller positioned at the front and rear of the vehicle.
An open cockpit was situated between the two propellers. Steering was achieved by adjusting the thrust of each propeller. Despite its unconventional appearance, which seemed neither agile nor secure, two prototypes were built, with the second model featuring a slightly curved fuselage to minimize aerodynamic drag.
Contrary to expectations, the VZ-8 Airgeep proved to be highly maneuverable and simple to operate. However, its vulnerability overshadowed its stability and effectiveness as a weapons platform. The army eventually shifted its focus from “flying jeeps” to traditional attack helicopters.
