Nearly 20 years before harrier jets proved effective for vertical take-off and landing platforms, the U.S. Navy considered another approach to deploying fighters without runways.
In the years following World War II, the United States found itself trying to adapt its newly established air power to a world with nuclear weapons. The United States knew that its monopoly on the atomic bomb would not last forever, and by the mid-1940s, it seemed obvious that the Soviet Union would eventually become the second nuclear power on earth.
That day came sooner than many expected, with a nuclear explosion at the Semipalatinsk test site in modern-day Kazakhstan on August 29, 1949, ushering in an era of military competition between the two global powers. In just a few decades, the total stockpiles of nuclear weapons in the United States and the Soviet Union exceeded 70,000. Today, the theory of mutually assured destruction is often discussed only from the perspective of the United States and the Soviet Union, but with such a large inventory, when the two superpowers gaze at each other from their respective hemispheres, it is the world that is really in balance.
Nuclear war and the need for vertical take-off and landing aircraft
For some time now, nuclear war seemed not only possible, but even possible, as both countries were preparing for territory and prestige. In some defense circles, the question is really not whether nuclear war will break out ... It's about when it breaks out.
The fact that only 21 years have elapsed since the end of the First World War and the outbreak of the Second World War is an important context to consider when looking back at the decades following the Second World War. The military leaders of both countries are mostly old and have seen not one, but two world wars, each setting a new precedent for the terrible destructive power of war. For much of the world today, World War III is not a hypothetical concept. World War III seems to be a very real and possible scenario, and one thing that both sides are certain of is that the next global conflict will begin in the same way as the previous one: nuclear weapons.
While U.S. politicians largely see the concept of nuclear war as the ultimate state of diplomatic failure, U.S. military leaders are in an enviable position of having to plan to win the war. This meant finding ways to continue fighting after the first nuclear weapons landed, and one approach embodied in many military aircraft development programs was the concept of VTOL or vertical take-off and landing.
Throughout world war II, the world witnessed an explosion in the development of aviation infrastructure, as landing runways appeared in every area of the battle. These airstrips, which spread across Europe and the Pacific, will almost certainly be seen as a great threat to the Soviet Union in the new conflict, as they will provide ample opportunity for the United States and its allies to launch heavy payload bombers deep into Soviet territory.
U.S. Air Force B-29 in 1945 (U.S. Air Force photo)
As a result, the Pentagon's top brass believed that the airstrip would be one of the first targets of a Soviet nuclear attack. If they're right, and the U.S. can't expect to deploy airstrips around the globe to support combat operations, they need a new type of fighter that can take off and land without a manicured runway.
The U.S. Air Force is considering using the Canadian flying saucer VZ-9 Avrocar. The U.S. Navy sought its own solution, and by 1950 they had received proposals from Lockheed and Convair.
Lockheed XFV "Salmon"
While the Pentagon requires both VTOL and landing aircraft, the Navy sees VTOL platforms as an opportunity to deploy interceptor fighter jets from non-aircraft carriers. In fact, if necessary, the Navy even considered launching VTOL fighters from merchant ships in the New World War.
In June 1951, Lockheed received a naval contract to build the XFV-1; a prototype fighter with traditional wings, a large reinforced X-tail, and a 5,850-horsepower turboprop engine that rotated a pair of three-bladed twin-rotor propellers to make the aircraft look like the illegitimate children of helicopters and propeller-driven fighter jets. Most unusually, the plane was designed to take off and land at the tail, with the nose pointing straight into the air.
(Lockheed Martin)
Lockheed called on prominent aviation pioneer Kelly Johnson to design their VTOL XFV, at a time when one might argue that the project could not have gone into better hands. Johnson had just finished developing the P-38 Lightning, followed by the P-80 Meteor, the first U.S. jet fighter. As an aeronautical engineer, his long and legendary career eventually included overseeing the first such platforms, such as the U-2 spy aircraft, the SR-71 Blackbird, and the F-117 Nighthawk.
For testing purposes, the XFV-1 was equipped with an awkward-looking landing gear that included wheels mounted at the bottom of the lower tail. In December 1953, when chief test pilot Herman 'Fish' Salmon managed to get the plane to briefly "jump" during the tax test, the XFV-1 got its first taste of the sky. Less than a year later, in June 1954, it would take off all the way to the skies for its first real flight.
XFV-1 landing gear (U.S. Navy photo)
Unfortunately, the Allison YT40-A-6 turboprop engine mounted on the prototype was not powerful enough to manage the actual vertical take-off or landing. Instead, Lockheed plans to use the upcoming (and more powerful) Allison T54 engine, which will produce 7,100 horsepower, but problems with engine development mean the XFV's much-needed powerplant will never come.
Pilot boarding the XFV-1 scaffolding (Lockheed)
The XFV-1 prototype made a total of 32 short-haul flights and even successfully maneuvered the nose in a short period of time, but never completed a single vertical take-off or landing.
Convair XFY Pogo
Convair's view of the vertical take-off and landing premise has many similarities to Lockheed. Like the XFV, Convair's XFY Pogo is designed to stand upright at its tail, so it can take off like a helicopter with its pair of three-bladed conjunct propellers. Then, once in the air, the plane reorients and flies forward like a traditional propeller aircraft.
XFY on the launcher (Wikimedia Commons)
For its purposes, Pogo was more successful than Lockheed's outings. The first outdoor test flights began in August 1954 and shortly thereafter underwent a series of 70 successful vertical take-off and landing exercises. By November of that year, Conville's team was in test pilot and naval reservist James F. Kennedy. Led by Lieutenant Colonel Scotts" Coleman, they achieved their first successful transition from vertical to horizontal flight. To make the transition easier, the pilot's seat in the cockpit is mounted on a gimbal, with a pilot's orientation of 45 degrees in vertical flight mode and 90 degrees when flying horizontally.
Despite the success, subsequent test flights began to reveal problems with the premise of the VTOL upright fighter. During the flight, pogo lacked air brakes or spoilers to help it slow down after flying at high speeds, but what was even more troubling was how difficult the unusual plane landed.
The pilots had to look back at the ground and slowly lower the fighter to the tail. Eventually, a low-power radar system was installed that could help pilots measure their altitude through a series of lights, but landing was still tricky. It soon became clear that the Navy's plan to mount these fighters on a variety of non-carrier ships simply didn't work, because only the best pilots in the force had a chance to land the planes.
(U.S. Navy photo)
Further cursing the concept were the jet fighters of that era, whose speeds were as high as Mach 2, while the propeller-driven vertical takeoff fighters the Navy was testing could not even break through the sound barrier. Eventually, the concept was abandoned, and by the end of 1956, both Lockheed and Conville's vertical take-off fighter jets were revived in the museum.
Eventually, the U.S. Navy will invest heavily in fixed-wing and sweep-wing carrier-based fighter jets such as the F9F Panther, F-14 Tomcat, and F/A-18 Hornet. However, fighters that took off vertically or short distances still entered the U.S. arsenal. The U.S. Marine Corps began using the AV-8A Harrier in 1971, and today, the Marine Corps is experimenting with the use of amphibious assault ships to launch a short takeoff vertical landing variant of the Joint Strike Fighter, the F-35B.