Rockwell XFV-12: Proof the British Build Better VTOL Jets Than the Yanks

American and Soviet pilots alike had their jaws hit the floor the first time they saw the British Hawker Siddeley Harrier take to the sky as if by magic back in the late 1960s. Though on paper, the British RAF and Royal Navy had a fraction of the resources of the Americans or the Soviets. But neither superpower produced a VTOL jet that could match the Harrier.
Rockwell XFV-12 10 photos
Photo: Rockwell International
Rockwell XFV-12Rockwell XFV-12Rockwell XFV-12Rockwell XFV-12Rockwell XFV-12Rockwell XFV-12Rockwell XFV-12Rockwell XFV-12F-35 and AV-8B
Not that either side didn't try their darndest. More well-known examples like the Yakovlev Yak-38 and the Lockheed XV-4 Hummingbird may have managed to get off the ground. But not the American Rockwell XFV-12. Though it may have won a contract competition to supply the U.S. Navy with a Harrier equivalent, the results made all the impact of a wet noodle. No, seriously, it was that bad. It's why almost no one even remembers it.

The XFV-12's unfortunate story begins in the year 1972. By that stage, the British Harrier had already been in service for three years, seeing its debut in April 1969. This period of utter domination of the military VTOL sector by the British must have been nothing short of outrage to the United States Military.

The United States spent $80.71 billion in 1972 alone on defense, or 6.52 percent of the nation's total GDP. Therefore, playing second fiddle to the British with that level of investment necessitated a new initiative on the part of the Navy in particular. At the same time, the Navy was also conducting design studies for a new type of light aircraft carrier more in line with contemporary European carriers called the Sea Control Ship (SCS).

This new Navy request for proposals to build VTOL jets to fit these concept aircraft carriers turned into a competition between two American aerospace firms. On the one hand, there was Convair and their Model 200. By most accounts, the Model 200 was a relatively conventional VTOL design incorporating one turbojet engine for horizontal fight and two lift jets for vertical takeoff and landings.

Rockwell XFV\-12
Photo: Rockwell International
Rockwell International's plan, on the other hand, was anything but conventional, even by VTOL standards. Even one hard look at the silhouette of their XFV-12 proceeds to get stranger and stranger with every passing second you stare at it. As if some of the components of this novel airframe were copied and pasted from other, more recognizable aircraft.

Of course, this was totally on purpose. Vital components of the XFV-12's airframe, like the air intakes, the nose section, the cockpit, and the landing gear assembly, were derived from famous jets like the F-4 Phantom II and the A-4 Skyhawk. Only after gawking at the XFV-12's bizarre wing tip-mounted control surfaces and aggressive front canard system do these familiar faces reveal themselves.

All these funky shapes and proportions serve what, at least on paper, was an important function. You see, the XFV-12, like the British Harrier, only utilized a single engine for both vertical and horizontal flight. The key difference was how each jet concentrated this thrust downwards to lift itself vertically off the ground.

In the Harrier, this single engine was connected to a series to thrust augmenting nozzles. Which simply spewed very high propulsive thrust either at the ground or straight forward, depending on the pilot's input. But in the case of the Rockwell XFV-12, this engine exhaust thrust wasn't directed straight at the ground.

Rockwell XFV\-12
Photo: Rockwell International
Instead, this exhaust was directed straight into the underside of each wing. As if to push all the force from the engine directly onto lift-generating surfaces instead of directing it away from the airframe like a Harrier. Dubbed a thrust-augmented wing, Rockwell engineers were hopeful the VTOL capabilities of their new design would exceed even that of the Harrier.

The XFV-12 was officially revealed to the public on August 26th, 1977, in front of a large crowd gathered outside Rockwell International's primary facility in Columbus, Ohio. Though the reaction by the crowd to this most bizarre of airframes must have been nothing short of abject amazement, it would sadly be the absolute zenith of the model's cultural significance.

Even while this first XFV-12A prototype was getting some glamor shots, work had already been abandoned on the type's second example. It was as if even Rockwell themselves knew deep down the airplane had little chance of ever working. As it happens, tethered hover tests of the XFV-12 proved if anyone at Rockwell did have these concerns, they were more than justified for their hunch.

With measurements of 43 feet 11 inches (13.39 m) long and a 28 feet 6.25 inch (8.7 m) wingspan, the XFV-12 sit comfortably within the dimensions of more conventional Air Force and Navy jets like the F-15 Eagle and F-14 Tomcat. With the addition of a Pratt & Whitney F401-PW-400 turbojet, also found in the F-15, things should have been promising.

Rockwell XFV\-12
Photo: Rockwell International
But alas, the above-mentioned tethered tests revealed the XFV-12's thrust-augmented wing could only generate enough lift to carry roughly 70 percent of the airframe's gross weight. Or, from the glass-half-empty perspective, the level of vertical lift generated by the XFV-12's wings was as much as 30 percent weaker than initial estimates had predicted.

What this translated to is that had the XFV-12 attempted to take off on its own, it'd either fail to take off at all or reach a pathetically low altitude before the lack of lift sent the plane pancaking back to Earth. Such an accident would no doubt seriously injure the pilot or perhaps far worse. A full eight years passed between the first XFV-12A mockup's completion at Rockwell's R&D facility and its unceremonious cancelation by the U.S. Navy in 1981.

At the time, it was thought the XFV-12 project shoved as much as $1 billion in government funding before its unceremonious end. When adjusted for considerable inflation, the XFV-12's development cost the Navy an eye-watering $3.26 billion for one measly prototype. By comparison, the Harrier jump jet and all its derivatives have sold in their hundreds for decades. To the point where even the Americans had to utter that timeless phrase, "If you can't beat them, you might as well join them."

The first American adaptation of the British Aerospace Harrier II entered service with the U.S. Navy and Marine Corps in January 1985. Even in 2023, the American-led F-35B Lightning program designed to replace the Harrier is overseen in part by Lieutenant Commander Stuart Greenfield, a Royal Navy air engineer.

F\-35 and AV\-8B
Photo: USMC/Samuel Ruiz
It proves that the British are at the heart of every successful NATO VTOL jet of the last six decades. Even if the airframe in question sports USAF camouflage and roundels and also sings the star-spangled banner with its own jetwash.
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