It looked like nothing else in the sky: a stubby twin-engine fighter whose nose stopped dead at the wing, as if someone had sawn the front off a normal aeroplane. Test pilots loved it. Comic-book readers worshipped it. And the U.S. Navy, after flying it against the best fighters in the world, quietly walked away from it.

The Grumman XF5F Skyrocket first left the ground on 1 April 1940 — an April Fool’s Day birthday for one of aviation’s great might-have-beens. Only one was ever built. Yet its DNA, and its legend, long outlived the single prototype.

This is the story of the fighter that seemed to win everything except the one contest that mattered: production.

The fighter with no nose

In the late 1930s the U.S. Navy toyed with a radical idea: a twin-engine fighter small and light enough to fly from a carrier deck. Grumman’s answer, ordered on 30 June 1938, was the XF5F-1 — a design obsessed with one thing above all, the pilot’s view over the nose for the terrifying business of landing on a moving ship.

So Grumman simply deleted the nose. The forward fuselage did not extend past the wing’s leading edge, giving the pilot an almost unobstructed view forward. Two Wright R-1820 radials sat on the wings, their propellers geared to spin in opposite directions to cancel out each other’s torque — a refinement that made the aircraft beautifully behaved on take-off.

Under 10,000 pounds and bristling with power, the Skyrocket promised a blistering climb rate. Early flights were dogged by engine-cooling trouble that forced redesigned oil ducts — but once sorted, the pilots who flew it came away impressed.

Winning the fly-off, losing the war of production

In 1941 the Navy pitted the XF5F against a formidable field — the Spitfire, Hurricane, P-40, P-39, the XF4U Corsair, the F4F Wildcat and others. By some accounts the little Grumman came out on top, and one much-quoted assessment of the trials is unambiguous.

Historians still argue about how decisive that result really was, and the raw prototype had real flaws — landing-gear troubles chief among them. What is not in dispute is the outcome: the Navy chose to mass-produce single-engine fighters instead. The rugged F4F Wildcat was already in hand, the F4U Corsair and F6F Hellcat were coming, and a twin-engine carrier fighter was a complication the fleet did not need in 1941.

The afterlife of a prototype

The one Skyrocket soldiered on as a research aircraft, gathering data on twin-engine handling until a gear-up landing on 11 December 1944 finally struck it from the rolls. But its ideas did not die with it: the experience fed directly into the twin-engine Grumman F7F Tigercat, a genuine production fighter that arrived too late for the Second World War.

And then there was fame of a stranger kind. The XF5F’s unmistakable silhouette was borrowed by the creators of the 1940s comic-book hero Blackhawk as the super-weapon flown by his squadron — making the fighter that never entered service one of the most recognisable aircraft of its era to a generation of readers.

The Skyrocket is a perfect aviation paradox: a machine that reportedly beat the world’s best fighters, inspired a comic-book legend, seeded a real production aircraft — and never fired a shot in anger. Sometimes the aircraft we remember most fondly are the ones that never had to prove us wrong.

Sources: Wikipedia; Vintage Aviation News; HistoryofWar.org; GlobalSecurity.org; Rex’s Hangar.