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F8U-3 Crusader Was ‘Really Hot’ Might Have Been

When it first took to the air on June 2, 1958 with test pilot John W. Konrad at the controls, the F8U-3 Crusader III was the bright shining hope of its famous planemaker, Vought, a builder of U.S. Navy warplanes for decades. This was the carrier-based interceptor that would prevent Soviet bombers from reaching the U.S. Navy fleet. Combining acceleration, speed and range, the Crusader III would use its robust radar and air-to-air missiles (but no gun) to guard America’s maritime forces.

Vought F8U-3 Crusader III

A Vought F8U-3 Crusader III during flight testing. The under-fuselage fins folded up into a horizontal position for take off and landing.U.S. Navy photo

The F8U-3 was flying only five days after its archrival, the McDonnell F4H-1, later to be called the Phantom II. Everyone at Vought was convinced that, of the two competitors, the F8U-3 was the “hot” jet – “really hot,” said Vought test pilot Joe Angelone – the stellar performer that had an inevitably bright future. No one was concerned that on the maiden flight Konrad experienced a throttle jam and had to cut short the flight after 38 minutes. The Crusader III was the wave of the future.

Except that it wasn’t. An almost entirely new design inspired by the F8U-1 and F8U-2 Crusader fighters (there was no Crusader II), the F8U-3 ended up being a “might have been,” a stroke of genius that was bypassed by the times it helped to define. It was “the best fighter never produced,” said Navy engineer George Spangenberg.


Design Effort

In the mid-1950s, reeling from years of problems with jet engines and equipped with fighters that were lackluster at best, the U.S. Navy rejected a proposed new fighter from Grumman but authorized two other companies, Vought and McDonnell, to proceed with new designs. Initially, the Navy wanted both aircraft, both of which would be armed with Sparrow missiles in an era when everyone knew that a fighter didn’t need guns. Key figures in the Navy leadership favored the McDonnell approach, which called for a crew of two and promised twin-engine reliability. Vought studied possible two-seat F8U-3 designs, both side-by-side and tandem, but concluded that installing a second crewmember would seriously flaw the aerodynamics of the aircraft.

Although some in the Navy viewed McDonnell’s use of the relatively new General Electric J79 turbojet engine as high risk, the engine soon proved its mettle. At about the same time, it appeared on the B-58 Hustler, F-104 Starfighter and other aircraft.

Vought F8U-3 Crusader III

A Vought F8U-3 Crusader III conducts a flight test. U.S. Navy photo

The F8U-3 drew its power from a single Pratt & Whitney J75-P-5A turbojet engine generating 29,500 pounds of thrust with afterburning. To achieve stability at Mach 2.0 and beyond, it was fitted with large vertical ventral fins under the tail that rotated to the horizontal position for landing. In addition to the turbojet, Vought made provisions for a Rocketdyne XLF-40 liquid-fueled rocket motor with 8,000 pounds of thrust in a version called the F8U-3F. Subsequently, another rocket motor was studied, but the Crusader III never flew with a rocket engine.

The F8U-3 had a variable incidence wing, like its earlier stablemate the F8U Crusader,  to improve visibility for deck landings. A boundary layer control system of the flap-blowing type was to increase the lift coefficient during critical phases of take-off and landing.

The F8U-3 especially impressed observers with its acceleration, speed and good handling qualities at high Mach numbers. Beyond Mach 2.0, it was limited only by its Plexiglas windshield and by lower wing skin temperatures. In the monograph “Vought F8U-3 Crusader III” (Simi Valley: 2010, Steve Ginter), author Tommy H. Thomason writes that claims of a Mach 2.79 airspeed were an exaggeration, but that the fighter was comfortable at Mach 2.39. For the operational F8U-3 being envisioned, Vought worked on a new windscreen that would have prevented this feature from being the limiting factor on airspeed.

Vought built three F8U-3s and was soon immersed in a head-to-head competition with McDonnell conducted by a Navy evaluation team headed by Capt. Bob Elder, a jet pioneer. The F8U-3 project pilot, Lt. William Lawrence, called the Crusader III’s climb performance “dramatic.”


Drawbacks and Drama

Everyone associated with the F8U-3 remembers its performance as spectacular. Another Navy pilot Lt. Donald Engen jokingly compared it to the SB2C Helldiver dive-bomber he’d flown in World War II and said it was “a little speedier.” But it soon became apparent that the fighter had its share of drawbacks.

The F8U-3 had an unacceptable tendency to go into a compressor stall at high Mach numbers, a problem that lingered after several fixes were tried. It had a remarkably long takeoff run, a fully satisfactory 2,800 feet while on afterburner but three times that length without. Given a goal of 37,500 pounds gross weight, the Crusader III reached 40,086. Given a goal of capability to carry four Sparrow missiles, it was designed to carry three.

Vought XF8U-3 at Wallops Island 1959

One of the F8U-3 Crusader IIIs transferred to NASA after the loss of the Navy competition to the F4H-1 Phantom II. NASA photo

On the other hand, and as Vought Vice President (and designer) Russell Clark frequently pointed out, the F8U-3 was 5,000 pounds lighter than the F4H-1, used 20 percent less deck stowage space, was 100 knots faster, and had a cockpit set-up into which a new pilot could easily transition from the F8U-2.

The fly-off competition in 1958 was intense but brief. Many associated with the Vought aircraft were convinced that the Navy had decided on the McDonnell entry before the contest began. Both aircraft performed well in the fly-off, but by then the Navy had backed away from wanting both, and, on Dec. 17, 1958, announced its selection of the F4H-1. Vought continued to have plenty of defense business building F8U-2s and, in later years, the A-7 Corsair II.

The three F8U-3s were relegated to the new National Aeronautics and Space Administration, NASA – two to the Langley facility in Virginia and one to the Ames center at Moffett Field, Calif. For years thereafter, aviators told tall tales of NASA F8U-3s waxing Navy F4H-1s in east-coast mock dogfights. It’s unclear where the lore originates, because the Crusader IIIs made very few flights and were never in the same location as the handful of existing F4H-1s. The west-coast aircraft apparently never flew in its NASA livery.

At various times, plans existed for a simplified day fighter of the F8U-3 (with smaller radar), a British version, and a U.S. Air Force interceptor version for the Air Defense Command.When the Pentagon’s military designation was overhauled on Oct. 1, 1962, the F4H-1 became the F-4B, the first of more than 5,000 Phantom IIs that gained fame in Vietnam and the Cold War, many of them retrospectively armed with guns. The F8U-1 became the F-8A and the F8U-2 the F-8B, but the F8U-3 never received a new designation: By then, all three of these promising fighters had been scrapped.


Robert F. Dorr is an author, U.S. Air Force veteran, and retired American diplomat who...

    li class="comment even thread-even depth-1" id="comment-73921">

    The “other aircraft” that used the J-79 engine was the A3J/RA5C Vigilante US Navy Bomber/Recon aircraft.