XF2Y-1 Sea Dart: A Jet Fighter on Water Skis
Convair's Sea Dart waterborne jet fighter was a brilliant mistake whose time never came
“From the sea…” was a strategic doctrine that might have included jet fighters if the Convair F2Y Sea Dart had succeeded.
The Sea Dart began as Convair’s entry to a 1948 U.S. Navy competition for a supersonic interceptor. It was a product of the same design team that produced the delta-winged XF-92A testbed and the F-102 Delta Dagger interceptor for the Air Force.
In the 1950s, a few Navy engineers and planners began to pursue a delta-winged supersonic fighter that could take off from and land on water. Some Navy leaders had doubts about employing supersonic fighters aboard aircraft carriers because of their long takeoff rolls, high-speed approaches and general instability.
It was a time when jet engines were thoroughly unreliable and jet aircraft had not yet fully replaced propeller-driven warplanes. Using open water to takeoff and land was an idea that appeared to offer great flexibility.
The Sea Dart had a watertight hull and was the only flying boat fighter ever tested in the United States.
In 1951, the Navy awarded a contract to Convair, the San Diego, Calif. company created by the merger of Consolidated and Vultee, to build two prototypes of a single-seat, delta-wing seaplane fighter, the F2Y Sea Dart.
Eventually, the Navy placed firm orders for no fewer than 22 of the planes, including two XF2Y-1 “experimental” versions, four YF2Y-1 “service test” aircraft and sixteen F2Y-1 production aircraft, or, roughly, enough for a squadron.
Fanciful artists’ concepts from the period showed squadrons of Sea Darts operating in the open ocean, being fueled and loaded with ammunition by accompanying fleets of warships. A Washington, D.C., newspaper published a drawing of a Sea Dart operating from the Tidal Basin to defend the capital from Soviet bombers. The basin is about three feet deep and in no way suitable for any seaplane, but the image was captivating.
The Sea Dart was not without aesthetic appeal, but in engineering terms it left something to be desired. When Convair test pilot E. D. “Sam” Shannon took the first plane, designated XF2Y-1, aloft at San Diego on its first official flight on April 9, 1953, the Sea Dart was already in trouble.
The Sea Dart arrived full-blown in an era when jet engines were unreliable and Navy Westinghouse jet engines, especially the J40 and J46, had more problems than others. The Sea Dart was to be powered by twin 6,000-pound thrust Westinghouse XJ46-WE-02 turbojet engines. However, the XF2Y-1 prototype was finished before the XJ46 was available, so it was fitted with twin 3,400-pound thrust Westinghouse J34-WE-32s. The Sea Dart was badly underpowered with J34s (although they were more reliable than other powerplants of the era) and could not attain its intended supersonic speed. The aircraft made use of hydro-skis, which, as it turned out, provided a rough ride on takeoff and landing and were less effective than expected. When stationary or taxiing slowly in the water, the Sea Dart moved along the surface with the trailing edge of its wings brushing the water. The skis were extended when the aircraft reached about 10 miles per hour during its takeoff run.
A Navy plan for mobile bases for water-borne aircraft began to lag and, in the end, never became reality.
Moreover, the Korean War was going on. The Navy was embarrassed that its carrier decks could not boast a conventional jet fighter with the capabilities of, say, the Air Force F-86 Sabre or the Soviet MiG-15.
The Sea Dart program went through several changes on paper and in fact as the Navy changed the number of planes it wanted from seven to 22 to, finally, just five. Several engines were considered for a production version of the Sea Dart.
For the most part, the aircraft performed well in tests, but the Navy seemed to be unable to decide what to do with it.
The program took a tragic turn on Nov. 4, 1954, when Convair test pilot Charles E. “Chuck” Richbourg was killed in the no. 2 Sea Dart, called a YF2Y-1, as it disintegrated during a low-level, high-speed fly-past with the press watching and television cameras running. Some Americans saw this happen on live television. The crash was the lead item in the day’s television and print news.
As a result of the tragedy, the Navy canceled all the production F2Y-1s but stayed with its plan to build one more XF2Y-1 prototype and the three remaining YF2Y-1 service test aircraft.
Improving An Idea
Tests resumed after its makers redesigned the lone prototype XF2Y-1 with a single hydro ski replacing dual skis. An unhappy compromise, the new hydro ski was not fully retractable. Moreover, the wells for the old twin skis had not been faired over. The new single ski had a pair of retractable beaching wheels at the end, intended to permit the aircraft to beach itself. Another aircraft, a YF2Y-1, flew with a new version of twin skis – bringing to three the number of Sea Darts that actually made it into the air.
While the two surviving Sea Darts resumed the flight test program, two more were built but never flown. They were eventually scrapped.
The sole XF2Y-1 and YF2Y-1, with their differing ski configurations, both demonstrated an ability to operate in waves up to 10 feet high and to fly faster than sound in a shallow dive. It is questionable whether a Sea Dart would have been able to prevail in a dogfight or to maintain supersonic speed in level flight as had been hoped.
Documents preserved at the San Diego Aerospace Museum show that Convair and Navy experts solved one technical problem after another. By 1957, they had a Sea Dart design that would have worked perfectly well in service, although its air-to-air capability remained open to question. By that time, in any event, interest in sea bases and sea-borne combat planes had waned. Moreover, the Air Force F-100 Super Sabre and the Navy F8U Crusader were now pushing the envelope farther than the Sea Dart could ever go.
According to General Dynamics Aircraft and Their Predecessors, by John Wegg, the Sea Dart logged over 300 flights in 46 months before the Navy discontinued the program in 1957.
The Navy abandoned plans to produce an F2Y-2 version incorporating area rule to enhance supersonic flight and powered by two 15,000-pound thrust Pratt & Whitney J75 turbojets.
Five years later, when the Pentagon’s system for naming aircraft was overhauled on Oct. 1, 1962, the F2Y was re-named the F-7A. It was the only naval aircraft to be given a new name five years after it ceased flying. All four surviving Sea Darts are in the hands of various museums around the country.