The Convair F2Y Sea Dart was a unique American seaplane fighter aircraft that rode on twin hydro-skis for takeoff. It only flew as a prototype, and never entered production, but it is still the only seaplane to exceed the speed of sound.
Convair's proposal gained an order for two prototypes in late 1951. Twelve production aircraft were ordered before a prototype had even flown. No armament was ever fitted to any Sea Dart built, but the plan was to arm the production aircraft with four 20 mm cannon and a battery of folding-fin unguided rockets. Four of this order were redesignated as service test vehicles, and an additional eight production aircraft were soon ordered as well.
Power was to be a pair of afterburning Westinghouse XJ46-WE-02 turbojets, fed from intakes mounted high above the wings to avoid ingesting spray. These engines were not ready for the prototypes and twin Westinghouse J34-WE-32 engines of just over half the power were installed.
The US was not the only country to consider the hydroski. The Saunders-Roe company of the United Kingdom, who had already built an experimental flying-boat jet fighter, tendered a design for a ski equipped fighter but little came of it.
The underpowered engines made the fighter sluggish, and the hydro-skis were not as successful as hoped; they created violent vibration during takeoff and landing, despite the shock-absorbing oleo legs they were extended on. Work on the skis and oleo legs improved this situation somewhat, but they could not cure the sluggish performance. The Sea Dart proved incapable of supersonic speed in level flight with those engines; not helping was its pre-area rule shape, which meant higher transonic drag.
The second prototype was cancelled, so the first service test aircraft was next to build and fly. This one was fitted with the J46 engines, which performed below specification. However, speeds in excess of Mach 1 were attained in a shallow dive with this aircraft, making it the only supersonic seaplane to date. This aircraft disintegrated in mid-air during a demonstration to Navy officials and the press, killing Convair test pilot, Charles E. Richbourg.
Even before that, the Navy had been losing interest (problems with supersonic fighters on carrier decks having been overcome) and the crash relegated the Sea Dart program to experimental status. All production aircraft were cancelled, though the remaining three service test examples were completed. The two final prototypes never flew.
All four remaining Sea Darts survive to this day. The prototype is awaiting restoration for the Smithsonian Institution, and is in bad shape. The others are at the San Diego Aerospace Museum, the Wings of Freedom Air and Space Museum at Willow Grove, Pennsylvania, and at the Lakeland, Florida airport.
|plane or copter?=plane |jet or prop?=jet
|crew=1 |length main=52 ft 7 in |length alt=16 m |span main=33 ft 8 in |span alt=10.3 m |height main=16 ft 2 in |height alt=4.9 m |area main=568 ft² |area alt=53 m² |empty weight main=12,625 lb |empty weight alt=5,730 kg |loaded weight main=16,500 lb |loaded weight alt=7,480 kg |max takeoff weight main=21,500 lb |max takeoff weight alt=9,750 kg
|performance header=Performance (estimated) |max speed main=825 mph |max speed alt= 1,325 km/h |range main=513 mi |range alt=446 nm, 826 km |ceiling main=54,800 ft |ceiling alt=16,700 m |climb rate main=17,100 ft/min |climb rate alt=86.7 m/s |loading main=29.0 lb/ft² |loading alt=142 kg/m² |thrust/weight=1.45