https://en.wikipedia.org/wiki/Convair_F2Y_Sea_Dart
The Convair F2Y Sea Dart was a unique American seaplane fighter aircraft that
rode on twin hydro-skis for takeoff. It flew only as a prototype, and never
entered production. It is the only seaplane to have exceeded the speed of sound.
The Sea Dart began as Convair's entry to a 1948 U.S. Navy contest for a
supersonic interceptor aircraft. There was at the time much skepticism about
operating supersonic aircraft from aircraft carrier decks, which explains why
the U.S. Navy ordered so many subsonic fighters at that time. The worry had some
foundation, since many supersonic designs of the time required long takeoff
rolls, had high approach speeds and were not very stable or easy to control -
all factors that were troublesome on a carrier.
Ernest Stout's team at Convair's hydrodynamic research laboratory proposed to
put a Delta Dagger on water skis.
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 20mm Colt Mk12 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.
The prototype was fitted with an experimental single ski, which proved more
successful than the twin-ski design of the second service test aircraft. Testing
with several other experimental ski configurations continued with the prototype
through 1957, after which it was placed into storage.
The aerodynamic stability of the long, narrow, single-surface ski did not go
unnoticed by aircraft designers, leading to the placement of a speed brake of
similar configuration on the top of the McDonnell Douglas F-15 fighter.
The US was not the only country to consider the hydroski. The Saunders-Roe
company of the United Kingdom, which had already built an experimental flying
boat jet fighter,first flying in 1947 the SR.A/1, tendered a design for a
ski-equipped fighter but little came of it.
Role
Seaplane fighter
Manufacturer
Convair
First flight
14 January 1953
Retired
1957
Status
Canceled
Primary user
United States Navy
Number built
5
Role
Seaplane fighter
Manufacturer
Convair
First flight
14 January 1953
Retired
1957
Status
Canceled
Primary user
United States Navy
Number built
5
The aircraft was built in Convair's San Diego facility at Lindbergh Field and
was taken to San Diego Bay for testing in December 1952. On 14 January 1953, the
aircraft with E. D. "Sam" Shannon at the controls, inadvertently made its first
short flight during what was supposed to be a fast taxi run; its official maiden
flight was on 9 April.
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 the J34 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 built
and flown. This 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. On 4
November 1954, Sea Dart, BuNo 135762 disintegrated in midair over San Diego Bay
during a demonstration for Navy officials and the press, killing Convair test
pilot Charles E. Richbourg when he inadvertently exceeded the airframe
limitations. Richbourg was a 31-year-old Navy veteran of the Second World War.
He was quickly pulled from the water but did not survive the breakup of the
airframe. He is buried in Saint Augustine National Cemetery in Florida.
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.
Specifications (F2Y-1)
General characteristics
Crew: one
Length: 52 ft 7 in (16 m)
Wingspan: 33 ft 8 in (10.3 m)
Height: 16 ft 2 in (4.9 m)
Empty weight: 12,625 lb (5,730 kg)
Loaded weight: 16,500 lb (7,480 kg)
Max. takeoff weight: 21,500 lb (9,750 kg)
lbf each) turbojets, 6,100. lbf (27 kN) each
Performance (estimated)
Maximum speed: 825 mph (1,325 km/h)
Range: 513 mi (446 nm, 826 km)
Service ceiling: 54,800 ft (16,700 m)
Take-off run: 5,500 ft (1,676 m)
Landing run: 1,500 ft (305 m)
Rate of climb: 17,100 ft/min (86.7 m/s)
Thrust/weight: .56 (max loaded).96 (empty)
Armament
Rockets: Fin-Folding Aerial Rockets
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