Convair F2Y Sea Dart

🇺🇸 UNITED STATES
RETIRED
Experimental supersonic seaplane interceptor — only seaplane to exceed Mach 1
🚀
MAX SPEED
Mach 1.25
1,325 km/h
⛰️
CEILING
16.8 km
55,121 ft
🗺️
RANGE
826 km
513 mi
📅
FIRST FLIGHT
1953
✈️
Speed Ranking
#222 fastest of 262 aircraft in this database

✈️ Full Specifications

DesignationF2Y-1 / YF2Y-1
ManufacturerConvair
Country🇺🇸 United States
First Flight1953
Retired1956
Crew1
Length16 m (52.5 ft)
Wingspan10.3 m (33.8 ft)
Height4.92 m (16.1 ft)
Empty Weight5,730 kg (12,635 lb)
Max Takeoff Weight7,480 kg (16,493 lb)
Max Speed (Mach)1.25
Max Speed1,325 km/h (823 mph)
Service Ceiling16,800 m (55,121 ft)
Range826 km (513 mi)
Engine2 × Westinghouse J46-WE-2 turbojets
Thrust (each)Dry 14.7 kN · AB 27.1 kN
Production5

🌐 Operators

✈️ United States Navy

🔁 Variants

  • XF2Y-1 — Single prototype with single ski
  • YF2Y-1 — Four pre-production aircraft with twin skis

⚔️ Armament

Planned: 4× 20mm Colt Mk 12 cannon, FFAR rocket pods Never installed on prototypes

Overview

The Convair F2Y Sea Dart is the only seaplane ever to exceed the speed of sound. Developed in the early 1950s for the U.S. Navy as a potential answer to the problem of operating supersonic fighters from carriers whose decks were not yet long enough, the Sea Dart used retractable hydro-skis to take off and land from water. Only five aircraft were built before the program ended, but the design remains a one-of-a-kind achievement in supersonic aviation history.

Design & Development

The Sea Dart used a delta wing — Convair’s signature shape of the era — and twin Westinghouse J46 engines mounted high above the fuselage to keep their intakes out of spray. Underneath, two retractable hydro-skis extended for water operations and retracted into the fuselage for flight. The first prototype, BuNo 137634, was launched at San Diego Bay on January 14, 1953.

Hydrodynamic problems plagued the design. The original single-ski configuration vibrated violently during high-speed taxi, and the production-intent twin-ski layout was only marginally better. The J46 engines were also underpowered for sustained supersonic flight; the design speed of Mach 1.25 was never reliably achieved in operational testing.

Operational History

On August 3, 1954, test pilot Charles E. Richbourg pushed the second YF2Y-1 past Mach 1 in a shallow dive — making the Sea Dart the first and only seaplane ever to break the sound barrier. The flight is officially recognized but considered marginal: the airframe was not stable above Mach 1, and the Navy was already cooling on the concept by then. On November 4, 1954, the same airframe broke up in mid-air over San Diego Bay, killing Richbourg.

With angled flight decks and the steam catapult solving the supersonic-carrier problem, the Navy quietly cancelled the program in 1956. Two airframes survive — one at the San Diego Air & Space Museum and one at the Wings Over the Rockies Museum.

Legacy

The F2Y Sea Dart represents a road not taken in carrier aviation. Modern catapult and arresting-gear technology, combined with larger carriers, made the seaplane fighter concept obsolete almost as soon as the prototypes flew. The Sea Dart remains a fascinating footnote — proof that supersonic flight from water was possible, even if the operational case never materialised.

References

  • U.S. Navy YF2Y-1 flight test reports, 1953–1955
  • San Diego Air & Space Museum collection records
  • “Convair Advanced Designs” by Robert E. Bradley
✈️
Sean

Aviation enthusiast and curator of the Supersonic Aircraft Encyclopedia. Sean has been passionate about different kinds of flight since he was little and maintains detailed specs and history for every aircraft featured on this site.

EN
English 繁體中文 简体中文 日本語 한국어 Français Deutsch Español Русский العربية Português
Scroll to Top