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Bell Model 533 (High Performance Helicopter)

Experimental / Research Helicopter

One Bell Model 533 was built for the United States Army to research high-speed rotor flight.
Authored By: Staff Writer | Edited: 12/13/2017
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Year: 1962
Status: Retired, Out-of-Service
Manufacturer(s): Bell Helicopter - USA
Production: 1
Capabilities: Transport; X-Plane;
Crew: 2
Length: 57.09 ft (17.4 m)
Width: 49.21 ft (15 m)
Height: 14.44 ft (4.4 m)
Power: 1 x Turboshaft engine driving a two-bladed main rotor and two-bladed tail rotor.
Speed: 316 mph (508 kph; 274 kts)
Operators: United States (retired)
The classic Bell Huey helicopter went on to become the workhorse of the West throughout the Cold War period (1947-1991) and many offshoots of this successful design continue in service today (2017). Back when the Huey product was still in its relative infancy, the company teamed with the United States Army to test the limits of high-speed rotorcraft through a combination powerplant arrangement. An early-model Huey was outfitted with wing mainplanes and fuselage-mounted jet engines for added propulsion to become the Bell Model 533 - also known as the "High Performance Helicopter".

Bell Helicopter satisfied the U.S. Army requirement for the project and the two teamed up to bring the Model 533 to fruition in August of 1961. The developmental YH-40-BF helicopter, one of the six pre-series Hueys to be built, was selected as the primary specimen for the project. Beyond streamlining the helicopter's fuselage for aerodynamic efficiency (including modifying the rotor blades) there would be notable additions to its base design including the installation of wing mainplanes (eventually swept back) and turbojet engines, the latter to provide auxiliary forward thrust to help increase overall speeds. Internally, several changes also occurred in the way the helicopter was constructed and assembled to further strengthen the already versatile design for the rigors of high-speed flying.

The revised Huey aircraft then took to the skies for the first time (though sans its jet powerplants) on August 10th, 1962. In October of 1963, testing with the turbojet engines in place was begun and the aircraft managed speeds of 214 miles per hour. The U.S. Army and Bell completed their commitment to the project in April of 1964 but Bell continued with the Model 533 for a time longer - introducing the J69-T-29 turbojet engines of 1,700lb thrust to bring the helicopter to speeds of 236 miles per hour and, later, speeds of 250 miles per hour. Before the end, the aircraft was outfitted with Pratt & Whitney JT12A-3 engines of 3,300lb thrust output (each) to which point, in April of 1969, the aircraft flew at its maximum tested speed of 316 miles per hour.

Only this single Model 533 was ever constructed for the program and it was given to the United States Army Aviation Applied Technology Directorate to be displayed outside at Fort Eustis, Virginia.



Variants / Models

• Model 533 - Base Project Designation
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