Convair Model 49
| Convair Model 49 | |
|---|---|
| Type: | Ringwing , attack helicopter |
| Design country: | |
| Manufacturer: | |
The Convair Model 49 was an unrealized design of a ring-wing aircraft , also called a ring-wing aircraft or coleopter, which was designed as part of the Advanced Aerial Fire Support System (AAFSS) program.
technology
The most unusual proposal in the AAFSS competition came from Convair's San Diego Division. The Model 49 didn't fit the normal shape for an airplane or helicopter and was something completely new. The driving power comes from shaft drives that drive counter-rotating ducted propellers. Convair believed the system was more reliable than a traditional helicopter, and indicated that the only pilot inputs were directional control and setting the rotor blade angle and engine speed. The two-man crew occupied a movable capsule equipped with a number of sensors on the rotor casing. The engine, fuel, crew capsule and avionics bays were equipped with two-layer steel protection to protect against a 12.7 mm projectile.
Like a helicopter, the ring wing was able to take off, land and hover vertically. The propulsion system consisted of three Lycoming LTC4B-11 shaft turbines, although General Electric T64 , Allison T56, and Pratt & Whitney JFTD12 engines were also examined. The motors were coupled by clutches, shafts and reduction gears with counter-rotating rotors with variable inclination in the fairing. The casing increased the thrust under certain conditions and compensated for the relatively small diameter of the rotors. The motors and gears were in three of the nacelles on the sides of the casing; The fourth nacelle contained the weapons and avionics. The overall control system was believed to be similar to conventional helicopters. Convair planned to leverage the experience of the Navy XFY-1 Pogo program in vertical control systems and engine installations and believed the development risk was low.
equipment
A variety of weapons have been suggested for use on the Model 49. The normal armament consisted of two side turrets with either XM-134 7.62 mm machine guns or XM-75 40 mm grenade launchers. Each turret was fitted with either 12,000 cartridges of 7.62 mm ammunition or 500 40 mm shells. In a central tower was a 30-mm XM-140 cannon with 1000 rounds of ammunition. 500 WASP missiles or a second 30 mm cannon could also be mounted on the middle tower. Each of the turrets could be rotated and raised, and could be fired at high speed while sitting on the ground, hovering, or flying forward. Mechanical limiters were provided to prevent any of the guns from shooting at the nose of the crew compartment when moved forward / down. There were four weapon pylons on the four engine nacelles (which also contained the landing gear). Each could carry a fuel tank, three BGM-71 missiles, or three Shillelagh missiles. Alternatively, one of these weapon pylons on each nacelle could carry a single M40A1C 106mm rifle with no recoil and 18 rounds of ammunition. The 106mm cannon had an effective range of 10,000 yards and was effective against armored targets. All weapon pylons could rotate so that they could be pointed into the wind during high-speed flight, or could be fired when flying forward or hovering. Four external fuel tanks provided up to 1200 gallons of additional fuel for transfer flights.
Convair chose the ring wing design for its Model 49 proposal as part of the Advanced Aerial Fire Support System (AAFSS) program. However, the US Army chose the conventional concepts of the Lockheed AH-56 Cheyenne and Sikorsky S-66 as the winner of the competition.
Web links
literature
- Robert E. Bradly: Convair Advanced Designs II , Specialty Press, ISBN 978-0-85979-170-0