- Reaction score
- 63
- Points
- 530
The two designs that are being considered are evolutionary a tilt rotor design and a traditional design by Sikorsky-Boeing with pusher prop.
http://www.nextbigfuture.com/2016/12/prototypes-for-vehicles-to-replace.html
The Sikorsky-Boeing entry, called the SB-1 Defiant, is a compound helicopter design with co-axial rotors and a pusher-propeller. The aircraft is based on Sikorsky’s revolutionary X-2 design that was designed to overcome the 200-knot speed limit of most helicopters as a result of a phenomenon called the dissymmetry of lift. It is to fly in 2017 and will be evaluated by the Army for further development. Sikorsky is leading the development of phase one with an aircraft based on their previous Sikorsky X2 design. The design will have a cruise speed of 250 kn (290 mph; 460 km/h), but less range due to using the "old" T55 engine. A new engine (the future affordable turbine engine (FATE) like on the V-280) would meet the range requirement of 229 nmi (264 mi; 424 km) Compared to conventional helicopters, the counter-rotating coaxial main rotors and pusher propeller offer a 185 km/h (115 mph) speed increase, combat radius extended by 60%, and performs 50% better in high-hot hover performance. Sikorsky has said that the X2 design is not suitable for heavy-lift size, and instead suggests the CH-53K for heavy-lift and tiltrotor for the ultra-class. However, Sikorsky plans to build the 30,000 lb-class JMR-TD (with a cabin 50% larger than the Black Hawk) at full scale to remove doubts about the scalability of the X-2 technology.
http://www.nextbigfuture.com/2016/12/prototypes-for-vehicles-to-replace.html
The Sikorsky-Boeing entry, called the SB-1 Defiant, is a compound helicopter design with co-axial rotors and a pusher-propeller. The aircraft is based on Sikorsky’s revolutionary X-2 design that was designed to overcome the 200-knot speed limit of most helicopters as a result of a phenomenon called the dissymmetry of lift. It is to fly in 2017 and will be evaluated by the Army for further development. Sikorsky is leading the development of phase one with an aircraft based on their previous Sikorsky X2 design. The design will have a cruise speed of 250 kn (290 mph; 460 km/h), but less range due to using the "old" T55 engine. A new engine (the future affordable turbine engine (FATE) like on the V-280) would meet the range requirement of 229 nmi (264 mi; 424 km) Compared to conventional helicopters, the counter-rotating coaxial main rotors and pusher propeller offer a 185 km/h (115 mph) speed increase, combat radius extended by 60%, and performs 50% better in high-hot hover performance. Sikorsky has said that the X2 design is not suitable for heavy-lift size, and instead suggests the CH-53K for heavy-lift and tiltrotor for the ultra-class. However, Sikorsky plans to build the 30,000 lb-class JMR-TD (with a cabin 50% larger than the Black Hawk) at full scale to remove doubts about the scalability of the X-2 technology.
