Sikorsky-Boeing SB-1 Defiant

The history of the provocative Sikorsky-Boeing SB-1

The "SB-1" (or "SB>1") is a "compound helicopter" jointly developed by longtime helicopter manufacturer Sikorsky and defense contractor Boeing. The design is being fleshed out to meet the U.S. Army's Future Vertical Lift (FVL) program, which later adopted Joint Multi-Role (JMR) requirements. The SB-1 technology demonstrator competes directly with the V-280 "Valor" under development, supplied by Bell Helicopter to meet the same high-speed, transport-oriented military requirements.

To date (January 2019), the V-280 has been able to reach speeds of nearly 320 mph and has been in active flight testing for nearly a year.

The SB-1 is part of the next generation of U.S. Army helicopters, a family of rotorcraft that can be used in a variety of battlefield roles. These designs are intended to replace the UH-60 Black Hawk, AH-64 Apache, OH-5 Kiowa and CH-47 Chinook models in service with the U.S. Army. Part commonality between new designs is also a family strength, reducing long-term maintenance and repair costs.

Finally, it is hoped that a new, more mobile helicopter force can better assist ground forces. Sikorsky and Boeing have not collaborated on a military aircraft program since the cancellation of the RAH-66 Comanche stealth light attack helicopter in the late 1990s/early 2000s.

At the heart of the SB-1 and other compound helicopters is the speed in a world where helicopters are typically flown below 200 mph. The SB-1's compound approach promises to double the range while doubling it -- which not only makes the platform faster and higher ranking, but also improves overall maneuverability and agility -- when the aircraft encounters fire or attempts to Useful when navigating in confined spaces in mountainous or urban environments. The Lockheed AH-56 Cheyenne attack platform from the 1960s to 1970s was one of the most high-profile attempts at compound helicopters on the American front, and the platform was eventually discontinued after 10 were completed.

This helicopter is detailed elsewhere on this website.

The coaxial main rotor arrangement already popular on many Russian brand Kamov models (eg Ka-50/Ka-52 "Black Shark" series) is used to provide the desired lift characteristics while maintaining overall stability to support lateral axis. The tail propeller unit provides the necessary forward thrust and provides the aircraft with a significantly increased helicopter operating speed.

Combining traditional main rotor blades with "propulsion propellers", the aircraft is known as a "compound helicopter". ".

The SB-1 prototype was unveiled at the Sikorsky West Palm Beach plant in December 2018, with ground testing scheduled for later in 2019. Due to delays in implementing the SB-1 design, the first flight, which was planned before the end of 2018, is also scheduled for sometime in 2019.

The product's design was partly influenced by Sikorsky's earlier work in the compound helicopter field - namely the "S-69" in the 1970s and the more modern "X2" (both of which are detailed elsewhere on this site).

While the Sikorsky S-97 Predator compound helicopter in development (detailed elsewhere on this page) has the same appearance and general capabilities as the SB-1 Defiant, the S-97 is made by a separate The Sikorsky developed by the design team meets the requirements of the US Army's high-speed reconnaissance and light attack platform. The Defiant is designed to fulfill a multi-role, non-direct combat role closer to the UH-1 Huey or UH-60 Blackhawk series of medium transport aircraft.

Like the S-97 Raider program, the airframe of the SB-1 is similar to that of the Sikorsky UH-60 Black Hawk transport helicopter. This puts the two pilots side by side in the front (behind the flat nose cap) in the cockpit. Aft of this location is the passenger/cargo compartment with sliding doors on either side of the fuselage. Above this compartment is an engine accessory with 2 Honeywell T55 turboshaft engines.

On this unit is a dual (coaxial) rigid main rotor assembly consisting of two independently rotating four-blade parts with crank tips. The hull then extends aft to accommodate the propulsion propeller assembly. Below the tail is the ventral housing of the tail gear.

The mass of the aircraft was supported by a forward single-wheel landing gear near the midship. The tail also maintains vertical outboard fins along the wing stubs.

Specification

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