Sikorsky-Boeing Defiant-X High-Speed Helicopter | The Defiant-X Helicopter is a Development of the SB-1 Defiant High-Speed Multi-Purpose Helicopter Demonstrator.
Sikorsky-Boeing Defiant-X High-Speed Helicopter
MilitaryEzyInfo.com – A consortium of U.S. companies Sikorsky (part of Lockheed Martin) and Boeing on January 25, 2021, officially unveiled the design for a new high-speed helicopter Defiant-X, offered for bidding under the Future Long-Range Assault Aircraft (FLRAA) program to create an advanced multi-role helicopter for the U.S. Army to replace the Sikorsky UH-60 Black Hawk family of helicopters after 2035. The Defiant-X helicopter is a development of the SB-1 Defiant high-speed multi-purpose helicopter demonstrator, which has been undergoing flight tests since March 2019.
Recall that the creation of SB-1 Defiant (brand name Sikorsky S-100) was carried out by a consortium of Sikorsky and Boeing as a demonstrator of the future high-speed helicopter on a competitive basis in the U.S. Army Joint Multi-Role (JMR) Technology Demonstrator (TD) program to develop a new helicopter concept to create a family of advanced military helicopters Future Vertical Lift (FVL). The presentation of the first and so far only built prototype SB-1 Defiant demonstrator (serial number 0001, registration number N100FV) took place on December 26, 2018. The first flight of the SB-1 Defiant took place on March 21, 2019, at the airfield of the American company Sikorsky (part of Lockheed Martin Corporation) in West Palm Beach, Florida.
The SB-1 Defiant helicopter uses a new loader scheme developed by Sikorsky, which combines co-axial counter-rotating main rotors with a tail pusher propeller, driven by the main rotor gear. This scheme was tested by Sikorsky on the experimental helicopter X2, which was tested in 2008-2011 and reached a maximum speed of 460 km/h, and on the demonstrator tested since May 2015 S-97 Raider 5-ton helicopter, which has a “passport” maximum speed of 444 km/h and cruising – 407 km/h.
The first SB-1 Defiant prototype is claimed to have a maximum takeoff weight of 32,000 pounds (14515 kg) and a seating capacity of up to 18 people. The SB-1 Defiant prototype is powered by modified Honeywell T55 turboshaft engines with a takeoff power of approximately 4,000 hp (these engines are used in helicopters). (These engines are used in the Boeing CH-47 Chinook helicopters), which will provide a cruising speed of at least 250 knots (460 km/h). However, according to the statement Sikorsky, the required FLRAA range will be achieved only on the SB-1 Defiant in a series configuration with advanced turboshaft engines created by General Electric Corporation under the U.S. Army Future Affordable Turbine Engine (FATE) program and having a takeoff power over 5000 hp. Apparently, in fact, such a helicopter should become Defiant-X.
The Defiant-X, like the SB-1 Defiant, is based on a combination of coaxial main rotor and tail rotor. The Defiant-X has a modified and more ‘tapered’ fuselage shape, new nose wheel landing gear, redesigned turboshaft exhaust system to reduce infrared signatures. It is also reported that the helicopter will be equipped with an electric remote control system with the ability to switch the machine to unmanned mode.
The SB-1 Defiant, like the Defiant-X now, is being built as part of the U.S. Army’s Capability Set 3 (Assault) / FVL-Medium subprogram requirements, now referred to as the Future Long-Range Assault Aircraft (FLRAA), envisioning carrying 12 fully equipped infantrymen at a cruising speed of at least 230 knots (about 428 km/h) to a range of at least 229 nautical miles (424 km), with the goal of replacing the main US multi-purpose Sikorsky UH-60 Black Hawk family of helicopters after 2035. The FLRAA helicopter is to be equipped with two advanced turboshaft engines under the FATE program.
The FVL program has been underway since 2004 and calls for five types of new helicopters or vertical takeoff and landing aircraft to replace the entire U.S. Army helicopter fleet (OH-58, AH-64, UH-60, CH-47) starting around 2035.
In 2013, the U.S. Army selected the Bell Helicopter and Lockheed Martin consortium’s V-280 Valor, the Sikorsky and Boeing consortium’s SB-1 Defiant high-speed helicopter, and the Karem Aircraft and AVX high-speed helicopter for the first phase of the Joint Multi-Role (JMR) Technology Demonstrator (TD). The last two initiative projects fell away in August 2014, and now the competition for JMR TD is between two alliances of “giants” of the U.S. defense industry (with Lockheed Martin participating in both), which under the terms of contracts awarded in 2014 had to provide their first prototype demonstrators by the end of 2017 (this condition was met only by the V-280 Valor). In both cases, the U.S. Department of Defense is funding no more than 20 percent of the cost of the companies’ JMR TD Phase I work.
Both JMR TD Phase I projects are multi-purpose aircraft to replace the Sikorsky UH-60 Black Hawk helicopter (JMR-Medium / FVL-Medium category). At the same time, both competing groups claim ongoing development of attack versions of their vehicles to meet U.S. Army Capability Set 3 / FVL-Attack subprogram requirements (to replace the Boeing AH-64 Apache attack helicopter).
Defiant’s JMR TD competitor, the Bell, and Lockheed Martin consortium’s V-280 Valor convertible demonstrator has been in flight testing since Dec. 18, 2017.