The ground test of the prototype SB-1 Defiant of US Sikorsky-Boeing has begun. Helicopter design with a non-rotating coaxial rotor technology first used in the American X-2 and S-97 Raider helicopters. This helicopter was developed under the United Military Joint Military Role demonstration program. The SB-1 Defiant helicopter was designed to achieve greater flexibility and manoeuvrability than double the speed and range of existing operational helicopters. The technology and experience gained from the deployment of the SB-1 Defiant helicopter will contribute to the development of the US Army's new aggressive and helicopter within the Future Vertical Lift program, which should be put into service in the early part of the decade of 2020.