In a recent test, the Sikorsky-Boeing SB>1 Defiant prototype helicopter lifted an external load representing a tracked guided-rocket launcher.
The “mission-relevant” demonstration involved moving a 5,300-pound (2,400 kilogram) training load, which stood in for a U.S. Army guided multiple-launch rocket system (MLRS). That weight also equates to an infantry squad vehicle or hundreds of thousands of rounds of ammunition, according to Sikorsky.
The flight took place last week at the Sikorsky Development Flight Center in West Palm Beach, Florida. In a short video posted online by Team Defiant, Defiant is seen hovering above and then lifting the training load using only its coaxial counter-spinning main rotors. The aircraft does not engage its pusher propeller or move from a hover with the load, slung from a lengthy tether, held steady off the ground.
Defiant is the experimental prototype on which Sikorsky and Boeing are basing the Defiant X, their pitch for the Army’s Future Long Range Assault Aircraft. The 30,000-pound (13,607 kg) class Defiant X is advertised as having a carrying capacity of 12 troops, or 3,680 pounds (1,669 kg) of cargo.
Defiant’s FLRAA competition is the Bell V-280 Valor advanced tiltrotor, which also can carry a dozen troops. Bell says Valor, which demonstrated sling load testing at an undisclosed weight in December 2020, has a useful load of 12,000 pounds (5,400 kg). After more than three years of continuous flight test, Bell grounded the V-280 in June.
FLRAA will eventually replace the UH-60 Black Hawk, which can carry 9,000 pounds (4,080 kg) of supplies as an internal or external load at a maximum gross weight of 22,000 pounds (9,979 kg).
Both Defiant and Valor arose from the Joint Multirole Technology Demonstration (JMR-TD) program that saw each operational prototype amass significant flight time and demonstrate speed and agility beyond the reach of conventional rotorcraft. In May, Defiant exceeded 230 knots in level flight. Valor has flown at 300 knots. Both teams received an official request for proposals in early July and are expected to pitch FLRAA aircraft based closely on their prototypes, as Sikorsky and Boeing have done with Defiant X.
A winner will emerge in the second half of fiscal year 2022, which begins Oct. 1. The victorious FLRAA manufacturer will then have until mid-2026 to begin delivering aircraft, according to a program schedule laid out in the Army’s budget documents for fiscal year 2022. A total $448 million has been set aside in that budget for ongoing FLRAA development.
