Interesting machine, using 2 x 2,600kw gas turbines to power tip jets to turn the 130' diameter rotor at its 88rpm operating speed. Lifting capacity was 4600kg.
See short flight demo of HX-17


By comparison the Sikorsky S-64E Skycrane has 2 x 3400kw engines turning a 72' diameter rotor and lifts 9100kg. It also has a rear facing load pilot with separate controls.
The Boeing CH-47 Chinook has 2 x 3500kw engines and lifts 10900kg and is the fastest machine cruising at 300kmh.
The Russian Mil Mi-26 is the heavy lifter champion and lifts 20000kg using 2 x 8500kw engines turning an 8 blade 105' diameter rotor.