Light rotorcraft maker Robinson Helicopter and biotechnology firm United Therapeutics recently ground tested an R44 modified with hydrogen fuel cells, and the companies say test flights are imminent.
Brazilian regulators have approved operations of US firm Rotor Technologies’ R550 Sprayhawk, marking the first such approval for the remotely-piloted variant of Robinson Helicopter’s single-piston R44 ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results