The K-MAX is the world's first helicopter designed and certified for external lift operations. More from Tech The Kaman K-MAX has intermeshing rotors eliminating the need for a tail rotor.

Obviously there are a great many differences between attack helicopters and fighter jets ... Those main rotors also negate the need for a tail rotor, which is especially helpful in instances ...

Lockheed Martin subsidiary Sikorsky has successfully flown an electric-powered, 115-lb (52-kg) autonomous drone that uses ...

Lockheed Martin's Sikorsky has successfully flown its "rotor blown wing" drone in both helicopter and fixed-wing flight modes ...

Between the abbreviated fuselage and the tail, [Arron] installed a tail rotor from an 800 size helicopter. A 1.25 kW brushless motor drives the tail rotor while a high-speed servo controls the pitch.