Why do helicopters make that iconic thumping sound when they're flying?

Helicopters of all sorts make that iconic, rhythmic sound of thumping in order to maintain flight and maneuver, all powered ...
HotHardware

NASA’s Next-Gen Mars Helicopter Blades Break Sound Barrier in Record Test

Ingenuity's little-helicopter-that-could proved that flight on another planet isn't just a one trick pony, but something that can be expanded upon. Enter NASA's next-generation Mars helicopter blades ...
BGR

NASA's Mars Helicopter Actually Breaks The Sound Barrier

NASA recently pushed the rotor blades of its next-generation Mars helicopter to Mach 1.08 at its famed Jet Propulsion Laboratory (JPL) near Pasadena, California. JPL is testing a high-performance ...
TechSpot

NASA's next Mars helicopters tested beyond the speed of sound

Martian Flying Objects: After successfully testing the first extraterrestrial flying object with Ingenuity, NASA is now looking ahead to the next phase of its Mars flight activities. The space agency ...