Ordinarily on a helicopter, the main (top) rotor is mechanically linked to the tail rotor, so the spinning of the former causes the latter to do likewise. An experimental new system replaces the tail ...

Helicopters have always looked like the scariest way to fly, with not one but two large and menacing rotors spinning at deadly speeds. Although one of them is probably too high to chop your neck off, ...

So I just bought this nice new switch off Ebay for cheap and it has 4 very loud fans in it. I'd like to replace them with lower noise (and lower flow, I'll take my chances) fans so I can hear myself ...