Monday, May 25, 2009

Touchdown Autorotation



People wonder what happens when the engine quits on a helicopter. The answer is the same as with an airplane - you glide to a landing. The mechanism is a little different since the "wings" on a helicopter move a bit faster than the crew does. So when the engine quits we set the controls to allow the wind coming up through the rotor to spin it like a windmill. As we get to our landing spot we flair (nose up) to slow the helicopter down, and as it settles we increase the pitch of the rotor blades to cushion the touchdown. The above video is me with the schools Chief Flight Instructor practicing a touchdown autorotation. By the start of the video I've already set the engine to idle and have established a glide. I'm about half way through a 180º turn to line up with the runway. Most of the sound you hear is coming from the tail rotor. At about 40 feet above the ground you can see the tail drop in the flair, these as the helicopter settles I level the skids and you can hear the rotor slow down as I cushion the touchdown.

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