Helicopter Rotor Clearance When Landed

It seems that people tend to underestimate the clearance between their heads and the whirling main rotor of a landed helicopter.

Every helicopter I've ever stood next to has plenty of clearance over the heads of even tall people standing erect, and I'm 6' 2".

On every episode of M*A*S*H, you see the surgeons and nurses almost doubled over when approaching the chopper bringing wounded to the field hospital.

This really looks dumb!

H.P.

 

Here is one reason....


Here is a basic answer without getting too into helicopter aerodynamics/systems:

In order for helicopters to move forward, backward, and side-to-side the rotor blades are always changing pitch, moving up and down, or moving forward and backward. Due to the speed of the rotors, these movements can be difficult for people to see. At times the blades can teeter totter on the engine shaft (imagine the engine shaft as a fulcrum). This means that the tips of the blades can actually be lower to the ground than normal when they swing around to the front of the helicopter, and be higher when they swing around to the back.

Depending on the size of the helicopter (like a smaller one that is low to the ground), people have been known to get decapitated by helicopter rotors because the pilot wasn’t aware that they were approaching. The pilot has to know that people are approaching so that he/she can adjust the blades to where they aren’t swinging too low to the ground.

 

thank you.

Hal

 

That wasn't my answer....it was an official answer.

 

Of course! Who else?