why? when walking around and helicopter do you have to duck down?

Question

when the helicopter is running .

Answer 1

Depending on how tall you are and what kind of helicopter you are speaking of, you may not have to duck. I flew helicopters in Vietnam and the only grunts that had to be careful getting on or off a UH1 Huey were the radiomen with their long whip antennas. Of course regardless of the nine foot height of a Huey's blades, they had other reasons to duck. That tail rotor can be a killer though.

Oh yeah. The above comment about being sucked up into the blades? Can't happen. The blades produce a downward force, never upward that could suck you up. That's how they work in the first place; by producing downward thrust so they can leave the ground. I suppose they could suck somebody up if they could hover upside down but of all the stupid things I did when I was young, I never tried that one.

Answer 2

It seems John B had the most sane answer to the question. I would like to expand on this also.

Another thing you must consider is habit patterns. people that operate around helicopters should form good habits. Crouching while walking away from a helicopter is a good thing. here's why...If you spend most of the day working underneath a Bell 206 you might not have any problem walking straight up, however when it's time to load up on an S76 you walk up from the front and your life just ended. The blades on an S76 are tilted down in the front, much like many other wheeled helicopters. Several people have been decapitated due to this very event. Good habits should be practiced all the time even when it might not be 100% necesary.

Answer 3

To prevent getting a very bad haircut. Seriously though, on most helicopters, the rotors are higher than most people heads. But if the helicopter has landed on a slope and/or the pilot has cyclic input toward the slope, the rotors could be low enough to do some damage to any unsuspecting heads.

Even when you know the rotors are high enough to walk under, most people will duck anyway because getting a bad haircut can really ruin your whole day.

Answer 4

It's mostly psychological, since most rotor systems are located well above the average human's head. However, when you've got a wing flying around at a couple of hundred MPH just a few feet above your scalp, you duck.

It is possible, depending on the helo, if the pilot idles down and/or moves the cyclic, to get the blade tips low enough to impact a person. That will ruin your afternoon.

Probably more dangerous than not ducking under the main rotor is the tendency to walk into the tail rotor. In a bit of gallows humor, we used to call the people who did that (and usually bought the farm doing so), Ensign Rotorbrake.

Answer 5

The main one is to keep the rotor blades from taking your head off. When helicopters land, they land on level ground. Care must be taken when leaving the helicopter not to exit toward an upslope, where you may come in contact with the blades. On flat level ground, you would not normally contact rotor blades. However, a lot of pilots "idle down" when sitting, which allows the blades to droop. The change in height can decapitate an unsuspecting person.

Answer 6

Ducking - from someone who flies on helicopters regularly, I can tell you several reasons.

The main one is to keep the rotor blades from taking your head off. When helicopters land, they land on level ground. Care must be taken when leaving the helicopter not to exit toward an upslope, where you may come in contact with the blades. On flat level ground, you would not normally contact rotor blades. However, a lot of pilots "idle down" when sitting, which allows the blades to droop. The change in height can decapitate an unsuspecting person. A person I worked with once saw it happen.

Another reason is, indeed to keep objects from being drawn into the blades or tail rotor.

Answer 7

Because the propeller blades,on top of the helicopter while spinning, sags towards the pavement of the helicopter pad. Therefore those who are boarding or leaving the aircraft must duck down, otherwise they get their heads chopped off.

Answer 8

the reason a person ducks when walking around a helicopter when the blades are turning is so they don't get their head chopped off.
large helicopters with the blades turning fairly fast will not require you to duck . but a small helicopter does .
see with any of them the engine could stall and then the blades would slow and lower enough to chop off your head.
it does happen from time to time

Answer 9

well, as you may have noticed, a helicopter has popellers that move in a circular motion above the fuselage which allows it to generte the necessary lft in order to fly. Those propellers are moving very fast, and could easily remove any limbs or heads which come in contact with them (just ask Dr. Romano on ER), so therefore it is usually a good idea to duck so as to be certain not to contact one of those propellers.

Answer 10

you dont have to. its human nature to duck away from things that could possible cut you're head off, even if its ten feet above the ground