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Name:  Paul S.
Status:  educator
Age:  40s
Location: N/A
Country: N/A
Date: 2000-2001


Question:
I was asked this question by a student with an imagination regarding the force of the airflow produced by a helicoptor. Is it possible for the air flow produced by that of a helicoptor to 'suck up' (her words not mine) an adult human into the blades as it is taking off or landing?


Replies:
It would seem to me that the downward flow would prohibit this form occurring; however, smaller objects such as small rocks and dust particles may return to the turning blades with the turbulent air flow. Could an object, the weight of an adult human, also be caught up in this turbulence?

I do not expect an object with the weight and density could be "sucked up" by the helicopter blades while taking off or landing. When a helicopter is near the ground, the air pushed through the blades "collides" with the ground. The molecules have to go somewhere. The only directions are upward and outward. Air pushed upward and not too far outward may find itself above the blades, joining with the current pulled down through the blades. Dust and sand can be picked up by a strong breeze, so they can also be picked up by the air flow of the blades. A person might be knocked down by this air flow, but not lifted up. Air flow with the strength of a strong tornado would be necessary for that.

Kenneth Mellendorf


You are correct, when a helicopter takes off there is a strong down draft, so strong it would send humans running for cover. Small sticks and stones will pelt anyone nearby. Some of these could be swept up in the updraft that occurs when the air swirls back up off the ground. But a person? I do not think so.

Vince Calder



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