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Re: helicopter not equal rocket



At 11:12 AM 8/19/99 -0400, Michael Edmiston wrote:
Denker says: "I keep daring people to explain translational lift using
the helicopter-as-rocket model. Still no takers."

John, please define "translational lift" so that I am sure I know what
you're asking. Then maybe I'll give it a try.

Fact: A helicopter requires significantly less power when it is moving
(translating) than it does in the hover. This is called translational
lift. (This is the standard, if not exactly brilliant, terminology).

The effect is so significant that many helicopters cannot hover outside of
ground effect.

Hint: The physics is similar (albeit not quite identical) to what we call
induced drag in a fixed-wing aircraft.

As the saying goes, learning proceeds from the known to the unknown. It is
droll to see people who have never heard of translational lift using
helicopters to "teach" other folks about induced drag.