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Old 09-03-2011, 02:34 PM   #5
lwcamp's Avatar
Join Date: Nov 2004
Location: The plutonium rich regions of Washington State
Default Re: Flight on na-Barsoom

A few thoughts - your lift-to-drag ratio doesn't change. The ratio of the amount you go forward to the amount you sink in constant speed gliding is your lift-to-drag ratio, so you go just as far when gliding. What happens is that you sink slower, but also go forward slower. Expect soaring critters like eagles or albatrosses to be slower by the ratio of Martian gravity to Earth gravity.

Getting aloft in the first place is easier. If you are treating your flier as a fixed wing aircraft (very appropriate if it is a fixed wing aircraft, not so much if it is a bird or bird-man or pterosaur or bumblebee or something), then you equate the lift of 0.5 C_l A rho v^2 to the weight M g (where C_l is the coefficient of lift at the stall angle, A is the plan area of the wings, rho is the atmospheric density, v is the airspeed, M is the mass, and g is the local gravitational acceleration measured in units consistent with the rest of everything else and not necessarily with respect to Earth's gravity). You see that the stall speed varies as the square root of (g/rho) for a given flier. For flapping flight, you can get airborne at a lower speed than with fixed wings.

Hovering flight becomes easier. You need to exert a force equal to your weight (plus any losses due to drag), which is smaller.

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