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General control line discussion => Open Forum => Topic started by: Kim Mortimore on January 24, 2011, 08:52:25 PM

Title: Overhead line tension and air density
Post by: Kim Mortimore on January 24, 2011, 08:52:25 PM
Does it make any sense that a plane with lots of overhead tension in cold, dense air would have less in warmer, drier air, all else being equal?
Title: Re: Overhead line tension and air density
Post by: Tim Wescott on January 24, 2011, 09:12:51 PM
Yes, but any engineer worth his salt knows the difference betweens "makes sense" and "is".

(I.e., you gotta test that theory).
Title: Re: Overhead line tension and air density
Post by: Bill Little on January 25, 2011, 10:10:39 AM
Does it make any sense that a plane with lots of overhead tension in cold, dense air would have less in warmer, drier air, all else being equal?

Hi Kim,

If nothing else, the engine is making more power in the cooler, denser, air. ;D

Big Bear
Title: Re: Overhead line tension and air density
Post by: Randy Powell on January 25, 2011, 10:50:07 AM
We used to fly in Idaho in the summer. 3000 or so feet sea level, 100+ degrees, about 6% humidity and dead calm. We used big props and very large venturi and lots of fuel. We'd go to Seattle for a contest: 65 degrees, a bit of breeze, humidity in the 60s or so and of course, at sea level. It was incredible the difference in how the planes handled and the difference in fuel load needed.
Title: Re: Overhead line tension and air density
Post by: Dick Pacini on January 25, 2011, 10:57:01 AM
Those guys flying in Australia have an advantage in the overheads.  Of course, level flight requires constant down control to maintain the 5' altitude. LL~ LL~ LL~ :##
Title: Re: Overhead line tension and air density
Post by: Larry Fernandez on January 25, 2011, 02:01:24 PM
Does it make any sense that a plane with lots of overhead tension in cold, dense air would have less in warmer, drier air, all else being equal?

I don't know Kim, 55 degrees last week to 65 degrees on Sunday.
Ten degrees at sea level doesn't seem to bee much of a spread. I know I have never had any line tension issues in reasonable temperature changes.

Larry, Buttafucco Stunt Team