Jim,

 

For comparison, what is your empty weight CG location and do you have full elevator authority at full flaps?

 

Also, remember that the horizontal stab is providing negative lift (flying upside down).  So, in level cruise flight, your H. stab has less angle of attack than mine.  It would be interesting to know the stick force necessary to keep the nose from rising at say 175 KIAS when the elevator is trimmed to the neutral position.  Ah, never mind as there would be differences with different trim systems, elevator bell crank length, etc. 

 

Scott

 

Scott, I didn’t think that would work (having the elevator on) until I did the same measurements and calculation. I first did mine without the elevator attached, dividing the cord thickness in half then measuring the waterline to leading edge. I got -.82º to -.95º depending on how well you can interpret the meniscus. So I measured with the elevator on and got -.59º  to -.67º. Close enough.

 

I guess this means that my elevator has a slight downward deflection from the fixed portion.

My dimensions were 21.25 at 12 inches in from the counter balance cut. The waterline difference was .25 inch to .22 inches depending on how well you read the meniscus.

I’m glad I did this re-measurement as the longer I thought about it the more convinced I was I did it wrong when I set the HS.

Jim

 

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From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Sky2high@aol.com
Sent: Monday, October 06, 2008 8:35 AM
To: lml@lancaironline.net
Subject: [LML] Small Tail Incidence Data

 

 Here are the results: