Symmetrical Airfoil Tails

[tonydenton]

echo what is under the left side of your spar,where did you get it and how is it mounted,

[Echo]

Tony,
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[asra]

I"m pretty sure Rosco said you need about 30% more area for a plate airfoil compared to a streamlined one - to have the same affect.That"s for gyro speeds of course The plate tail on my gyro is enough to wag the dog on hot days alright BadenThe only real inefficiency"s occur when the relative airflow changes in flight. These changes occur in the pitch or yaw plain, due to weather, power changes, and control input etc. Both our HS and fin/rudder are tasked with the job of ensuring our machine always point in the relative airflow. When airflow hits eather surface from an angle or side the surface will produce a lifting force due to its angle of attack, re aligning the machines in to the relative airflow, like a weather ****. The main difference between a flat plate and an aerofoil section tail is the stall angles. A flat plate usually stalls at about 5 degrees, were as an aerofoil section usually stalls at about 15 degrees. So if airflow hits a flat plate at more than 5 degrees it will not produce the correcting force required, but instead it produces drag. The drag will still help fix the upset, but is no were as effective or efficient. This is similar to how the tail of a kite works. The drag of a stalled flat plate will also effect the machines performance in climb, fuel burn, and general maneuvering.My 2 bob Regards SamL..............