Aileron Spades Message Board

• My first spades had drooping edges on each side. As a result roll and yaw were reverse coupled. that is right rudder produced left roll and vice verce. I replaced those spdes with ones which have inboard droop only. Now yaw and roll are correctly coupled. Now, right rudder produces right roll and vice verce.

From: Archie Dunbar
dunbar@mc.net
I think it would be like this. You are flying
along in level flight with very little control pressure. You step on the right rudder, gently. The spades which were presumeably at 0 angle of attack now are at a negative angle of attack right and/or positive angle right which forces the left aileron up, right aileron down and gives left roll for right rudder.

I do not remember other spade shapes I have seen except the ones that have the small downturned flanges on each side. I wonder if adopting that shape would be an improvement.

Dick have you tried the new spades inverted? Also, what happens in spins. With the original design does the yaw produce automatic or uncommanded outspin aileron?

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From: Dick Rihn
Rihnairco@aol.com
There are two things to consider in making any rudder changes for increased control effectiveness. One is the amount of rudder pedal travel required for full deflection and the other is the amount of muscle power required for full deflection at various speeds. Again this is a very great variable. The most classic example is the Sabre owned by Cecilia Aragon. She purchased the project from Rory Moore (6'2"/230lb) and (guessing) Cecilia is 5'0"/100lb. Rory thought the rudder was great. Celia couldn't make it move properly. So she mounted spades on each side. The moment arms are connected to the leading edge of the rudder. This is another area of individual taste. I have modified my rudder control set up by moving the attach point of the cable inboard at the rudder horn and raising the attach point of the cable upward on the rudder pedal. What I was seeking was less motion and was/am willing to put up with a little more muscle requirement. Since I weigh 200lb I think my leg can handle over 100lb. of force. Other pilots would like to have equal forces on all controls at all times regardless of maneuver etc. That is what makes the world go around. Decide what you want and build it into the aircraft. That is the beauty of building your own!

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From: Dick Rihn
Rihnairco@aol.com
I can find no difference in performance with my new spades except in level flight where it is a great benefit and in the initation of snap rolls and spins. Before I was having to use aileron to offset the unwanted forces of the first set of spades. Spades are a very personal thing. What is desired by one pilot may not be desired by others. Some 1-D owners prefer to not have spades and some like them to be so big they are almost at the aileron snatch level. To each his own. That is the great beauty of building your own aircraft.

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From: Dick Rihn
Rihnairco@aol.com
I had trouble understanding this too. I finally spent time kneeling down at the traling edge of one wing. I then tried to visualize the effect of a side slip on the spade. I put my hand on the drooping portion of the spade and pushed in what I would assume would be the direction of airflow. This deflected the aileron. With a double droop (flange on each side of the spade) apparently there is enough interference that the effect is reversed from that found with a single inboard droop. My aircraft has now been trimmed so that at cruising speeds it flies hands and feet off, straight as an arrow for more than ten miles at a time. However, it still retains its 360 degree per second roll rate. It sure beats the heck out of all my previous mounts.

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From: Dick Rihn
Rihnairco@aol.com
I have accumulated more hours on the new spades which have a droop on the inboard edge, only. I am extremely happy with these ailerons. They are the best that I have ever flown! I have recently checked out in an Extra300/200 in order to teach aerobatics. It is a wonderful airplane also but the spade/aileron combination is only a little better than my Pitts S 1T and not even in the same league as my One Design. Try the inside droop. I like flying to and from the practice area with my feet and an occassional tweak on the stick for pitch control. I have moved up to vertical ascending snap rolls and tumbling figures. This is one incredible machine. At first I had trouble with the vertical ascending snaps. then I tumbled to the reason. I was carrying too much speed on entry. Imagine that luxurious capability to draw a line before the snaps). Couldn't happen in the Model T.

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