From Harvey Swack
P.O. Box 615
Needham Heights, Massachusetts 02494
http://www.greatairplanes.com

 December 19, 2006

Builders of Barney Oldfield Aircraft designs were offered the choice of the tear drop aileron or the Frieze type.  A letter from a builder of a Super Baby equipped with Frieze ailerons has commented that the ailerons are stiff at higher speeds.  If this is the case with your airplane you will have to install spades to improve the roll rate and make them lighter.  When we designed and tested the Frieze aileron we did find some improvement by did not redesign the aileron control system to provide differential ailerons.  We did not intend this airplane to be used for serious aerobatic competition and we did not want to make the control system more complicated.

I asked Dick Lane to comment on this matter and here is his reply:
Barney Oldfield rigged the wings to provide the maximum stability to assure that no matter whatever altitude the airplane got into (upright or inverted) (by design) pilot induced or accident, it would right itself if the throttle was closed and hands and feet were off the stick and rudder pedals.  That assumes that there was enough altitude left to recover before meeting the ground!

This stability is achieved by two things:
1. Dihedral on the top wings and

2 . More than 1 degree more incidence than the bottom wings.

 This caused the airplane to have all the weight in straight and level flying to be carried in the top wings.  Note; the sweep back of the top wings multiply the dihedral effect.  The bottom wings go along for the ride, contributing little if any lift, at cruising speed, straight and level.  Aileron input caused induced drag on both bottom wings which tends to multiply as more and more stick input is added.  This way of rigging nearly nullifies inverse yaw in roll maneuvers making it possible to do aileron rolls with out  (if any ) rudder input.  But the induced drag makes for heavy aileron stick forces which get heavier the faster and/or greater stick deflection.

Now what to do about it.
1. Reduce the resistance to the roll by taking all the dihedral out of the top wings.  There will still be some lateral stability, due to the sweep back.  

2. Add Spades to the bottom of each aileron inboard rib (it is the strongest) the Frieze ailerons do very little to lighten the stick force since there is equal aileron deflection on both. They are very effective when rigged differentially. But that will cause inverse yaw!  Remember everything on an airplane is a Compromise!

Caution: The reduction in inherent stability will increase the time (and the need for altitude) to recover from unusual attitudes that are not under full control.

Everyone owning, building or even thinking about building and flying one of these wonderful airplanes should understand that quality of engineering that went into this design!


Happy Holidays and Fly Safe,

Harvey Swack