In the Spring of 1967, at our high school flying field, Bob Gieseke showed me the latests trimming device which he said a few top flyers were starting to use. It had slotted wingtip adjustable leadouts. Each leadout was carried in a separate grommet which was inserted into adjustment holes spaced along the slot. I liked the idea of adjusting the leadouts but thought the idea could be improved on in several ways. I had just built an airplane with a movable rudder to compensate for the undesirable aerodynamic effects of gyroscopic precession. With a heightened awareness of gyroscopic precession, I could see that there was some theoretical advantage to reversing the leadouts to make the front leadout the "UP" leadout. Also Bob had papered over his slot in construction which only encouraged a reluctance to open the slot and actually experiment. Also having the leadouts individually adjustable would encourage fruitless results in trimming. Leadouts should be as close together as practical as they can also create undesired yawing moments in our stunt ships. Finally, adjustments were limited to the number of grommet holes in the slot.
Still, it was the germ of a really neat system. I just thought the slotted wingtip could be improved. First, in my configuration, the leadouts were reversed to make the front leadout the up leadout. Second, both leadouts would be mounted on a sliding carrier which would be retained in place with a locking screw. This fixed a minimum spacing between the leadouts and allowed for fine adjustment along the slot as opposed to step adjustment in holes. That fall I built my first "SLIDING BLOCK ADJUSTABLE LEADOUTS". I never claimed to have invented adjustable leadouts, not even those which used a slotted wingtip. I did claim to have, to the best of my knowledge, invented the sliding block adjustable leadout which is so popular now. I had never seen or read about, any leadout adjustment any more sophisticated than Bob's slotted wingtip.
It is entirely possible that someone did use a sliding block before me, but if it happened, I was completely unaware of it. I published a photo of my sliding block adjustment in the 1970 Bearcat article and included plans for making them. Again, I have never seen a photo clearly showing a sliding block leadout dating before mine. That same article showed plans for making my version. It goes without saying that I had also never seen a similar drawing. The photo was of a Mustang that I competed with in 1969.
Whatever may come to light, my work was original. I have still never seen a photo or drawing which predated the sliding block leadouts built in 1967, used in competition in 1969, and published in 1970.
In the 40 years since I built my first sliding block adjustable leadout, There has never been the slightest suggestion that my claims were baseless as to fact if not intention.
If Ed's leadouts were sliding block configuration, then more power to him. Stunt always improves as new ideas and concepts are added to our body of building and flying lore.
Al
You know, that line on the wingtip certainly looks like adjustable leadouts, but it could be skid marks from attempting a wing-under with not quite enough altitude;
Or maybe it is a bit of blood. Some judges stand too close to the circles;
Or maybe ED was numbering his airplanes. That was the first one and he did it laying down;
Or maybe it is a high water mark to tell when the circles are too wet to fly;
Or maybe it is an attitude reference line so Ed could tell when he is flying level.
And I'll bet this doesn't cover most of the likely possibilities.
Al
Topic: Ed Kammerer's Apollo - Adjustable Leadouts? (Read 2941 times)