I have all of my F3A experience here in Europe. Europe, I believe, started the trend of slower flying and I have seen it taken to the extreme. In Romilly, however, I noticed that Qui-Que, Christophe, Marco, and Wolfgang (the top four, no it that order) all kept more throttle in than most. Marco flew the Angel's Shadow in Romilly which is a good deal more slippery than his new Supreme. They flew with relative quickness compared to most of the field. Too slow is a major cause of mushy, uncrisp manuvers. To fast, well, no time to think, snap become less controllable, and corner radiai become to large.

On constant speed, there is a notion here that I have not yet found in the rule book. Although it adds to precision if you are a counter (1,2, roll, 1,2, push), a geometrist uses the artificial horizons visualized mentally as another way to center the figures. Although I understand the judges have particular tastes, I do not find constant speed in the rules, thereby, according to me, only the geometry and not the speed of the figures should be judged. That said, the new airplanes with fat fuses, thick profiles, and parasitic drag here and there manage quite well to keep a constant speed to compliment the trend. Yes, I too am trying to become an expert at constant speed.

Like anything, now, the speed at which an airplane flies is a synergistic principle of drag, wing loading, and propellor selection. I will separate my major areas with paragraphs only to be more clear.

Drag is created in several major areas.

Although fuselage width does not play a great factor, the radius of the curve from the nose to the sides of the fuselage does make a large difference. Then there is total skin area, although at the lower speeds this too is minimal.

A huge and often overlooked drag factor are the thicknesses of the trailing edges of the wing, stab, and rudder . Thicker TEs add great amounts of drag.

As far as wind affecting the flight goes, actually the wing geometry and airfoil design have more of an effect in this than the fuselage side area. Remember that pressure on both sides of the fuselage are equal when the aircraft is following a constant flight path. More side area is getting hit by the windward side, but there is the same side area on the leaward side so the effects balance out. Side area balance between the nose and tail of the airplane is quite important in this respect.

The gear add a little bit, the ductings and cooling holes add a little. The further back along the fuselage, the less the effect these little pieces have.

Yes, wing loading has a very significant effect, especially on downlines. It's a little bit bizzare, but draggy airplane fly faster with higher wing loadings (see gravity) and racing airplanes fly slower with higher wing loadings (see angle of attack in regards to lift induced drag). OK, this is greatly simplified and much here depends upon the flight attitude, but always shoot for lighter. We have not yet found the point where the airplane is too light.

Then, of course, there is the propellor. Pitch is effective in pulling the airplane uphill, and the slow spinning prop slows the airplane on the downlines. Prop braking loses all effects when the airplane slows or goes below the speed at which prop thrust velocity equals the airplanes airspeed (hence, killing the motor will shorten the rollout).


There are some ideas from this peanut gallery.

Cheers all and fly greatly!!!

Mark