My bad, that is the correct word.

First off, in post 9, I said that a 50 foot is overly tight, so it is a slightly smaller radius than should be used, though every pylon model can achieve it without breaking. Most racers do turn tighter at pylon 1 than at the 2-3 turn.

If you are flying the course in the States, the distance between pylon 2 and 3 is 100 feet. The smallest radius and shortest course length that allows one to smoothly fly 2-3 in a single turn is approximately a radius of 71 feet. This gives a g loading of about 27 g in calm wind. However to avoid traffic, it is best to be able to turn inside of a leading aircraft to avoid wake turbulence. To do this decreases the radius of the turn.

Now if you increase the speed to 190 mph, which is another class of racing, and do that same 71 foot radius turn, you end up with a loading of 34g. A tighter turn at pylon 1 of 60 ft radius and you have a loading of 40.3 g. So you can easily see that loading on a fast pylon model can be quite high.

When I was racing 5 lb. Formula One models, they went around 175 mph on the course. After a crash where the wings were only slightly damaged, I would subject them to the following test. I would support the wings on a pair of blocks that were 46” apart and would stand on the center section. I weighed 170 at the time, and never had a wing fail in the test. You might observe that a 5 lb. airplane at 40 g’s would require up to 200 lbs. of force. However, the weight of the wing is distributed, so it does not concentrate at the center section. Removing 20 oz of the wing, but adding 8 oz for the fuel removes ¾ lb. for a total of 4 ¼, so at 40 g, you end up close to the 170 lbs. of my test. At one contest, about 20 % of the airplanes folded their wings to due high winds that were quite gusty. The wings collapsed in the turns when the airplanes experience a gust that changed the instantaneous angle of attack of the plane.

I have an engineering degree. Engineers live and die with numbers and calculations. When the numbers are right, people don’t notice. When they are wrong, airplanes have structural failures, bridges fall to the ground, and buildings collapse.

Did you every hear of the Rolling Airframe Missle? It was an air to air missle designed to be a lifting body, so that it could pull 100 g's in it's final moments to impact the target. While maned vehicles are limited to far less g loading, due to their slower speeds they can be hard for a missle to hit when they jink correctly. The RAM was designed to match that tighter radius at a much higher speed, thus requiring the increadible g loads.