All flights to be measured in a straight line from the starting to the landing point.
Repairs may be made during the competition at the direction of the judges.[50]
There are one or two other points where flights are not made with and against the wind. The competitors are usually requested to start their models from within a given circle of (say) six feet diameter, and fly them in any direction they please.
"Gliding angle" means that the model is allowed to fall from a height (say) of 20 ft.
Fig. 53.—Model Designed and Constructed by the Author for "Greatest Height."
A very lightly built model with a very low aspect ratio, and screw giving a very powerful dynamic thrust, and carrying rather a large amount of rubber. Climbs in left-handed spirals.
"Directional control," that the model is launched in some specified direction, and must pass as near as possible over some indicated point.
The models are practically always launched by hand.
§ 3. Those who desire to win prizes at such competitions would do well to keep the following points well in mind.
1. The distance is always measured in a straight line. It is absolutely essential that your model should be capable of flying (approximately) straight. To see, as I have done, model after model fly quite 150 to 200 yards and finish within 50 yards of the starting-point (credited flight 50 yards) is useless, and a severe strain on one's temper and patience.