The Theory and Practice of Model Aeroplaning Part 14

CHAPTER XIII.

MODEL FLYING COMPEt.i.tIONS.

-- 1. From time to time flying compet.i.tions are arranged for model aeroplanes. Sometimes these compet.i.tions are entirely open, but more generally they are arranged by local clubs with both closed and open events.

No two programmes are probably exactly alike, but the following may be taken as fairly representative:--

1. Longest flight measured in a straight line (sometimes both with and against the wind).[48]

2. Stability (both longitudinal and transverse).

3. Longest glide when launched from a given height without power, but with motor and propeller attached.

4. Steering.

5. Greatest height.

6. The best all-round model, including, in addition to the above, excellence in building.

Generally so many "points" or marks are given for each test, and the model whose aggregate of points makes the largest total wins the prize; or more than one prize may be offered--

One for the longest flight.

One for the swiftest flight over a measured distance.

One for the greatest height.

One for stability and steering.

And one for the best all-round model.

The models are divided into cla.s.ses:--

-- 2. _Aero Models a.s.sociation's Cla.s.sification, etc._

A. Models of 1 sq. ft. surface and under.

B. " 2 sq. ft. " "

C. " 4 sq. ft. " "

D. " 8 sq. ft. " "

E. " over 8 sq. ft.

All surfaces, whether vertical, horizontal, or otherwise, to be calculated together for the above cla.s.sification.

All round efficiency--marks or points as percentages:--

Distance 40 per cent.

Stability 35 "

Directional control 15 "

Gliding angle 10 "[49]

Two prizes:--

One for length of flight.

One for all-round efficiency (marked as above).

Every compet.i.tor to be allowed three trials in each compet.i.tion, the best only to count.

All flights to be measured in a straight line from the starting to the landing point.

Repairs may be made during the compet.i.tion 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 compet.i.tors 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.

[Ill.u.s.tration: 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 pa.s.s 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 compet.i.tions 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.

[Ill.u.s.tration: FIG. 54.--THE GAMAGE CHALLENGE CUP.

Open Compet.i.tion for longest flight. Crystal Palace, July 27. Won by Mr. E.W. Twining.]

[Ill.u.s.tration: FIG. 55.--MEDAL WON BY THE AUTHOR IN THE SAME COMPEt.i.tION.]

2. Always enter more than one model, there nearly always is an entrance fee; never mind the extra shilling or so. Go in to win.

3. It is not necessary that these models should be replicas of one another. On some days a light fabric-covered model might stand the best chance; on another day, a swift flying wooden or metal aerofoil.

Against the wind the latter have an immense advantage; also if the day be a "gusty" one.[51]

4. Always make it a point of arriving early on the ground, so that you can make some trial flights beforehand. Every ground has its local peculiarities of air currents, etc.

5. Always be ready in time, or you may be disqualified. If you are flying a twin-screw model use a special winder, so that both propellers are wound up at the same time, and take a competent friend with you as a.s.sistant.