MODEL FLYING COMPETITIONS.
§ 1. From time to time flying competitions are arranged for model
aeroplanes. Sometimes these competitions 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 classes:--
§ 2. _Aero Models Association's Classification, 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 classification.
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 competitor to be allowed three trials in each competition, 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 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.
[Illustration: 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.
[Illustration: FIG. 54.--THE GAMAGE CHALLENGE CUP.
Open Competition for longest flight. Crystal Palace, July 27. Won by
Mr. E.W. Twining.]
[Illustration: FIG. 55.--MEDAL WON BY THE AUTHOR IN THE SAME
COMPETITION.]
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 assistant.
6. For all-round efficiency nothing but a good all-round model, which
can be absolutely relied on to make a dozen (approximately) equivalent
flights, is any good.
7. In an open distance competition, unless you have a model which you
can rely on to make a _minimum_ flight of 200 yards, do not enter
unless you know for certain that none of the "crack" flyers will be
present.
8. Do not neglect the smallest detail likely to lead to success; be
prepared with spare parts, extra rubber, one or two handy tools, wire,
thread, etc. Before a lecture, that prince of experimentalists,
Faraday, was always careful to see that the stoppers of all the
bottles were loose, so that there should be no delay or mishap.
9. If the rating of the model be by "weight" (1 oz., 2 oz., 4 oz.,
etc.) and not area, use a model weighing from 10 oz. to a pound.
10. If there is a greatest height prize, a helicopter model should win
it.[52] (The writer has attained an altitude of between three and four
hundred feet with such.) The altitude was arrived at by observation,
not guesswork.
11. It is most important that your model should be able to "land"
without damage, and, as far as possible, on an even keel; do not omit
some form of "skid" or "shock-absorber" with the idea of saving
weight, more especially if your model be a biplane, or the number of
flights may be restricted to the number "one."
12. Since the best "gliding" angle and "flying" angle are not the
same, being, say, 7° in the former case and 1°-3°, say, in the latter,
an adjustable angle might in some cases be advantageous.
13. Never turn up at a competition with a model only just finished and
practically untested which you have flown only on the morning of the
competition, using old rubber and winding to 500 turns; result, a
flight of 250 yards, say. Arrived on the competition ground you put on
new rubber and wind to 750 turns, and expect a flight of a quarter of
a mile at least; result 70 yards, _measured in a straight line_ from
the starting-point.
14. Directional control is the most difficult problem to overcome with
any degree of success under all adverse conditions, and 15 per cent.,
in the writer's opinion, is far too low a percentage; by directional I
include flying in a straight line; personally I would mark for
all-round efficiency: (A) distance and stability, 50 per cent.; (B)
directional control, 30 per cent.; (C) duration of flight, 20 per
cent. In A the competitor would launch his model _in any direction_;
in B as directed by the judges. No separate flights required for C.
FOOTNOTES:
[48] The better way, undoubtedly, is to allow the competitor to choose
his direction, the starting "circle" only to be fixed.
[49] Or 10 per cent. for duration of flight.
[50] In another competition, held under the rules and regulations of
the Kite and Model Aeroplane Association for the best all-round model,
open to the world, for machines not under 2 sq. ft. of surface, the
tests (50 marks for each) were:--A. Longest flight in a straight line.
B. Circular flight to the right. C. Circular flight to the left. D.
Stability and landing after a flight. E. Excellence in building of the
model.
[51] On the assumption that the model will fly straight.
[52] If permitted to enter; if not see Fig. 53.