WHAT
IS A GLIDER, OR SAILPLANE? |
A
glider is a high performance motorless aircraft which is designed to have a very flat
glide angle. This is expressed as a ratio - for example modern gliders are being made with
a glide ratio of up to 55:1. In other words in still air it can fly 55 feet forward and
only lose one foot in altitude. By contrast, an average light plane has a glide ratio of
about 10:1 with the engine off. The average glider flying today has a glide ratio of about
40:1 to 50:1. |
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HOW
MUCH CONTROL DO YOU HAVE OVER A GLIDER? |
The
glider has conventional directional controls just like any other aeroplane, and the pilot
has complete control over where the glider is going. The motive power however is provided
by gravity, just like a car coasting down hill. In the glider, the pilot has control over
the steepness of the "hill", and can point the nose down to got faster, or up to
go slower. If the nose is raised too much, the speed will reduce to the point where there
is not enough airflow over the wings to generate lift, and the glider will
"stall". If this is not corrected by promptly lowering the nose, a spin could
develop. This is also easily corrected, but of course a well trained pilot does not allow
such things to happen! To keep flying, the nose is always pointing slightly down. |
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HOW
DOES THE GLIDER STAY UP WITHOUT AN ENGINE? |
Initially,
the glider is towed up to about 2000 ft by a power plane, called a "tug". The
tow rope is about 120-200 ft long. When the desired height is reached the glider pilot
pulls a knob, and the rope is disconnected from the nose of the glider. The tug now
returns to ground and the glider is on its own. Now the really skilled part begins. The
glider pilot must now start to search for a thermal. This is a rising column of air, which
has been warmed by contact with the ground, heated by the sun. An instrument known as a
variometer helps to shown the pilot when he is in a thermal, and he now circles within it
so as to gain altitude. Remember that the nose of the glider is always pointing slightly
down, and that it always descending within the mass of air that surrounds it. However, if
that mass of air is going up away from the ground at a faster rate than the glider is
going down within it, the end result will be that the glider gains altitude relative to
the earth below. This gain of altitude can be as much as 1000 ft per min. more, depending
on conditions. It's great fun and challenging! |
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ARE
GLIDERS VERY STRONG? |
Gliders
are built to very stringent standards and are also maintained to the highest standards
specified by the Department of Aviation. Structural failure is virtually non-existent in a
properly maintained glider. In fact, gliders can perform manoeuvres that are totally
forbidden in the average powered plane, for fear that the plane would be over-stressed. |
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HOW
FAST CAN A GLIDER GO? |
Some
modern gliders have a top speed of up to about 240 kph. A normal thermalling speed is
about 70-90 kph. |
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HOW
HIGH CAN YOU GO IN A GLIDER? |
Thermals can go as high as 14,000 ft or more. Above
10,000 ft it is compulsory to use oxygen. In certain conditions, known as "wave"
flying, heights of 30,000 ft are common. The world height record is 14,102 metres (46,000
ft). |
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HOW
FAR CAN A GLIDER FLY? |
In
the summer, flights of 300 kms are commonplace. Keen pilots frequently make flights of
500-700 kms. The world record for a flight in a straight line is 1,460 kms (908 miles). |
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HOW LONG CAN A GLIDER STAY UP? |
| On a really good day during summer, flights of
around 8 hours are possible, provided you have the skill and patience. |
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| WHAT WOULD HAPPEN IF YOU LET GO OF THE CONTROLS? |
| Nothing much at all! The glider will just sail on
beautifully by itself mainly, although it will gradually wander off course, and will need
a finger tip correction. A glider is an extremely stable aircraft, and you have to be
doing something woefully wrong to make it misbehave. |
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| HOW SAFE IS GLIDING - IS IT A DANGEROUS SPORT? |
| Most pilots will tell you that they feel safer
"up there" than driving on our roads. There is the occasional mishap, but
statistically, gliding has been shown to be about as safe as normal airline flying. If,
due to pilot error, a potentially dangerous landing takes place, the risks are not as
great as in a similar situation with a powered aircraft, because there is no heavy engine
to plough into the ground, no fuel to ignite, and the landing speed is relatively slow.
Also in a ticklish situation the pilot work load is far less, due to the lack of engine
systems etc. A glider can quite easily be landed in a smallish farming paddock, and all
pilots routinely practise such landings as part of their continuing training. Of course
there is no room for the idiot or the "smart Alec". The pilot is expected to be
a responsibly minded person. |
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| IS GLIDING SCARY? |
| Not really! Even people who have a funny feeling
when looking down from a tall building, do not have the same feeling in a glider or light
power plane. Of course, gliding can be a hair-raising experience if you are stupid enough.
So also can motoring! Normally gliding is a delightfully serene experience, as any pilot
will tell. |
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| HOW CAN A GLIDER TRAVEL LONG DISTANCES WITHOUT AN
ENGINE? |
| The glider gains altitude by using a thermal, then
sets off in the desired direction. In doing so it will slowly lose altitude. Before too
much height is lost, the pilot will seek another thermal, gain height in it, then set off
on course yet again. So it is by a combination of thermalling and straight flight that
long distances can be covered. |
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WHAT HAPPENS
IF THERE ARE NO MORE THERMALS TO BE FOUND? |
| Yes, this can happen, but then the pilot goes
through a simple well rehearsed routine, and lands in a suitable paddock. Due to the slow
rate of descent, the glider has plenty of time to find a paddock and plan a safe landing.
The glider can then be re-launched by a tug, or can be retrieved by a car and glider
trailer. Most gliders are fitted with two-way radios, and this allows the pilot to keep in
touch with his base. Special radio frequencies are reserved for gliders. |
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| HOW OLD MUST ONE BE? |
| The lower age limit to go solo is fifteen, and
there is no upper limit, as long as you are in good health. There are hundreds of pilots
well into their sixties, and some well over seventy. |
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| HOW MUCH WILL IT COST TO LEARN? |
| This will depend upon how long you take. The
quickest way is to enrol in a five or seven day course. Many people will solo within a seven day course. In such a case, an average cost to reach solo
stage is about $1200. If you cannot spare time to take a concentrated course, you may
learn over a longer period as spare time becomes available. This will probably mean that
the cost will be somewhat higher, as you will take more hours overall. After reaching solo
stage, there are many more goals attainable to keep you interested and challenged. |
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| HOW CAN I GET STARTED? |
| The first thing to do is to contact the Caboolture Gliding Club. We will be pleased to
arrange a trial flight for a small
fee. If you think you will like it, you can then join up and get started in earnest. |
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