All about gliding for beginners
Come and experience the thrill of silent flight
How thermals work
How wave lift works
How ridge lift works
NOK's Glider photo album
Gliding is the art of staying aloft in an unpowered aircraft, using invisible rising air currents to gain height and soar away in silent flight. Gliding at its best is a solitary sport, with the pilot pitting his skill against the vagaries of the weather. Success means that you can fly long distances and experience the freedom of the skies.
What Causes This Rising Air
There are three main sources of rising air or lift as we call it: thermals, ridge lift, and wave. Of course, whenever you have air rising in one place, there must be air falling somewhere else; we call this sink. The art of soaring is to find the lift and avoid the sink. It's not always easy.
Thermals are columns of warm rising air, and are triggered by areas of ground that are warmer than their neighbours. For example, a brown ploughed field often warms up in the sun more quickly than the grass field next to it. Thermals are often marked at the top by Cumulus (or "cotton wool") clouds. They can occur anywhere, and are the commonest source of lift. Because the thermals are columns of rising air, gliders need to circle to stay in them.
Ridge Lift is caused by wind blowing towards a steep ridge. The wind blows up the face of the hill, and is still rising some distance above the top of the ridge. Gliders flying in ridge lift tack to and fro along the ridge to stay in the lift.
Wave occurs higher in the atmosphere, and is caused by the wind blowing over high hills or mountains. There is a series of standing waves downwind of the mountains, like the ripples behind a rock in a stream. Wave is marked by bands of lenticular, or lens-shaped, cloud. Gliders flying in wave fly along one side of the wave clouds like surfers, and can travel long distances in a straight line. They can also fly very, very high in wave.
How Does a Glider Take Off
Gliders are usually launched by a winch or towed behind a light aircraft.
A winch is powered by a large engine, and pulls a cable which is as long as the airfield. The launch height is typically between 800' and 2000'.
An aerotow uses a light aircraft to tow the glider into the air, and the launch is usually to 2000', although it can of course be to any height if the pilot is prepared to pay the extra fees. An aerotow can take you to a known source of lift, or to any height, and so is an easier way to start the flight. All launching at Nok Flying Club is by Piper Super Cub light aircraft.
How Long, How High, How Far
A glider can stay airborne for as long as the weather is working in its favour. One of the gliding certificates, which most experienced pilots have achieved, requires a five-hour duration flight. Long-distance cross-country flights can easily take five, six, or even eight hours. When you're learning, though, even twenty minutes is a long time, and can be quite difficult to achieve.
Thermals in Thailand reach cloudbase at typically 4000' to 8000' on a reasonably good day, although 6000' is not uncommon and 12000' is not unknown. Our 2 seat tandem Blanik L13 all metal training glider has a glide ratio of 1:30. This means that from a height of 1km the aircraft (in still air) can cover a distance of 30km.
Pilots who fly cross-country usually fly a triangular course, visiting two pre-declared turning points and then returning home. This course may be 100km for a beginner, or up to 300km or even 500km for an expert. The world distance record is over 3000km, in the Andes , and took over 15 hours.
On March 3rd 1999, Jim and Tom Payne, flying an ASH-25 in California , broke the world record for a 300K out-and-return: 1 hour 7 minutes, 269Kph! That was in the morning. In the afternoon, they did a 500K out-and-return in 2:02, 247Kph. Apparently, the wave lift was quite good. Most pilots, it has to be said, are quite content with much less than this.
Who Can Be a Glider Pilot
Almost anybody. You can't fly solo until your sixteenth birthday, so we normally don't start to teach youngsters much before this. If you are particularly large or small , we may not have a glider that fits you. Between these limits, almost anyone can fly. We have members who started to learn after they retired at 65, and members who went solo on their 16th birthday.
The level of ability required is similar to that needed to drive a car, so almost anyone can do it. There are very few people who seriously try to learn to fly, but who fail to reach solo standard.
In particular, there is no advantage in being male, and many instructors think that women often make better pilots.
How Do I Learn to Glide
If you want to learn to glide, the only way to do it is to join a club and fly regularly. If you want to find out if you want to learn to glide in Thailand , there is (at the moment) only one way to go about it. Just contact Nok Flying Club 06-6702449 and ask for a Trial Lesson . You'll get a briefing and a trial flight, and 28 days membership of the Club. If you explain that you're thinking of taking up the sport, you'll get a lot more information about flying in general, and the Club in particular, than the visitor who's just come along for a bit of fun.
If you want to try more than just a flight, we run one-day courses , or you can arrange to visit us for a week. This is plenty of time to learn to fly, although there are airmanship and judgement considerations that will probably mean that you won't fly solo. However, if five days isn't enough to find out whether gliding is for you, then it probably isn't.
Is Solo The End Of It?
No, solo is just the beginning. Once you've gone solo, you'll undergo a period of supervised solo flying, and then you'll start working towards your Bronze 'C' Certificate.
The Bronze includes written exams and tests of your flying, airmanship, and cross-country ability. When you've reached Bronze standard, you are free to fly solo cross-country, which is the aim of most pilots. At this stage, most people are thinking about buying a share of their own aircraft.
It's possession of the Bronze that marks you as a Real Pilot. The Silver 'C' Certificate is a certificate of cross-country achievement. There are three legs: a 1000m climb, a 5-hour duration flight, and a 50km cross-country flight away from home. The Silver is within the ability of almost all pilots flying almost any aircraft.
After the Silver are Gold and Diamond, which require 300km/500km flights and 2000m/3000m climbs. These require the necessary conditions, high-performance aircraft, and high-performance pilots, so they are not an automatic progression.
Alternatively, but not mutually exclusively, are the dual flying ratings: P1, Passenger Carrying; BI, Basic Instructor; Assistant Category Instructor; Full Category Instructor. The instructors that you fly with were once novice pilots like yourself.
What Are the Rewards
The rewards are what you make them. Some pilots are happy soaring locally, always staying in range of home. Others push themselves to the limits of their ability by flying longer and longer cross-country tasks. Others take to instructing, either introducing visitors to the sport that we're all hooked on, or training new pilots from being a complete novice, through to solo standard, and on to being a cross-country pilot.
Whatever targets you set yourself, you are always facing the challenge of the weather, and the sense of achievement when everything goes right is enormous.
What's more, it's unlikely to be anything like what you do by way of employment, so it's a very good way to relax at the end of a stressful week at a desk or looking after a family.
Because we're a Members' Club, we all have to work together as a team on flying days, so there's a lot more to the day than just flying. As a result of this teamwork, there's a strong social side to the Club, and most people wind down after a busy day over a drink together in the clubhouse
Surely It Is Expensive?
No, not at all. In fact, the overall Cost of Flying compares very favourably with many other hobbies. At Nok Flying Club in particular, the costs are very modest, because we're a Member's Club, and nobody is making a profit out of the flying.
The annual subscription is well below what you would pay for membership for many other similar hobbies, such as a Golf Club or a Marina . While you're learning to fly, your flying fees will typically be £15 to £20 a day, although long flights are more expensive (and very much more enjoyable), which is many times cheaper than learning to fly a light aircraft.
We run a Junior Sponsorship scheme which gives financial help to youngsters, to the tune of approximately half the cost of going solo. Most solo pilots want to own their own aircraft, rather than having to queue up to fly the Club's aircraft. The most common way to do this is to form, or to join, a syndicate of three or four people who share a glider. There are many second-hand gliders available, of various ages, and a first solo aircraft such as a K6 might cost about 350,000baht, shared between four people. Once you have your own aircraft, you pay launch fees but not flying time fees, although instead you can expect to pay 30,000baht a year for insurance, maintenance, and certification.
If you try to keep up with technology, though, that's when it starts to get expensive. All new gliders are built of high-tech materials and have high-tech cockpits, and for those, you can spend all the money you have and more besides: 2.8m baht, 4.2m baht, even 5.8m baht, and that's without the cockpit computers and satellite navigation systems. The most expensive glider is the Stemme, a high-performance high-tech two-seater motor glider, a snip at 9.2m baht.
Flying Gliders in Thailand here...
Glider pilot's course here...
Trial flight here...
Gliding links here...
Thai Air Law here...
Aerotow procedure here...
Tow pilot rating here...
Tow pilot notes here...
Flying the Blanik here...
Ground crew here...
Questions & answers here...
NOK news here