Glossary
On this page you will find a list of gliding terms that you might hear on and off the airfield. It is easy for some of the older members, or Cranwell Gliding Club members, to forget that the vast majority of people don't have a clue about the sport when they come flying for the first time. Hopefully this will serve as a useful reference if you hear something mentioned, and don't have a clue what it means!
- A Badge
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The first badge in the British Gliding Association badge system, which is gained after the pilot has flown solo for a flight of 30 seconds or more, and demonstrated a knowledge of basic air law.
- Ab Initio
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Literally means 'from the beginning', used to refer to a new person to gliding, who requires instruction from the beginning.
- Aeronautical Chart
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A map of an area a pilot intends to fly over, with navigational features, airspace and other relevant information marked on it.
- Aerotow
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A common type of glider launch where the glider is attached to a powered plane by a rope, and towed into the air. Launching this way, gliders can choose the height of their launch, and where they release, allowing the tug pilot to tow them into an area of lift.
- Altimeter
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An instrument which tells the pilot their height above the airfield they launched from. It is essentially a barometer, and measures pressure, so is affected by local pressure changes.
- As. Cat.
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Common name for an Assistant Category rated Instructor. This type of instructor can teach all aspects of flight, and can send people solo under the supervision of a Full Category rated Instructor.
- ASI (Air Speed Indicator)
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An instrument which tells the pilot their air speed. It is often marked with coloured arcs which tell the pilot different ranges of speeds the glider can fly at.
- Auto Launch
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A type of glider launch that is a cross between an Aerotow and a Winch Launch. The glider is towed behind a car until it has enough speed to fly and gain height. This type of launch is rarely used now.
- B badge
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A British Gliding Association badge, which can be claimed after a flight of 5 minutes or more above a certain height. Not many people claim this badge any more - it is a hangover from the old days of gliding when a 5 minute flight was more of a major achievement.
- BGA (British Gliding Assocation)
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The governing body for gliding in the UK. It handles instruction, maintenance, operations and competitions in gliding.
- BI (Basic Instructor)
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A Basic Instructor can teach upper air work only - speed control and coordination of controls. They cannot teach launches or landings and must be in control for those parts of the flight.
- Bronze Badge
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This badge comes after the 'B' Badge in the British Gliding Association badge system. It requires a ground exam, 2 flights of 30 minutes or more, a flying test, a field landing exercise and a minimum number of solo flights to claim it. It is often done in conjunction with the Cross Country Endorsement, which will allow holders to fly cross country.
- Bungee Launch
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A type of launch that uses an elasticated rope to launch the glider down a hill. It is used on ridges on days when the wind is causing the ridge to generate lift, which enables the glider to regain height after the launch. Several people take the other end of the rope and run down the hill with it to provide tension. Currently only a few clubs still use this launching method in the right conditions.
- Cable Retrieve
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When winch launching, these are the vehicles which will tow the cables back to the launch point ready for the next glider.
- CFI (Chief Flying Instructor)
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The Chief Flying Instructor is in charge of all flying done at the gliding club, and lays down the club rules. His or her word is law on the airfield. Each gliding club has a CFI.
- Check Flight
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If a pilot has not flown for a while, they will usually be given a check flight with an instructor. It is simply an instructional flight to ensure the pilot is in good practice again before they are let off on their own.
- Circuit
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In preparation for landing, pilots fly a 'circuit' around the airfield, which ensures that all approaching aircraft follow the same pattern. The circuit also sets up the glider or plane for a good approach to the landing area.
- Cross Country
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A cross country is a flight set away from the airfield, out of gliding range. Different waypoints are used along the way to mark the route out and pilots attempt to fly around the whole route, and usually return to the same airfield.
- DI (Daily Inspection)
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Before each glider flies on a particular day, it has a daily inspection. This involves checking the paperwork, fitting the battery and checking the instruments, checking the controls and walking around the glider to make sure there is no damage.
- DI (Duty Instructor)
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The Duty Instructor is in charge of airfield operations on a particular day. They authorise all flying done on that day, and decide who is allowed to fly what gliders based on their experience and the conditions. The duty instructor is always a full category rated instructor, and rotates between different club instructors on a rota.
- Diamond Badge
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The Diamond Badge is the highest FAI gliding badge, and requires a 300km goal flight (a triangle, returning to your home airfield), a 500km free distance task, and a 5km (16,405ft) height gain.
- DP (Duty Pilot)
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The Duty Pilot helps the Duty Instructor on the field by organising people to operate the winch, drive the cable retrieve vehicles, organise students with instructors and make sure money is taken at the end of the day. The Duty Pilot slot is done on a rotating basis by anyone who is solo or above.
- FAI (Fédération Aéronautique Internationale)
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The Fédération Aéronautique Internationale, or World Air Sports Federation, is the international body representing many different air sports, including gliding. The silver badge in gliding and above are FAI badges rather than British Gliding Association ones.
- Field Landing
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If a pilot is on a cross country flight, and is getting low, he will try to find a thermal or some other lift to keep him airborne. If there is no lift around, the pilot will be forced to land in a field - this is called a Field Landing!
- Full Cat.
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A Full Category Rated Instructor can teach all aspects of flight, send people solo, examine people on bronze flying exams, and can be the duty instructor on the field. They can also be a CFI.
- Glass Fibre
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A composite material formed by layering sheets of woven glass strands and bonding them together with a high strength resin. Most gliders in the 1970s and 1980s (such as the Astir) used a glass fibre construction, but most use carbon fibre construction now.
- Glide Ratio / Glide Angle / Lift to Drag Ratio
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The glide ratio of a particular glider describes how far forwards a glider will fly for a given height. A glide ratio of 1:45 (or 1 in 45) means the glider will fly 45ft forwards for every 1ft lost in height. This is also referred to as the Lift to Drag ratio, or L/D. The glide angle is the actual angle the glider will fly at as a result of this ratio.
- Gliding Range
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Something is said to be 'in gliding range' if the glider can reach it from its current height and position. Obviously this varies from glider to glider, and the wind strength of the day.
- Gold Badge
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The gold badge is an FAI gliding badge requiring a 300km free distance flight, a 5 hour flight (which is also required for the Silver badge) and a 3km (9,843ft) height gain.
- GSA / RAFGSA (Gliding & Soaring Association)
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The Royal Air Force Gliding & Soaring Association was set up to allow service men and women who don't normally fly (eg ground technicians, cooks, engineers etc) as well as civilians to fly gliders at RAF subsidised rates. There are currently about 10 RAFGSA gliding clubs around the country, with access to a first class fleet of gliders. It is not supported with public money, but by the RAF Sports Charities board, and aims to promote gliding throughout the RAF.
- Land-out
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When a glider pilot is forced to land half way round a cross country task, either in a field or at another airfield, this is known as 'landing out'.
- Launch Point
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The place on the airfield where all the gliders launch from and land again, and the centre of activity on the field, is known as the launch point. At Cranwell, the launch point is a yellow double decker bus.
- OIC (Officer In Charge)
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The Officer In Charge is a position in RAFGSA gliding clubs who is a servicemen being the point of contact with the RAF and the airfield the club is located at. They are in charge of sorting out all issues and communications between the club and the RAF themselves.
- Performance
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The performance of a glider is dictated by several characteristics - mainly by its glide angle and climb performance in a thermal, across its entire speed range.
- Primary
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There are some very basic gliders which consist of not a lot more than a seat with wings, used to 'hop' across airfields for training in the early days of gliding. These gliders are often referred to as 'Primaries', short for Primary trainer. They are not used for training any more, but many still exist which are flown for fun.
- Silver Badge
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The Silver Badge is the first FAI gliding badge, which is internationally recognised. Requirements for claiming this badge are a 5 hour flight, a 1km (3,281ft) height gain, and a 50km flight, which will often be the first cross country flight a glider pilot flies.
- SLMG (Self Launching Motor Glider)
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A self launching motor glider is a glider with an engine - either fixed, or one that can be folded away after launch. The engine can be turned off which turns the aircraft into a glider, and can be started again mid flight if the pilot gets low on a cross country task, to avoid landing out. A pilot's licence is required to fly one.
- Soar / Soaring
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Soaring describes the art of using the movement of the air in the atmosphere to gain height in an unpowered glider. The main forms of lift are thermals, ridge lift and wave lift. Flights of many hours long can be achieved by soaring on the air currents.
- Solo
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A solo flight is one in which the pilot is on their own - with no instructor or student. On average it takes about 60 flights for a beginner to learn to fly and be sent solo.
- Spin
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A spin is a state in which the aircraft has one wing which is stalled and one which is not, or both wings stalled but by different amounts. This results in the aircraft spinning around due to the different forces being created on each wing, and descending. Glider pilots are taught how to recover from spins before being allowed to fly solo.
- Spiral Dive
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A spiral dive is a state of flight with a nose down attitude that can be confused with a spin. The difference between them is that the glider is not stalled in a spiral dive, and speed & g-force increase as the spiral dive deepens.
- Stall
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A stall describes the situation in which the wings are being asked to do too much work, and stop producing useful lift. A glider will easily recover from a stall by lowering the nose and regaining flying speed.
- Tailplane
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The tailplane is the horizontal part of the glider's tail, on which the elevator is mounted. It produces lift to balance the forces being created by the wings and keep the glider flying straight.
- Thermal
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A thermal is a rising bubble of hot air. It usually forms when the sun heats some parts of the ground more than others, and the ground in turns heats the air around it. Gliders can turn inside these bubbles and gain height.
- Tug
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A tug is the word used to describe a powered plane being used for an aerotow, much in the same way as a tug boat tows other boats.
- Variometer
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An instrument that gives the pilot information on whether the air he or she is flying in is rising or sinking. It works by measuring the change in pressure to detect when the glider is in lift or sink. Most gliders have an electronic variometer as well as a mechanical one, which can provide the information as an audible beep, allowing the pilot to concentrate on other aspects of flying. A higher pitched beep means the glider is rising, and a low pitch sound means it is sinking.
- Weak Link
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Every launch uses a 'weak link' which is a specific strength for the particular glider. The weak link will always break before the launch puts too much strain on the glider (either a winch cable or an aerotow rope), it is there as a safety measure.
- Wheels Up
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Sometimes a pilot flying a retractable wheeled glider will forget to lower the wheel before landing, resulting in a 'wheels up' landing. On grass, this usually just ends up being embarrassing for the pilot, but it can cause damage, especially on a concrete runway!
- Winch
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The winch consists of a large engine, a cab for the driver to sit in, and 1 or more drums with a large length of cable. It is designed to accelerate the glider to flying speed in a matter of seconds, and provide power to it for the remainder of the launch.
- Winch Launch
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A winch launch uses a large winch at the opposite end of the field to the launch point, and a steel cable running between the two. The winch accelerates the glider to flying speed, which can then climb until it is above the winch, where the cable is released. Typically, launch heights are around 1,500ft. Winch launches are a cheap and efficient way of getting gliders airborne.