1. BEFORE YOU TAKE OFF
Most people will have often sat next to a licensed driver in a car, before they start taking driving lessons themselves. They are already very familiar with the busy world of traffic. The world of gliding is not more complicated, but it is very different. For your own safety and the safety of others, you will first and foremost have to familiarize yourself with the rules of the gliding world. In this chapter we will focus on what you need to know before you make your first flight.
Check all directions – look up as well!
Always walk/stay behind an aircraft ready to launch;
Stay away from winch cables;
- Speak up! If you see something unsafe, say or do something.
CHECK ALL DIRECTIONS
Accustom yourself, when at an airfield, to not only look right and left for traffic, but also upwards. Especially while crossing take-off and landing areas, you need to be 100% sure there is no aircraft on its way to take off or land. Gliders are a type of aircraft without a piston engine or a jet engine, so you will not hear them approach. The long wings of the aircraft make it hard for a pilot to make swift movements to avoid any unexpected traffic crossing the runway. And because there is no engine, the pilot cannot simply “go-around” (abort the landing) and proceed a second landing attempt. Checking all directions will be the most important skill you need to develop. Mobile phones can distract you from carefully checking – only use them with the utmost care.
Gliders that have landed need to be pushed (or pulled back by a vehicle) to the spot from where they can be launched again. Never cross in front of a glider that is ready, or nearly ready for departure. When someone is hooking up the winch cable or tow rope: stay behind the glider. This also applies if you just want to watch a glider launch – do this from behind the aircraft and not diagonally in front of it.
Be very careful around winch cables, the winch driver can accidentally select the wrong cable to be pulled in. A cable can also catch another cable and cause several cables to move at the same time. Never stand in a cable loop and do not touch any of the cables if you are not the person hooking up the gliders.
Gliding is a team sport. You will not be able to fly on your own. Most people learn to fly at a club, or join a club shortly after they have learned to fly. Gliding can only be enjoyed by people from all walks of life if every club member pays their annual fees on time and also performs some jobs at the airfield, in the hanger, at the workshop or in the clubhouse. Of course you mainly become a club member because you want to fly gliders. But you will soon notice that other club members can also teach you new skills to keep the gliding club going. If you participate actively and “see” what needs to be done, instead of waiting to be asked to do something, everything will run smoother, waiting times will be shorter and you will fly more often. And if you work hard to keep everything going, you will receive a lot of sympathy from your fellow aviators as well.
When you start gliding, a whole new world opens up to you. It is important to keep asking all questions you may have to get used to this new world. Stupid questions do not exist. Some things look easier than they are and there may be important things that you will easily overlook without a proper instruction. If you are asked to perform a new task that you haven’t done before, ask someone to show you how to do it. For flight-related questions you have to go to your instructor. For questions concerning the gliding operation you can speak to the duty pilot (the pilot in charge at the launch point) or other experienced pilots.
REPORTING - SPEAK-UP
If you see something that seems unsafe, even if you are not entirely sure, you have to speak up! Most clubs and flight schools nowadays have a flight safety officer who can be reached by phone, e-mail or in person to report unsafe situations to. Doing so should be strongly encouraged. If you have made or witnessed a mistake (and we all make mistakes) we can try to avoid these same mistakes in the future by reporting them and by learning lessons from them. In aviation, the goal is always to have a 'just culture.' This means that incidents and accidents will not be punished unless they were caused by willful violation of the rules or gross negligence.
1.1 INSTRUCTORS AND DUTY PILOT
One of the instructors present at your airfield is usually in charge of the gliding operation that day. He or she is responsible for the general management and the safety. Other duties of the instructor in charge may be to perform a weather and safety briefing before the flying commences. During this briefing often other tasks (for example who is flying the tug plane, driving the winch and who will take on the Duty Pilot role) are assigned to other experienced pilots.
The Duty Pilot is responsible for the smooth running and safety at the launch point and all the movements of gliders and aircraft on the ground. The Duty Pilot reports to the Instructor On Duty directly. The Duty Pilot usually also assigns the students, instructors and other pilots to different school or club gliders. These tasks require a lot of energy and all initiatives to assist (offering help rather than waiting to be asked) the Duty Pilot are usually very much appreciated.
How should I move a glider?
Gliders can be pushed by people or pulled by vehicles like cars or tractors. When we move a glider manually we usually push it backwards.
Place your hands at the thick leading edge of the wing as close to the fuselage as possible. Another person should hold the wings level at one of the wingtips. This person can let the glider turn by reducing or accelerating their walking speed. Close to obstacles there should be someone at each wingtip.
Always avoid touching the canopy, as it is vulnerable and very expensive to repair. Touching the canopy will also make the glass dirty resulting in reduced visibility when flying the glider.
BEHIND A VEHICLE
When transporting a glider behind a vehicle with a short rope, two persons need to escort the glider. One person keeps the wings level at one of the wingtips. He or she is responsible for steering the glider on the ground. The other person walks at the glider’s nose in order to slow the glider down if the vehicle comes to a sudden stop or if the glider starts accelerating on sloping terrain. If a glider does not have a removable rotating transport wheel (called a tail dolly) the person at the nose also needs to push the nose downwards during every turn to prevent the aircraft tail from moving sideways on the ground.
Many clubs and private owners use tools that do not require anybody at the glider’s nose or wing to hold the glider level during transportation. For example: wheels can be placed under a wing to keep them level and the tail dolly can be connected to a car’s towbar using a rod to pull the glider backwards. Be extremely careful when using any of these systems with obstacles and drive at normal walking speed. Always ensure that your canopy is closed and locked before you move the glider.
FASTEN THE ELEVATOR
If you move your glider on an uneven surface; make sure to fasten your flight controls using the seatbelts before transporting the glider. This will avoid abrupt up and down movements of the elevator causing internal damage to the construction.
DO NOT “TURN ON THE WHEEL”
A glider should only be rotated when it is moving forwards or backwards. If we turn the glider when it is not moving we may overload the fixation of the main wheel to the fuselage. If there is no removable tail dolly, someone needs to push the gliders nose down - lifting the tail up - to avoid lateral forces on the tail.
BACK AT THE LAUNCH POINT
The launch point is the place where we position the glider while keeping clear of other gliders and obstacles. Bear in mind that the wings may move up and down when the direction of the wind changes and do not place anything below a glider’s wing. To prevent the wings from dropping and the glider from rotating due to wind direction changes or strong thermals, always remove the tail dolly and place some weight on the wings, for example an old car tire. Alternatively, tie the wing down. If you leave a glider alone never leave the canopy open but keep it closed and locked. Strong winds may blow the canopy open and damage it, in the worst case separating it from the glider.
1.3 TO HOOK ON AND RUN THE WING
- What should I pay attention to when hooking on a glider or running the wing?
TO HOOK ON A GLIDER WHEN WINCH LAUNCHING
Perform this task only after another pilot has taught you how to do it.
A big advantage of hooking on a glider is that you will be close to the cockpit when an instructor is instructing another student before his or her flight. Being near, you might also learn something new from these briefings. When hooking on you work with the winch cable (1), the cable parachute (2), the shock absorber rope (3), the weak link (4) and the release rings (or "TOST rings") (5).
- Do not touch any of the cables when the winch driver is retracting any of the other cables. These cables may be tangled up (or get tangled up while retracting) and a moving cable can soon pick up a second cable. If the winch is equipped with a flashlight, then only touch the cables when the flashlight is off. Attach the parachute to the cable to be used, pull this cable away from the other cables and bring it to the nose of the glider. You also need to check the condition of the cable, all the mounts and the shock absorber rope. There should not be any other cables or parachutes within one wingspan length of the glider. If there are any obstacles; delay the launch and move the glider (or the obstacles) first.
- Check whether the rope is positioned in such a way that it cannot get tangled up. Choose the correct weak link for the glider to be launched.
- The weak link should be blue for most single seat gliders, and brown or black for most two-seater gliders (when winch launching).
- Do not disturb the pilot when they are performing their preflight checks. Wait till they are ready for you to hook the cable on.
- The pilot always needs to visually confirm the color of the weak link before it is being connected to the glider. You can show the weak link by holding it next to the canopy.
- After this, look for the release hook located closest to the center of gravity of the glider, usually below the (rear) pilot’s seat and just in front of the main wheel. Keep the smallest of the two rings between two fingers to be able to connect it to the glider and show an open hand next to the cockpit window (we call this making the call “open”). Move the small ring vertically up into the release mechanism housing. Close your hand to make a fist and say: “close,” to have the pilot release the cable release knob. The cable is now connected.
- Check that the cable is connected properly to the glider by pulling firmly on the absorber rope behind the weak link.
The weak link is a small metal plate, which is designed to break at a certain load. Weak links are color-coded, the color indicates its strength. The weak link is placed in-between the cable parachute and the glider. If we wouldn’t use weak links the forces on the glider could exceed the design limits and the internal construction of the glider might get damaged. This can happen, for example, when you are flying through strong thermals during the launch. If the forces become too large, the weak link will break. We use different weak links for the same type of glider, depending on the launch method. The weak links we use during aerotow launches are usually weaker (they break at a smaller load) than the weak links used during winch launches. If a pilot does not know which weak link they should use, they can find this information in the Aircraft Flight Manual. This is a manual that needs to be kept inside every glider. It is usually stowed behind the (rear-) seat in the stowage compartment.
|Green||3 kN / 650 lbs||aerotow launch method for single seat gliders|
|White||5 kN / 1100 lbs||aerotow launch method for two-seater gliders and winch launch method for some single-seat gliders|
|Blue||6 kN / 1350 lbs||winch launch method for most single seat gliders|
|Red||7,5 kN / 1650 lbs||winch launch method for some single seat gliders|
|Brown||8,5 kN / 1900 lbs||winch launch method for two-seater gliders|
|Black||10 kN / 2250 lbs||winch launch method for two-seater gliders|
1 kN = 1000 Newton ≈ 100 kgf (kilogram force) ≈ 225 lbs
THE WING RUNNER
The person hooking the cable onto the glider is often the same person holding the glider’s wingtip during the initial acceleration of the launch. In a glider you are only able to keep your wings level at a certain speed because you need air flowing along your flight controls to have sufficient flight control authority. Control authority means that you can move the wings up or down or change the direction your glider’s nose is pointing by moving a flight control in the cockpit. The faster you move, the more air will flow along your glider, and the more control authority you will have. For the first seconds of the launch, until the pilot is able to make successful control inputs, the person running the wing needs to keep the wings level. This is also the main reason why every airplane usually departs (or lands) with its nose facing the wind; the headwind will give you some extra airflow towards your wings. As a wing runner, you can keep the windward wing slightly lower if there is crosswind to prevent the wind from getting underneath that wing, which would make it a lot harder for the pilot to keep both wings level.
- Wait until the pilot is ready for launch and the “thumbs up” signal has been given.
- Make sure that the tail dolly has been removed and (for winch launch) that the airbrakes have been locked.
- Check if the area in front of the glider is clear and no person, vehicle or aircraft is about to cross the runway – either on the ground or in the air.
- Check if the area behind the glider is clear. It is close to impossible for the pilot to check if there is any traffic behind him or her since the view to the back is very limited in a glider. You have a very important extra pair of eyes!
- As soon as you are certain a safe launch can be performed, you raise one arm while keeping the wings level with the other arm as a signal for the duty pilot to give the “take up the slack” signal to the winch. This means the winch will slowly retract the cable until the cable is tight. At some airfields signalling the winch driver is done by using light signals, at other airfields phones or radio calls are used. If light signals are used, then you should also call “Lights on!”
- When the rope is tight and the glider starts to move, slowly lower your hand. This is the “all out” signal. The winch will now start to accelerate quickly and you should try to run along as fast as you can before releasing the wingtip without pushing or pulling it.
If there is any abnormality during the “take up the slack phase” of the launch and a safe launch is not guaranteed, as a wingrunner you should shout “STOP, STOP, STOP!” and the pilot has to pull the cable release knob immediately.The duty pilot will give the abort signal to the winch driver.
The abort signal should never be given after the glider is just off the ground in the initial climb. The winch driver will keep the launch going until the glider has reached a safe altitude.
TO HOOK ON BEFORE AN AEROTOW
Most gliders have a second release hook on or close to the glider’s nose for aerotow starts. The wing runner gives the signal “take up the slack” and “all out” to a marshaller standing at an angle in front of the glider and tow plane combination.
Take up the slack: stretching and bending motion with your arms towards your shoulders (A)
All out: point both hands in the take-off direction (B)
Abort take-off: clearly cross your hands above your head (C)
At some airfields they use radio communication between the glider pilot and the towplane instead of a marshaller. Furthermore, hand signals may be different at your club or school. In most cases the towplane is equipped with a mirror and raising the wings may already be the signal to “take up slack”, so always make sure you are aware of the local procedures before hooking on a glider.
Only approach the winch from behind if it is still running and remain in your vehicle or take shelter in the winch cabin. If a winch cable accidentally breaks it may bounce around and act like a chainsaw.
After connecting the cables onto the retrieve vehicle it is important to drive in a straight line from the winch to the launch point. If you don’t drive straight, the cables can get tangled up and it will take a long time untangling them. This would delay several departures.
Most flight club treasurers or flight school owners must know how many gliders have been launched each flying day and how long they stayed in the air. That is why someone is appointed to keep the flight log. The flight log keeps track of who is flying which aircraft as well as the takeoff and landing times. Log keeping is a nice and relaxing task that only requires you to be precise. However, when light signals or telephones are being used to communicate with the winch, the job of log keeper is often coupled with the job of signalling the winch for takeoffs. Only perform the job as a signaler after someone has instructed you properly how to do so.
As a signaler, it is important to not let yourself get distracted and to keep an eye on both the wing runner and the duty pilot. When the wing runner gives you the signal “take up slack” verify that the sky is clear and that there are no aircrafts coming in for landing close to the launch point. Again you are an extra pair of eyes. When you give the “all out” signal, keep an eye on the launch until the glider has reached a safe altitude.
|Light signal||Meaning for the winch driver|
|Light is blinking||Take up (the) slack|
|Light is steady ON until glider is at a safe altitude||Cable is tight; advance power to launch setting|
|Lights OFF before launch power setting||Stop immediately and await further signals|
You will be amazed how much there is to know about the weather. After a few seasons of glider flying your friends and family will come to you for the latest weather forecast. Weather minima that determine whether or not you can fly are different in every country and for each airspace category.
The weather minima (another way of saying: weather conditions) are based on four factors: cloud base, horizontal visibility, wind speed and precipitation. What you need to know about wind speed is that cross– and tailwind are more limiting for gliding than headwind, which is pointing opposite to the direction of takeoff. Some headwind has a positive effect on the launch. The negative effects of tailwind and crosswind will be discussed later on in this book.
|Cloud base (minimum)||1000 ft (+/- 300 m)||1500 ft (+/- 450 m)|
|Horizontal visibility (minimum)||3 km (+/- 2 miles)||5km (+/- 3 miles)|
|Wind speed (maximum headwind)||25 knots ( +/- 12 m/s)||20 knots (10 m/s)|
On rainy days it is often not possible to fly. A single rain shower will not directly lead to all flights that day being cancelled, but when thunderstorms arrive the operation should be suspended. Thunderstorms pose a serious risk to glider flying. Not only is there the danger of lightning, thunderstorms may also cause strong winds that quickly shift in direction, accompanied by rain, ice, hail and snow. Rain has a negative effect on the performance of the glider and it will also decrease the horizontal visibility. Most modern gliders are perfectly capable of getting wet every now and then, but make sure you clear the wings of water droplets before you take off after a rain shower.
Mobile devices and the internet are great sources for retrieving aviation forecasts. Nowadays you can even have live satellite images and weather warnings on your onboard flight computers. Weather forecasts are getting more and more precise; technology is really helping pilots to get better forecasts and weather warnings. All around the world you can have a pretty reliable forecast for the next 48 hours. Cross-country experts use various websites to calculate the amount of distance they can travel on a good day. Some websites are free of charge, other websites require a subscription.
Commercial and military airports employ weather specialists (or have computers perform the same tasks) and they can provide you with weather observations and predictions. They produce METAR’s and TAF’s, which stands for METeorological Aerodrome Report and Terminal Aerodrome Forecast. METAR’s and TAF’s are observations and forecasts for the specific airport that produces them. These observations and forecasts can be very useful to you if you happen to be flying at those airports or if your airfield is located close to them. They are written in a kind of aviation code language and it takes some study and exercise to understand them. Before you obtain your license, your instructors should teach you how to decode them. We will skip most of it for now and only explain the most important elements in this code language.
Wind direction is given in degrees on a 360° scale - rounded off to the nearest ten degrees: North is 000°, East is 090°, South is 180° and West is 270°- and windspeed is given in knots. For example the code 230/15 means that the wind is coming from the direction 230° which is Southwest and the average wind speed is 15 knots.
1 kts ≈ 0,5 m/s ≈ 1,8 km/h
Wind speeds of over 17-20 kts are considered strong winds and wind speeds of over 60 kts and greater are associated with hurricanes and cyclones. Sometimes there is a sudden short increase in windspeed, caused by a thermal or a shift in air pressure, we call this a wind gust. Gusts are indicated by the letter G and added on top of the wind speed; for example 230/15G25, indicates a gust of 10 kts above the average wind speed.
Cloud base is a confusing term. If you get up early in the morning and there is mist or fog with very limited visibility, the cloud base is zero. When the sun starts to heat up the earth this fog may disappear and later on form clouds. Sometimes there are several layers of clouds on top of each other. In aviation we separate these clouds in three categories: low clouds, medium level clouds and high clouds. Thunderstorm clouds (also called cumulonimbus clouds) are the exception because they can occur at every level, from low to very high altitudes.
A layer of clouds is considered a cloud base when more than half the sky is covered with them.
Below we will give you a little bit of aviation code language to help you understand cloud bases:
CAVOK = clouds and visibility okay, meaning no clouds below 5000 ft (+/- 1500 m) above the ground, no cumulonimbus clouds, a visibility of 10 km (6 miles) or greater and no significant weather change to be expected
|FEW =||few =||1/8 - 2/8 =||hardly any clouds|
|SCT =||scattered =||3/8 – 4/8 =||half of the sky is covered with clouds|
|BKN =||broken =||5/8 – 6/8 =||more than half of the sky is covered with clouds|
|OVC =||overcast =||7/8 – 8/8 =||very cloudy|
When less than half the sky is covered with a certain layer of clouds, this is not considered a cloud base. In aviation terms a layer of clouds is indicated with one of the four codes from the table followed by three numbers indicating an altitude in feet divided by 100; for example: BKN003 means broken clouds (covering 5-6/8 of the sky) at an altitude above ground of 300 feet (≈ 100 m).
If there are high rising clouds or thunderstorms are present, codes may be added; for example:
CB = Cumulonimbus (thunderstorm clouds)
TCU = Towering cumulus (clouds that may develop into a thunderstorm cloud)
SCT030TCU means scattered clouds (covering 3-4/8 of the sky) starting at 3000 feet above the ground (≈1000 m) with towering cumulus that may develop into thunderstorms later on.
There are numerous forms of water coming from clouds and in aviation we like to divide them in different types of precipitation. In METAR’s and TAF’s you will find the following codes:
|Rain||GR =||Hail bigger than 5mm|
|RASH =||Moderate Rain Showers||GS =||Hail smaller than 5mm|
|-RASH =||Light Rain Showers||PL =||Ice pellets (frozen rain)|
|+RASH =||Heavy Rain Showers||SG =||Snow grains (light snow)|
|VCSH =||Showers in the vicinity of the airport||SN =||Snow|
|DZ =||Drizzle||TS =||Thunderstorm|
Visibility is measured horizontally and is indicated in kilometers, meters or statute miles.
In METAR’s and TAF’s you can find the following codes:
|BR =||Mist = Visibility is more than 1000 m||FU =||Fumes|
|FG =||Fog = Visibility is less than 1000 m||SA =||Sand|
|HZ =||Haze||DU =||Dust|
|MI =||Minor / Shallow = a very small layer of moisture||VA =||Volcanic Ash|
1.7 MEDICATION, ALCOHOL AND DRUGS
- The “I’m Safe” check
If a prescription drug influences your ability to drive, it will definitely influence your ability to fly. Always read the package leaflet for side effects and ask your doctor whether you are allowed to fly while using this type of medication. The use of soft drugs and hard drugs is never allowed if you are flying gliders; even several days after using them you can still experience negative and unexpected side effects.
As at many other social clubs, glider pilots like to unwind after a day of flying by having a few drinks at the clubhouse. Please keep in mind that alcohol influences your sleep and that you should not drink more than two glasses if you are planning to fly the next day. Hangover effects can last for 48 hours and flying while under the influence of alcohol is very dangerous for yourself and others. Though the legal alcohol limit will differ between countries, you should refrain from having any alcoholic drinks in the period between 12 to 8 hours before flying.
Before every flight perform your “I’m Safe” checklist:
The I’M SAFE checklist
|I||Illness||Do not fly if you have a cold or feel generally unwell.|
|M||Medicine||Do not fly if you are using medicine that may influence your flying and do not fly within 48 hours after anaesthesia at the dentist's.|
|S||Stress||Listen to your body. Do not fly if you are stressed and not able to fully focus on the task ahead. Emotional events or arguments can cause a lot of stress.|
|A||Alcohol||Do not fly when under the influence of alcohol.|
|F||Fatigue||Do not fly if you are tired. Sleep first and come back later.|
|E||Eating||Do not fly if you are hungry or thirsty. Insufficient food intake can lead to serious incidents. Always take plenty of drinking water and food on longer flights.|
SUNGLASSES, WATER, SUNSCREEN
It’s important to look after yourself during a day of flying. Summer days can be long and warm. When you are exposed to the sun you easily become dehydrated. The effects of dehydration can be very serious and lead to concentration loss and headaches. That is why you need to drink water, a lot of water!
Gliders are white, clouds are white and so are snowy mountaintops. White surfaces reflect a lot of sunlight and this can lead to temporary blindness while flying. Therefore you will need to get yourself a pair of good quality sunglasses with a UV (ultraviolet light) protective layer. We do not recommend buying Polaroid sunglasses as these make it hard to read the digital displays in your glider. A glider canopy does not protect you from exposure to UV radiation and this is why you will need to use sun cream as well as a hat. Avoid baseball caps because they limit your visibility. Glider pilots are widely known for their weird sunhats.
On a hot and sunny day, it’s best to delay closing and locking your canopy until just before you are being hooked onto the cable. In hot weather, temperatures rise quickly in the small cockpit of a glider.
Always carry the following personal documents while flying a glider: license (if you have one), medical certificate (obligatory when performing solo flights), proof of insurance and your -up to date- pilots logbook.
The front end of the fuselage is called “the nose” of the glider. The rear part of the fuselage is called “the tail”. Most training gliders have a release hook located in the nose to connect the rope for aerotow launches. If you pull the yellow release knob in the cockpit, the release mechanism will open. Just in front of the main wheel you will find another release hook. This hook is positioned close to the gliders centre of gravity and is sometimes referred to as CG-hook. This hook is used for winch launches and for automobile or bungee launching. The last two launch methods are so rare that we will not discuss them here. Pulling the yellow release knob in the cockpit opens both release hooks at the same time.
The canopy of a glider is very expensive. Dirty canopies need to be cleaned with a lot of water and a designated deerskin or cleaning cloth. Using a dry or dirty towel may cause scratches on the glass. So treat the canopy like you would treat an expensive pair of sunglasses. On the side of the canopy there is a small sliding window. The canopy is most vulnerable at the edges of this window. So open the canopy first if you want to pull the release knop while standing outside the cockpit. Never lift the canopy at the edge of the sliding window but grasp a metal handle or the stronger bottom edge of the canopy instead.
Two-seater gliders used for training usually have a nose wheel, a main wheel and a tail wheel (or tailskid). When you get in the cockpit and sit in the front seat, the glider will rotate on its nose wheel, lifting the tail. During a landing the main wheel and the tail wheel will touch the ground at the same time. After landing the glider will slowly tilt forwards onto its nose wheel
The wingspan of a modern two-seater glider is over 18 meters / 60 feet. Inside the wings there is a very strong construction of spars and ribs; the wings are able to carry over 6 times the weight of the glider at maximum take-off weight. The wing spar runs from the wingtip into the fuselage where it is connected to the spar of the opposite wing as well as to the fuselage. The leading edge of a wing is quite thick and strong; the trailing edge is much thinner. If you look at the cross-section of a wing, you see that the top is rounder than the bottom.
The glider’s tail consists of a vertical and a horizontal part. The horizontal part is called the “tailplane” or “horizontal stabilizer.” The front of the tailplane is fixed to the fuselage, the rear part can be moved and is called the elevator. By pushing the control stick in the cockpit forward the elevator will move down, thereby lifting the tail upwards and as a result moving the nose downwards. This will result in an increase in airspeed. By pulling the stick rearwards, the nose moves up and the airspeed decreases.
It is important to note that the elevator is used to control the airspeed, not (directly) the altitude. A glider trades energy: altitude for airspeed and airspeed for altitude. Reducing airspeed results in an increase in altitude and visa versa. The same principle applies to engine-powered aircrafts, the difference being that chemical energy (fuel) is added that can be exchanged for airspeed.
The vertical part of the tail is called the “fin” or “vertical stabilizer.” The front is fixed and the movable rear part is called the rudder. The rudder is connected to the rudder pedals in the cockpit and used for making turns. You can make “coordinated” turns by using the rudder and ailerons together. Don’t worry too much about it now, you will learn more about it in Lesson 8.
By moving the control stick to one side you will notice the aileron on that side going up and the aileron on the opposite wing going down. The result of doing this in flight is one wing moving down and the other wing moving upwards. This creates a rolling motion in the direction the control stick is being moved.
The airbrakes are used for landing the glider. By pulling the airbrakes lever the airbrakes open on both wings simultaneously, the result is a significant increase in drag. This is needed to make steep descends and to help you land the glider at a specific landing spot.
1.10 INSIDE THE COCKPIT
|1 Sliding window||8 Yaw string||15 Compass|
|2 Canopy locking lever||9 FLARM||16 Radio|
|3 Airbrakes lever (blue)||10 Air vent lever||17 Transponder|
|4 Trim lever (green)||11 Rudder adjustment lever||18 Release lever (yellow)|
|5 Control stick (with push-to-talk button)||12 Air speed indicator||19 Rudder|
|6 Canopy jettison lever (red)||13 Altimeter||20 Electronics master switch|
|7 Radio microphone||14 Vertical speed indicator||21 Side pocket for documents|
- A brief explanation of the basic flight instruments.
The airspeed indicator (12) tells you the indicated airspeed in knots. Airspeed is different from groundspeed, the speed that the indicator in a car is showing. When we are flying into the wind and the airspeed indicator is showing 42 kts, this 42 kts is the speed the glider has compared to the surrounding air.
The groundspeed would be lower in this case. When you are flying with tailwind, the groundspeed is the sum of the indicated airspeed and the speed of the wind. The airspeed indicator in the illustration shows a coloured speed-tape along the numbers. The colours are green, yellow and red:
- Green band – normal speed range, full fight control inputs are possible;
- Yellow band – high speed range, only small control inputs are possible, avoid flying in the yellow speed range in very turbulent weather;
- Red marking – maximum speed, never exceed this speed! (Close to the red marking control inputs larger than 1/3 of the maximum input may damage the glider);
- Yellow triangle – Minimum landing speed in calm air at maximum landing weight.
The altimeter (13) is a barometer. The higher you get, the lower the pressure of the surrounding air. The altimeter shows altitude in feet or meters. The button in the left bottom corner is typically used to set the airfield elevation before take-off. The illustration shows an altimeter indicating 2040 ft.
Vertical speed indicators in meters per second
Vertical speed indicators in feet per minute
The vertical speed indicators (14) (or "variometers") show the amount of climb or sink you are experiencing (either in feet per minute / knots / meters per second ) by responding to changes in air pressure. A needle pointing up means that you are climbing. The vertical speed indicator on the left is a mechanical type (not using any electronics) equipped with a McCready ring. (Lesson 26) The indicator on the right is an electronic vertical speed indicator that also produces an acoustic signal to indicate climb or sink. Both are indicating a climb of 220 fpm.
The compass (15) shows the direction your gliders nose is pointing at -called the “heading”- in relation to the magnetic north pole. This is only a basic instrument and modern flight computers using GPS do a much better job at telling you where you are going.
- 360° or 000° is North
- 090° or E is West
- 180° or S is South
- 270° or W is West
This compass is showing 284°.
The radio (16) is used for communication with other aircraft or persons on the ground. This radio is tuned to the frequency 123,355MHz. The number below is another preselected frequency that can be altered or made active by rotating the selector knob and pressing the button with the arrows. On top of the control stick (5) there is a push-to-talk button to activate the microphone (7) and broadcast your voice over the radio.
The yaw string (8) shows what the direction of the glider is compared to the airflow. When the yaw string is pointing straight at you the resistance is minimal and you lose as little height as possible. When your nose is to the left the yaw string blows to the left. The airflow to the side of the fuselage is causing additional resistance and the glider loses height faster.
The transponder (17) transmits a four number code together with your altitude and some unique identification information. Upon receiving this information; air traffic controllers or computers in other airplanes like airliners or military aircraft can determine your position and avoid collisions. Always check that you are using the correct settings, these may be different at other airfields or countries.
The FLARM (9) is an anti-collision warning device that most gliders are equipped with. It should always stay on. The FLARM transmits your position towards FLARM devices in other aircrafts and it also receives the signals from other FLARM devices nearby. On the display it shows you the relative position of the other gliders compared to yours. When there is a risk of a collision the lights will flash and you will hear an acoustic warning. Do not get distracted by these beeping sounds and flashing lights and keep looking outside the cockpit for traffic. The FLARM system does not substitute normal lookout procedures!
The other parts of the cockpit will be discussed later on (during Lesson 3). The instruments shown on these pages are available in different layouts made by different manufacturers, but they will indicate the same information. We are not discussing any modern flight computers since they are not considered primary flight instruments and you will not need them during your basic training. Also not shown is the landing gear lever that is used for main wheel or “undercarriage” retraction and extension. Many two-seater training gliders do not have a retractable landing gear and the systems may be very different, for instance in some modern gliders the gear is retracted by an electric motor and only requires the toggle of a single switch on your instrument panel.