Glider Flight Tutorial

Just like a conventional aircraft gliders have the typical flight controls:

• Central flight stick to deflect the elevator and aileron
• Foot pedals to control deflect the rudder

Unlike smaller general aviation airplanes gliders have a very long wing and because of this the adverse yaw effect of the ailerons is quite pronounced. A well balanced glider needs full rudder input with full aileron input to roll into or out of a turn coordinated.

Because of the very sleek design gliders do not have a lot of drag and a very shallow descent angle. Air-brakes are needed to control where the glider lands . They create a lot of drag and also spoil some of the lift of the wing and are also very effective dive brakes.

High performance gliders typically have a retractable landing gear which is either operated mechanically or with an electric motor.

Some gliders are also equipped with flaps that change the wing camber. In high speed flight these flaps are deflected slightly up towards negative flap angles to decrease the drag.

Gliders can also have a retractable engine. One of these gliders is the Antares 21E in Aerofly FS, which has an electric motor which drives a propeller that retracts into the fuselage when no longer needed.

The Antares 21E is also capable of launching on its own power but not all gliders with an engine can do this. Some gliders only carry around the engine in case they cannot find any updrafts. Then they can deploy the engine mid flight and gain some altitude to continue the flight or return home. In competitions the use of the engine is monitored and the scoring typically ends as soon as the engine is used during the flight task.

The cheapest instrument in a glider is also one of the most important ones. The yaw string is a small string that is taped to the canopy glass, in view of the pilots. When the fuselage is in a side-slip the yaw string also deflects to the side and indicates to the pilot that the relative airflow is coming from a side direction and no longer straight from the front. This side slip causes additional drag and glider pilots aim to center the yaw indicator string all the time to create as little drag as possible to fly as efficiently as possible.

On the airspeed indicator you can find a yellow triangle which marks the recommended approach speed for maximum landing weight. Depending on gusts, headwind and potential downdrafts in the pattern pilots typically add additional margins on top of that airspeed. The green arc is the normal airspeed range during flight and the yellow arc indicates the airspeed range to avoid in rough air. The red marking shows the maximum airspeed, velocity never exceed (VNE) during flight. Gliders with flaps also have a white arc which shows the airspeed range for positive flap deflections.

Because gliders rely on detecting the vertical movement of the air mass around them they need a good indicator for this. A conventional vertical speed indicator would not be sufficient for this purpose because when the glider pulls up to reduce airspeed the VSI would show this as false positive updraft. That’s why gliders use a total energy compensation (TEK) which incorporates the loss or gain in airspeed. This works quite well in calm air but the indication is disturbed by horizontal gusts and also is somewhat delayed because the air first has to accelerate the glider before an updraft is detected on the instrument. By the time the updraft is detected the glider often has already flown through the core of the thermal and needs to fly back towards the center.

The latest glider variometers use accelerometers and gyros to compare the predicted motion of the glider itself with actual measured movements. From this difference a much faster and less error prone detection is possible.

The Antares 21E features a large wide-screen display with a moving map, airspeed and altitude tapes as well as several useful info-boxes like the height above ground derived from GPS position.

• Rotate the upper left knob to change the volume of the variometer
• Rotate the lower left knob to adjust the map zoom
• Rotate the upper right knob on the device to change the display mode

On the variometer displays (both devices work similar)

• Push the middle button to change the page group (Wpt, Tsk, etc.)
• Push the up/down to switch between pages in a group
• Change the switch on the flight stick to switch between the vario mode and the speed command modes

The vario page displays the speed command as up or down diamonds. When the diamonds point up then you should slow down to take advantage of rising air. If they point down then you should fly faster through the descending air.

In the bottom center of the front panel you can find the combined COM/XPDR/ALT display.

• Press the CHN bezel select to show a dedicated page for the active and standby COM channel. On this page use the rotary knobs to adjust the standby frequency and swap it to active by pressing the small knob in.
• Press the XPDR bezel select to display the transponder code entry. On that page rotate the knobs to adjust the squawk code and press the small knob in to confirm.
• Press the BARO bezel select and then rotate the knobs to adjust the altimeter pressure setting.

The Antares 21E has multiple rechargeable battery cells inside the wings which provide power to the electric motor. The motor and power electronics are controlled by the Electronic Drive Control System (EDCS) which has display inside the cockpit.

• During flight the normal flight page is shown
• Extending the engine pylon by moving the throttle lever forward displays the motor page.

One of key features of the EDCS display is the caution and warning system. The system monitors not only the propeller speed, battery voltage, current, etc. but also the position of the landing gear and airbrake (spoilers).

If the system detects an abnormal condition it issues a caution or warning depending on the severity and displays an amber or red box at the top of the screen with a text message and also plays a voice message to alert the pilot.

• Caution Landing Gear Retracted - You deployed spoilers for landing but have not yet extended the gear
• Caution Spoilers unlocked - You extended the engine but the spoilers are not yet fully retracted

On the EDCS you can see the the remaining battery charge, voltage and current flow as well as the status of the landing gear, engine pylon and other parameters.

On the ground you can press the MODE button on the EDCS to cycle through the preflight pages and electronic checklist.

• Press the MODE button to cycle through the checklists on ground

One of the newer additions to gliders are red flashing high power LED anti-collision lights located in the canopy which flash when there is traffic approaching from the front. These lights make it much easier to spot a glider with its thin silhouette.

• Before takeoff set the Anti-Collision-Light (ACL) switch to on.
• The light may be reflected internally which can be distracting in low light conditions, then you can turn off the light by setting the switch to off (recommended only when you are about to land soon).

The side window of the glider can be opened by pulling the plexiglass handle aft. The canopy can also be opened by pulling both latches aft (click on the latches). As long as both sides are open the canopy also opens up. To close the canopy click the latch again, wait for the canopy to close then latch the other side as well.

• Drag the handle on the side window to open/close it
• Click the canopy latches to open/close it.

To select a winch launch go to the location menu and select a runway longer than 600m or select one of the bespoke winch launch locations on the map.

• Select a glider in the aircraft menu first.
• Find your desired airfield, in our example EDST Hahnweide
• Click on the mint colored glider symbols OR
• Click on the yellow airplane symbol on a runway
• Check that winch launch is selected on the right hand side of the menu
• Return to the main menu and start the flight

In the simulation the winch cable is now already connected to the glider.

• Check air-brakes are retracted
• Check pitch trim is set for winch launch (about 15-25% nose down)
• Press the assigned glider action key or
• Press the button in the menu overlay to start the launch

The copilot can fly the entire winch launch for you

• Engage the copilot using the lower right copilot menu overlay or
• Engage/Disengage the copilot with the default key ‘C’.

If you have never flown the winch launch before we recommend engaging the copilot to see how the launch should normally look like.

There are several phases in a winch launch, which we are now going to break down individually.

Initially the wing holder will hold your wings level but as speed builds up the wing holder won’t be able to keep up very quickly. In cross wind conditions or due to sloped terrain the wings can start to fall down back to the ground which must be avoided at all cost. Because the airspeed is very low at this time full aileron may be necessary. If the wing touches the ground the launch must be aborted immediately to avoid deadly cartwheeling.

• Use aileron and rudder input to maintain wings level and lateral direction with rudder.
• If the wing touches the ground immediately disconnect from the winch using the yellow hook handle, your assigned button or key or the button on the screen overlay.

After lift off the glider will gently start to pitch up on its own.

• Over a period of 3-4 seconds gently increase back pressure on the elevator
• Start to lift the nose up higher and higher
• Maintain wings level

If there is a crosswind the glider will start drifting with the wind and after the glider released the parachute on the cable would also fall sideways by a significant distance which can be dangerous to bystanders close to the winch. To counter the crosswind the glider needs to fly into the wind.

• If there is a crosswind then slowly lower the wing that points into the wind (about 5-10° of bank are usually enough).
• Continue to pitch up gently until you reach about 50-70% of up elevator or until the airspeed starts to decline
• The airspeed should now stabilize between 100-130km/h, depending on the glider and wind conditions.
• If the airspeed is too high you can gently pull up further but be careful not to do this gently to avoid the weak link to break because of the very large forces at play
• The elevator is typically held between 50-80% up throughout this phase.

Towards the end of the launch the glider nose lowers on its own and at the same time the winch also reduces power to ease the cable release.

• Slowly release the elevator input back to neutral so that the pitch attitude reduces back to a normal free flight attitude.

The rope automatically disconnects from the glider when a force pulls rearwards on the winch hook. Glider pilots then actuate the hook release 3x to make sure no remaining parts of the rope or cable remain attached to the glider.

• Click the yellow hook release in the cockpit or
• Press your assigned hook release key or button

• Rope released 3x
• Check the surrounding for other traffic
• Adjust flaps if needed
• Trim the glider to the desired airspeed
• Select gear up
• Reset the accelerometer
• Adjust variometer volume

To select the aerotow go to the location menu and select a runway longer than 400m or select one of the bespoke aerotow launch locations on the map.

• Select a glider in the aircraft menu first.
• Find your desired airfield, in our example EDST Hahnweide
• Click on the yellow glider symbols OR
• Click on the yellow airplane symbol on a runway
• Check that aerotow is selected on the right
• Return to the main menu
• Start the flight

In the simulation the rope is now already connected to the tow aircraft and glider.

• Check air-brakes are retracted
• Check pitch trim is set for aerotow launch (about 30% nose down)
• Press the assigned glider action key or
• Press the button in the menu overlay to start the launch

The copilot can fly the entire tow for you

• Engage the copilot using the lower right copilot menu overlay or
• Engage/Disengage the copilot with the default key ‘C’.

As soon as the rope is tightened the tow aircraft increases throttle to max power.

• Hold aft elevator at first to increase directional stability
• Maintain wings level with ailerons. Full deflections may be needed
• Control the direction with rudder to follow straight behind the tow.

In case your wing contacts the ground immediately disconnect using the yellow hook release in the cockpit, your assigned key/button or the screen overlay button.

When the airspeed has increased to between 45 - 60km/h the glider will soon start to fly.

• Neutralize the elevator so that the glider starts rolling on the main wheel.
• Maintain direction with rudder and wings level with aileron

When airspeed increases above the stall speed the glider starts to lift off on its own. The tow plane usually is still rolling down the runway at this time.

• Add increasing nose down input so that the glider flies very close to the ground, ideally without touching it.
• Stay below 2-3m to avoid pulling the tail of the tow plane up and its nose into the ground.
• Maintain wings level with ailerons and follow the tow laterally with rudder

Staying low but off the ground will decrease the required takeoff distance for the tow aircraft significantly.

The tow eventually also reaches its lift off speed and starts to pitch up.

• Follow the climbing tow aircraft using small elevator corrections
• In case of a crosswind slowly allow the glider to weather-vane towards the leeward side so that the glider sees the tow from straight behind with the two aircraft now drifting across the ground together.

For the remainder of the tow the glider should stay straight behind the tow-plane.

• Adjust elevator to maintain about the same altitude as the tow plane. Ideally the wheels of the tow plane or the center of the tow aircraft are on the horizon but this also depends on the aircraft used and pilot preferences and standard procedures.
• Use pitch trim to reduce constant pressure on the stick
• Use ailerons to maintain the same bank angle as the tow aircraft in front
• Use mostly rudder and only a very small bank angle correction to reduce lateral offsets to zero to see the airplane straight from the rear. Focus on damping the side-to-side movements, not as much on the current offset distance.

When the tow aircraft starts to fly a turn

• Keep the tow aircraft in front of the horizon vertically
• Follow the tow’s bank angle into the turn

During the turn the glider should be positioned on the imaginary circle that the tow aircraft flies. For this the glider nose needs to point towards the outside/higher wing of the tow-plane and the vertical stabilizer of the tow-plane should point slightly to the outside of the turn compared to the fuselage. Look for the beacon light on top of the fuselage and compare it to the tip of the stabilizer. The stabilizer tip should be slightly on the outside of the turn.

When you have lost sight of the tow aircraft immediately disconnect. Otherwise if you have reached the desired altitude you can release as well.

• Check that the airspace is clear to the right of you
• Click on the yellow hook release handle in the cockpit or
• Use assigned the key/button to release or
• Press the button on the screen overlay.

Activate the release a total of three times. Then

• Perform a right hand turn away from the tow and maintain visual separation
• Go through the after takeoff checklist like for the glider winch launch.

The tow aircraft then descends and attempts to land back at the field.

To select the glider self launch

• Select a glider with an engine in the aircraft menu first, e.g. the Antares 21E
• Find your desired airfield, in our example: Farrenberg
• Click on the yellow glider symbols OR
• Click on the yellow airplane symbol on a runway
• Select self launch is selected on the right side
• Return to the main menu
• Start the flight

In the simulation:

• Set the flaps to the self launch position (+2 in the Antares 21E)
• Set the pitch trim for self launch (about 0-20% up works well in Aerofly FS)
• Use the assigned glider-engine controls to extend the engine or
• Drag the throttle lever in the virtual cockpit forward to 25% to extend the engine pylon.

Wait for the extension to complete before continuing. In a combustion engine you would now start the engine, perform the magneto checks, etc. but in our fully electric glider this is not necessary.

When ready for departure

• Hold up elevator to prevent the nose of the glider to touch the ground
• Check that spoilers are retracted
• Move the throttle lever all the way forward to apply full throttle
• Check that there are no cautions or warnings on the EDCS and check the RPM is normal, otherwise abort the takeoff immediately by reducing throttle back to idle.
• Maintain direction with the rudder and the steerable tail wheel and lift the wings off the ground as soon as possible and hold the wings level.

When airspeed starts to rise

• Reduce elevator back pressure so that the aircraft starts rolling on the main wheel
• When the glider lifts off avoid pitching up quickly, instead let the airspeed build up and let the glider fly away from the ground on its own.
• Allow the glider to weather-vane into the crosswind.

On the airspeed indicator you can see a blue line which indicates the ideal airspeed for climbing.

• Pitch up or down to maintain the ideal climb airspeed (blue line)
• Use pitch trim to reduce constant elevator pressure
• Monitor the remaining battery charge, voltage and temperature
• Stay within the pattern to allow an easy return in case of an engine failure
• Check the surrounding for other traffic
• Above about 150-200m AGL select gear up and turn up the variometer volume

• Increase airspeed to about 110-120km/h and trim for this airspeed
• Move the throttle lever to the 25% idle/stop position
• Monitor the decreasing propeller RPM on the EDCS and check that the propeller stops.

The drive system now automatically rotates the propeller to be aligned properly for the retraction.

• Move the throttle lever to 0% to retract the pylon.
• Adjust flaps and trim for the flight.
• Check gear is retracted.
• Adjust variometer volume