PARAGLIDING TAKEOFF (HILL)

PARAGLIDING TAKEOFF (HILL)

by Nikolay Yotov – November 2023

Paragliding takeoff has three main stages:

  • Raising and inflating the canopy
  • Controlling the wing
  • Accelerating and loading the wing

The main goals of raising and inflating the canopy stage are:

  • quick and symmetrical rising up to vertical position above pilot;
  • quick inflation of the canopy during its rising;
  • preparing for the control stage.

The clean and symmetrical inflation of the canopy is a direct result of its correct layout on the ground. In light winds, experienced pilots prefer to kite their wing, raising it up 2-3 times, making sure everything is clean. In stronger winds, building a wall is a good and cautious way to inspect lines, canopy, symmetry and wind. In no wind we have to prepare the wing manually: thoroughly, stretching and combing the lines; walking along them to inspect them for knots and twigs. Then lifting them up to check if they are catching on any vegetation, stones, or the ground. Going back to the canopy as it’s often deformed or folded from line checks. Pulling the central part of the leading edge backward and the brakes forward, so it looks like an arc and inflates the central part first, reducing the potential asymmetrical rising of the canopy. Finally, attach the harness to the risers and check again the wind, and whether the canopy is perpendicular to it, clean and symmetrical.

Beginner pilots usually need more time to prepare their wing, so they usually do it without being in the harness, which stays aside. Then, they go and prepare themselves in the harness, but meanwhile even a light wind gust may mess up their wings, so they should disconnect from the harness and prepare the canopy again.

There are some pilots, beginners and experienced alike, who keep their harness permanently connected to the canopy risers. From one side, this reduces the mess in lines and makes the spread wing more resistant to light wind. On the other hand, the harness is heavy enough to make the paraglider fly itself, so be careful in strong or gusty winds, don’t leave the wing unattended. The heavy harness is uncomfortable to lift up and move around, so pilots often neglect their line checks and omit the useful kiting of the wing.

A common practice is to prepare your wing somewhere calmer, not blocking the takeoff space for others. Then, attach yourself into the harness, and don’t forget the leg straps. Connect properly to the wing, mushroom it, carry it on your shoulder to the takeoff zone and spread it out, while staying connected in the harness. You can ask other pilots around to help you with this.

If a wind gust or dust devil comes during the preparation, grab and pull the rear risers, where the brake pulleys are – to prevent any unintentional inflation, wing flying or any dragging of you across the ground. If you see such a situation with someone else, then quickly jump and grab the sail at its wingtip.

Once the canopy is checked and properly laid out, with the pilot connected correctly in the harness, the pilot should then do a final pre-flight check. The logic here is to check from the inside to outside, starting with the most important aspects, pronouncing aloud each element’s name and its status.

Pre-Flight Check

  1. HELMET – Connected. It should be on the pilot’s head with its buckles connected. Not too tight, but not too loose. The helmet should be on the pilot’s head before they get into the harness. There has been serious head injuries with pilots in their harness connected to their wing, when for example a gust of wind activates the canopy and throws the pilot down on to the ground and drags them through obstacles.
  2. LEG STRAPS – Left. Right. Connected. There have been, and unfortunately will continue to be, fatalities of pilots, who took off and fell out of their harness, because they didn’t connect their leg straps. When checking your harness buckles or carabiners, try to pull them apart with your hands imitating the loading during flight, to check if they are connected and locked properly. Never rely on the clicking sound only, as the locking mechanisms get worn out with usage. Dust, sand or small debris can compromise these mechanisms.
  3.  CHEST STRAP – Connected. You may survive a flight with an unlocked chest strap, but it does set the distance between carabiners, which is important for a paraglider’s geometry and behaviour.
  4. CARABINERS – Left. Right. Connected. There are various carabiners with different locking safety systems, which usually require 2-3 movements (twisting, sliding, bending, screwing) to prevent any unintended opening during flights. Make sure they’re properly locked and in a vertical position, carabiners are much weaker when being pulled on sideways. Any incorrect (sideways) position of the carabiners also compromises the locking mechanism and risers, which might be deformed and loaded asymmetrically.
  5. BRAKE LINES – Left. Right. Clear. Each brake line should go from the last riser’s pulley directly to the handle in the pilot’s hand.
  6. A-LINES and LEADING EDGE – Left. Right. Clear. No other lines above the A-lines. Other lines below should be clean and tidy. Ensure the leading edge and cells are all open, not folded or deformed.
  7. AIRSPACE – Clear. No one else intends to take off around, in front of or behind you. There are no other paragliders in the air, who may try to top land on the takeoff. A pilot who takes off should shout “TAKEOFF” to warn other pilots around.
  8. WIND AND SYMMETRY – Good. A few minutes may pass, from the beginning of the canopy layout to the end of the final checks. Make sure the wind hasn’t changed its strength and direction significantly before taking off with the current layout. If it does, either wait or lay out your canopy perpendicularly to the new wind direction. Do your checks again from the beginning. Many accidents happen because of laziness.

Raising and inflating the canopy

 The raising and inflating the canopy stage has three sub stages:

  • initial pull impulse
  • raising
  • slowing down

The initial pull impulse is needed to overcome this unstable stage quickly when the wing is at a stall mode with 90⁰ angle of attack. It’s done by a sharp and hard pull of the wing. The big pull force comes from powerful leg muscles, shoe friction and body leaning forward, pushing with the chest strap. The force goes through the carabiners, pulling directly on the wing’s risers.

Beginners often try to raise the canopy using their arm muscles, but they’re too weak for the wing’s force and may cause asymmetries. The arms should be semi relaxed , pulled by pilot’s body. The hands just hold strong the A-risers and brake handles. The idea of holding the A-risers is to shorten them compared to other risers. This increases the curve around the wing’s nose and its inductive ability which is needed for the initial raising of the wing. Some wings, in some conditions, can be raised without holding the A-risers, but it’s always easier to use them. Some schools teach pulling the risers with bend arms and hands in front of your shoulders. This creates a lever – the entire pull force goes through a higher and further point, which requires more effort (shoulders vs. carabiners). 

The pilot’s pull moves the canopy through the air and creates an airflow around it. Part of airflow enters the canopy through the cells’ openings, pushing its top surface upwards from the inside. Another part of this airflow goes inside for inflating the canopy. The airflow above the nose curve accelerates, reducing the pressure there, which creates a forward aerodynamic force RT lifting the wing vertically.

            When the leading edge rises about 2 meters above the ground, the entire bottom surface becomes fully exposed to airflow, creating an enormous drag force. The pilot might be surprised by this force, which is even bigger, if there is some wind. Experienced pilots know how much to lean their body forward for the given wind conditions, in order to resist the drag force from the bottom surface. If the wind is strong, then it may not be possible to travel forward, but it’s the pull force which raises the wing, not the forward progress on the ground. The wing can be perfectly raised above us, even if we walk backwards.

A common beginner’s mistake is to give up the forward pull, when a big drag force pulls them backwards. The pilot should focus on the pull force, applied through the carabiners, and control it with legs’ muscles and the body leaning in a forward position, no matter if you are walking forward or backward.

After the initial pull impulse stage, things become easier. The wing continues rising, rotating around the carabiners and reducing its angle of attack. The canopy’s bottom surface exposure starts decreasing its big drag force. The inductive ability enters a more favorable angle of attack, and its tangential force RT accelerates the wing forward. The pilot still needs to hold the A-risers because the extra curve around the leading edge is still needed for the inductive ability. 

In no wind conditions, the pilot should continue to pull and walk forward. In light wind, he may stay in one place, using his body mass inertia to fix the wing in the airflow. The pull force – the tension in the risers and the lines, is still there and the canopy continues rising, еven without much pilot movement. In stronger wind, the pilot may need to make 3-4 steps backward, but the wing will continue rising normally, if he keeps the same tension in the lines, like in no wind or in light wind conditions.

With the rise of canopy, the pull force becomes more vertical and the pilot can use more of his body’s’ weight force G and less of his leg muscles and body leaned forward.   

Often, during the canopy raising stage, the wing may rise asymmetrically. It could be due to outside conditions, like a change of wind direction or wind gradient effects. It could be due to poor layout, where a line is caught by the terrain or vegetation, or a line knot which can slow down one side of the wing. It could also be a deformed wingtip, too slow a pull or an asymmetrical initial impulse pull.

Experienced pilots are very sensitive about canopy rising asymmetries. The earlier you react to them, the less work you will have later. Of course, if the asymmetry is too big, then it’s not possible to recover it, so it’s better to stop and start with a new layout again.

If the asymmetry is small, then the pilot should feel if the left or right side of the wing rises more and move to the other direction, while keeping the forward pull against the wind. The step-sideways correction usually requires 2-3 steps, but in bigger asymmetries 5-10 steps might be needed. That’s why, it’s good to have a bigger takeoff space for possible corrections. The asymmetrical rising correction needs some practice; beginners are usually in a hard-pull mode and react wrongly on wing’s sideways motion by pulling it in the opposite direction, towards the side which started working earlier and creates bigger drag force. Be tough for the initial forward hard pull, but sensitive to asymmetrical raisings and the following sideways motions. Feed the wing with airspeed, but don’t fight it. Make it go above you with the forward pull, but you also go under it if it tilts sideways. Let the wing works properly first and then control it with brakes.  

A very good exercise is to walk through a field, trying to keep the glider above your head for as long as possible. When the wing goes forward, you speed up forward too, and apply some brake, not allowing it to overshoot you. When the wing goes backward, you raise your hands to a zero brake pull and push with your body forward to feed the wing with airspeed. When the wing goes sideways, you should go in the same direction, keeping under its center. The same like balancing a vertical stick on your finger, plus some inductive ability. Learn not to overreact with your corrections. Build confidence in how the wing works. For example, if the wing goes sideways towards a thorny tree, do not panic and pull it in the opposite direction, as this will destabilize it further, but go under the center of the wing, towards the danger. Make the wing work and then take control with the brake to turn it away.

The last part of the raising and inflation stage is slowing-down-the-raising, preparing for the next control stage, when the wing needs to stay stable above the pilot. Meanwhile, the canopy should be inflated fully and become a properly working wing. The wing, plus the air inside it, weighs about 15 kg, which develops sufficient speed and inertia at the end of the canopy rising stage and needs to be stopped to prevent overshooting the pilot. There are three ways:

  • to decelerate the wing;
  • to accelerate the pilot to equalise his speed with the speed of the wing;
  • to stop the wing by pulling the brakes.

The deceleration of the wing is achieved by significantly reducing the pull force and tension in the lines.

In no wind conditions, this is to slow down your forward walk/run which creates the airflow.

In windy conditions, this is a slight step backward, towards the canopy, just to ease the tension in the lines.

In very strong wind, this easing might be a jump towards the canopy, just after the initial pull impulse; otherwise, the pilot’s body inertia will cause too much tension in the lines and an aggressive self-acceleration of the wing. If this easing of lines is done well then, with the help of headwind, the wing stops above the pilot, and there is no need to use the brakes at all. In light or no wind, the easing might not be enough to stop the wing’s inertia and then it should be stopped with brakes or the pilot should accelerate forward to prevent being overshot by the wing.

Control stage

The main goals of the control stage are:

– stabilizing the wing above the pilot

– providing enough time to check the canopy, lines and conditions

– making the final decision for take off

Once the glider goes above the pilot’s head, it should stay there until landing. The first challenge for beginner pilots is choosing the moment to release the A-risers and pull brakes. This varies with the terrain steepness and wind strength. Don’t try to look up and see when the wing is above you but keep looking forward and focus on the change of tension in the lines. Feel it through the carabiners and harness when it weakens, and when it goes close to vertical. If the canopy is rising faster, then pull brakes earlier, before vertical position. The brakes also are pulled sooner, if you take off in stronger wind, or if the slope is steep, which shortens the wing raising path.

Keeping the wing stable above your head is not an easy job. Sometimes the terrain and conditions make it impossible and you have just a split second to complete the canopy check and make the decision to takeoff. The initial choice of your takeoff spot and moment are important. The wind is alive, so is the wing. A sideways wind gust will push and tilt it sideways, as the pilot on the ground works like an anchor. Move under the center of the wing and then use the brakes to turn it towards the new wind direction. The wing is always more stable when facing into the wind. If the wind is light then this sideways corrections is done during the forward motion which feeds the wing with airspeed.

When keeping the wing above for long periods of time, the experienced pilot is very sensitive to wind changes, using the wing as a sensor. The pilot reacts early with the brakes and body movements, with minimum corrections, without overreacting. Pilot movements may look minimalistic for beginners, but they have a big impact and the result is a wing gently floating above the pilot.

The long-lasting keeping-the-wing-above is easier on a flat ground, just before the terrain becomes steeper. On a steep windy slope the airflow comes from below, creating a constantly high angle of attack for the horizontal wing above the pilot. This activates the inductive ability permanently, the wing wants to fly forward and the brakes need to be pulled a lot, close to stall, to keep it above the pilot. This, close to stall situation, is unstable and the pilot has to decide quickly whether to take off or not.

After checking the wing and conditions, after feeling the harness and its risers, only then the pilot makes a decision for takeoff and accelerates the wing forward.

The main goals of the acceleration stage are:

– accelerating and loading the wing smoothly and fully;

– keeping the wing above the pilot’s head.

            The acceleration of the wing is simple. Just RUN! But run smart, not blind!

            At the start of the run, after the control stage, the pilot releases the brakes fully to allow the wing to acquire maximum airspeed. Higher airspeed means a higher lift force, which means an earlier and safer takeoff.

If the slope is not very steep and wind is light, then the pilot charges fully. The wing is slightly behind, with a higher angle of attack, which is good for its inductive ability to accelerate and start flying forward by itself.

If the slope is steeper, then with each step downhill, the pilot adds significant portions of his body weight. The increasing weight force G pulls the wing downward, increasing airflow from underneath, as well as the wing’s inductive ability, and forward aerodynamic force. Running down a steep slope usually accelerates the wing sooner and stronger, so the pilot may need to run with slightly applied brakes to prevent the wing from overshooting. 

If wind is strong, then the wing starts working sooner and the pilot can take off within 1-2 steps. On good slopes with perfect wind, the wing may work fully during the controll stage, requiring the pilot to hold it with some brakes applied all the time. The takeoff is then simply just releasing the brakes and letting it fly.

A very common beginner’s mistake is sitting down early in the harness. When the beginners feel the first signs of any lift during their run, they think “Oh, I’m flying” and hurry to sit in the harness prematurely. There is also an instinct to shrink your body to the embryo position when something dangerous like a flying happens. For the same reason, some beginner’s grab the risers to feel something solid, to hold on to something. It’s useful for beginners to spend some time on a harness simulator, practicing coming in and out, trusting the risers and overcoming the fears of leaning forward or sideways. The harness is made to hold you even upside down!

The early sitting loads the wing abruptly, it sinks unnoticeably, maybe only 20 cm, but this is enough to activate the mighty inductive ability and the glider may surge forward, overshooting the pilot. If the pilot is still on the ground, then the overshooting can cause a collapse. The pilot needs to stop, pack the wing, hike up and start again with a new takeoff. If the pilot is already in the air, then the overshooting will cause a forward body swing, which can hurl the pilot with high speed onto the ground. And because the pilot has already lifted his legs up, then he’ll meet the ground hard, with his bum, potentially risking a serious spine injury.

Often, takeoff slopes are irregular, with steep parts and flatter parts. The acceleration stage may consist of a series of taking off and touching of the ground, so KEEP YOUR LEGS DOWN, be ready to run fast again! It may look funny, but paragliding instructors are happy when they see their students running in the air for a while after takeoff. The takeoff is the most critical part of the flight because you don’t know the type of air you’re going into. There might be an invisible turbulence in front, which may collapse your wing just after takeoff, so this is another reason to keep your legs down, ready to absorb any impacts. It’s better to break a leg than your back.

Another challenge for beginner’s is to separate their legs from their hands. Our non-flying life has programmed many interconnected motions e.g. when we walk, our right leg goes forward and our left hand automatically goes backward. So, when our legs are running downhill and are dealing with various obstacles, our hands should be able to work independently with brakes; left, right, or both.

Everyone can fly, everyone can take off, but what distinguishes experienced pilots from beginners is take off efficiency.

For example, beginners may recognize with delay that the wing is moving away from them and they are consuming a lot of takeoff space until they control it and adjust themselves under it.  Most takeoffs have limited space and are surrounded by various obstacles. Experienced pilots may recognise if a certain place is launchable for the given conditions. They imagine the takeoff stages and have a virtual stop line if the real takeoff later doesn’t go as planned. Often, there is a herd instinct or various pressures to take off. Know your limits and avoid comparing yourself to others! 

Sometimes, in light winds, you may need to use efficient acceleration / running to take off before any obstacles appear in front of or below you. At the start of the run, you release the brakes completely to achieve sufficient airspeed and then apply a little brake, up to shoulder level, to increase your lift production. Airplanes use flaps for takeoff and landing, which create more lift with less airspeed and less stress for their wheels and structure. Airplane flaps and slightly pulled paragliding brakes fold down the trailing edge, which increase the curve of the profile and its angle of attack. There is an optimum brake position, which will give you the shortest run, for the given wing, terrain and conditions.

If the pilot misjudges the available running space and obstacles come sooner than expected, then a prompt pull of the brakes before them can boost lift production so the paraglider gains 1-2 meters and flies over any obstacles. The boost-of-lift-brake-pull technique works only if the wing has acquired plenty of airspeed, which can be converted into height gain. After the boost of lift, the paraglider loses airspeed and sinks down heavily in order to self-regain its airspeed. So, this technique works only once, and only when there is sufficient airspeed.

            Paragliding takeoffs are usually hills, where the wind is perpendicular to the slope, or there is a plenty of slope for no-wind running. The inflation, control and acceleration stages are easier in winds perpendicular to the slope, because there is a need for less force and speed by the pilot, to create airflow around the wing. It is possible to take off with a cross wind, but prepare for a long run, similar to that done in no wind conditions. The wing’s layout, raising, inflation and control are always into the wind; the first part of running too, but after acquiring enough speed, the pilot starts applying the brake to turn the wing towards the steepest part of the slope, leaving the ground sooner. The flight is possible only if the terrain is steeper than the paraglider’s gliding trajectory. Running diagonally to the slope, reduces terrain steepness and if it matches the gliding trajectory the pilot may run to the bottom of the hill without taking off.

            During the last part of the acceleration stage the pilot is running with increasingly wider steps, with feet barely touching the ground, like walking on the moon. Then, the wing starts carrying the entire pilot’s weight and if the slope is the steep enough, the pilot will take off.

After the take-off, the main goals are:

– supplying enough speed and height for safe avoidance of obstacles around;

– finding the optimal trajectory for safely exiting away from the slope and avoiding turbulent zones. After that, the pilot can engage in adjusting himself comfortably in to the harness! Don’t rush with early sitting, but stay sharp with your controls!

The most common take off mistakes are:

  • Asymmetric rising of the wing because of an asymmetrical layout, etc. If the wing’s raise is too asymmetrical or if there is not enough space for the pilot to adjust himself under the wing, then the take-off should be aborted by stalling the wing with the brakes and stop running;
  • Too late pull of brakes and stopping of the wing during the control stage – the glider overshoots the pilot and collapses;
  • Prematurely sitting in the harness, which loads the wing sharply, accelerates and overshoots the pilot, followed by a high speed pendulum swing close to the ground. A pendulum effect occurs also, when the wing goes sideways from the pilot, due to uncompensated asymmetrical inflation or crosswind gusts;
  • A crash into objects in front of the take-off (trees) due to inefficient and space-consuming take off technique;
  • A crash into objects around the take-off, due to poor glider control (especially in stronger winds).