paragliding

Brakes: Controls held in each of the pilot’s hands connect to the trailing edge of the left and right sides of the wing. These controls are called 'brakes' and provide the primary and most general means of control in a paraglider. The brakes are used to adjust speed, to steer (in addition to weight-shift), and flare (during landing).

Weight Shift: In addition to the manipulating the brakes, a paraglider pilot must also lean in order to steer properly. Such 'weight-shifting' can also be used for more limited steering when brake use is unavailable, such as when under 'big ears' (see below). More advanced control techniques may also involve weight-shifting.

Speed Bar: A kind of foot control called the 'speed bar' (also 'accelerator') attaches to the paragliding harness and connects to the leading edge of the paraglider wing, usually through a system of at least two pulleys (see animation in margin). This control is used to increase speed, and does so by decreasing the wing's angle of attack. This control is necessary because the brakes can only slow the wing from what is called 'trim speed' (no brakes applied). The accelerator is needed to go faster than this.

More advanced means of control can be obtained by manipulating the paraglider's risers or lines directly. Most commonly, the lines connecting to the outermost points of the wing's leading edge can be used to induce the wingtips to fold under. The technique, known as 'big ears', is used to increase rate of descent (see picture and the full description below). The risers connecting to the rear of the wing can also be manipulated for steering if the brakes have been severed or are otherwise unavailable. For groundhandling purposes, a direct manipulation of these lines can be more effective and offer more control than the brakes. The effect of sudden wind blasts can be countered by directly pulling on the risers and make the wing unflyable, thereby avoiding falls or unintentional takeoffs.

Fast descents

Problems with “getting down” can occur when the lift situation is very good or when the weather changes unexpectedly. There are three possibilities of rapidly reducing altitude in such situations, each of which has benefits and issues to be aware of. The "big ears" maneuver induces descent rates of 2.5 to 3.5 m/s, 4–6 m/s with additional speed bar. It is the most controllable of the techniques, and the easiest for beginners to learn. The A B-line stall induces descent rates of 6–10 m/s. It increases loading on parts of the wing (the pilot's weight is mostly on the B-lines, instead of spread across all the lines). Finally, a spiral dive offers the fastest rate of descent, at 7–25 m/s. It places greater loads on the wing than other techniques do, and requires the highest level of skill from the pilot to execute safely.

آموزش پاراگلایدر
Paraglider in "Big Ears" manoeuvre
Pulling on the outer A-lines during non-accelerated, normal flight folds the wing tips inwards, which substantially reduces the glide angle with only a small decrease in forward speed. As the effective wing area is reduced, the wing loading is increased and it becomes more stable. However the angle of attack is increased and the craft is closer to stall speed, but this can be ameliorated by applying the speed bar, which also increases the descent rate. When the lines are released the wing reinflates. If necessary a short pumping on the breaks helps reentering normal flight. Compared to the other techniques, with 'big ears' the wing still glides forward, which enables the pilot to leave an area of danger. Even landing this way is possible, e.g. if the pilot has to counter an updraft on a slope.
B-Line stall
In a 'B-line stall', the second set of risers from the leading-edge/front (the B-lines) are pulled down independently of the other risers; with the specific lines used to initiate a stall. This puts a spanwise crease in the wing, thereby separating the airflow from the upper surface of the wing. It dramatically reduces the lift produced by the canopy and thus induces a higher rate of descent. This can be a strenuous maneuver, because these B-lines have to be held in this position and the tension of the wing puts an upwards force on these lines. The release of these lines has to be handled carefully not to provoke a too fast forward shooting of the wing, which the pilot then could fall into.
Spiral Dive
The spiral dive is the most rapid form of controlled fast descent; an aggressive spiral dive can achieve a sink rate of 25 m/s. This maneuver halts forward progress and brings the flier almost straight down. The pilot pulls the brakes on one side and shifts his weight onto that side to induce a sharp turn. The flight path then begins to resembles a corkscrew. After a specific downward speed is reached, the wing points directly to the ground. When the pilot reaches his desired height he ends this maneuver by slowly releasing the inner break, shifting his weight to the outer side and braking on this side. The release of the inner brake has to be handled carefully to end the spiral dive gently in a few turns. If done too fast, the wing translates the turning into a dangerous upward and pendular motion.
Spiral dives put a strong G-force on the wing and glider and must be done carefully and skilfully. The G-forces involved can induce blackouts, and the rotation can produce disorientation. Some high-end gliders have what is called a "stable spiral problem".[24] After inducing a spiral and without further pilot input, some wings don't automatically return to normal flight and stay inside their spiral. Serious injury and fatal accidents did occur when pilots could not exit this maneuver and spiraled into the ground.

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