A Cravat (French for “necktie”) results from having the wing-tip of your glider drop down and get caught in the lines, resembling a poorly knotted tie. The wing-tip is then trapped in an asymmetric tuck, which, if unfixed, can turn the glider, possibly leading to a spiral dive. In the early stage, this configuration can be corrected by controlling your heading with weight-shift and opposite brake and then pulling the stabilo line that attaches to your wing-tip. The stabilo line is usually the outermost B or C line and connects to your wing-tip. Pulling the stabilo line on the cravatted side will pull the wing-tip out. If allowed to go uncorrected ,a cravat can lead to a steep spiral dive. If this occurs, you can still try to slow the rate of turn and get the wing-tip released. However, if you cannot do this before the spiral dive accelerates, or your altitude is low, you should throw your reserve. 

Quick Review

Causes: Large, messy asymmetric wing tip deflations while thermal flying or performing wingovers.

Recovery: Maintain heading with opposite weight shift and minimal braking. Reel in stabilo line until Cravat releases - sometimes this will require several tugs or quick pulls.

Dangers: Large Cravats may cascade quickly into a steep uncontrollable spiral dive.

 

Stalls and spins are situations that result from too high an angle of attack. These can be pilot and/or atmospherically induced (very rare). The most likely scenario is an atmospherically increased angle of attack aggravated by over-controlling by the pilot and exceeding the maximum angle of attack. There is NO WARNING prior to a stall or spin, so your clue should be the position of your hands. If you find yourself flying deep in the brakes, ease up slowly, and let the glider regain air speed. 

A spin occurs when one side of the glider is stalled, and the other side accelerates around it, producing a negative rotation of the glider. A spin usually happens when flying the glider slow and then trying to turn the glider quickly, or when applying too much brake on the inside of a turn. A spin produces a negative rotation and should not be confused with a large asymmetric which will rotate positively towards the deflation. When a glider spins, you will feel as if you are rotating in an office chair. Immediately bring your hands back to the neutral position (trim) and let the glider dive to regain airspeed, checking the surge if necessary. Recovery from a spin, HANDS UP to shoulder level, and be ready to check the surge. By raising your hands to shoulder level rather than the pulleys you’ll be able to react faster to the surge. 

Recovery from a stall can require a lot of altitude, and theories for the best way to recover change periodically. As a novice pilot, you should understand why a stall occurs and how to avoid it. Stay out of conditions that are above your skill level, have correct surge control, don’t fly deep in the brakes, and don’t over react to situations. 

Again: the best way to experience these maneuvers safely is to take a maneuvers clinic or an SIV course when you are ready. A stall is one of only two maneuvers where releasing pressure on the brakes, and letting the glider recover on its own, can be dangerous. The other maneuver is a stable spiral and will be covered in a section later in this lesson. 

Quick Review 

Stall 

Cause: Too high an angle of attack, lack of airspeed, or too deep in the brakes 

Recovery: Consult an instructor experienced with coaching full stalls.

Dangers: Releasing the brakes when the glider is behind you will result in a violent surge. 

Spin 

Cause: Too high an angle of attack on one side of the glider, lack of airspeed, or too deep in one or both brakes. 

Recovery: Release brakes to install the stalled side and dampen the surge when the glider regains airspeed. 

Dangers: Stalling the flying side by applying too much brake or raining to release the stalled side - which will induce a full stall.
 

These kinds of collapses/deflations occur when the leading edge or part of it, has too low an angle of attack and is pushed down or you fly through an area of turbulence. Collapses and deflations are something you will experience if you fly paragliders for any length of time, and usually happen so fast that they are completely recovered by the time you figure out what has occurred. If the whole leading edge of your glider deflates, you would describe it as a symmetric tuck or full frontal deflation. We describe asymmetric folds in terms of the percentage of the wing that deflates. If a small part of the right side of your glider deflated, you would describe it as a 20% to 30% right asymmetric. These terms are more descriptive than the word collapse, and help others visualize and evaluate what actually happened to the glider. 

New pilots tend to spend a lot of time worrying about deflations when they have no need to be. As a new pilot you should be flying in mild conditions that have a low probability of causing any deflations, however, if you find yourself in unforeseen active conditions, remember that being an active pilot and maintaining horizon reference will greatly reduce your chances of having a deflation, and help correct them when they do occur. 

If the asymmetric deflation is large enough, it will alter your course. Using opposite weight- shift and opposite brake will help you maintain your heading and re-inflate the wing. Use mostly weight-shift and only as much opposite brake as you need to control your heading. If you have 1,000+ ft of altitude and the asymmetric turns you 180°, it may be a faster recovery to allow the turn and use the speed and energy of the glider turning to re-pressurize the wing. Too much brake or weight-shift can lead to problems much worse than the asymmetric, use only enough to maintain a safe heading. Be aware that when a glider experiences an asymmetric deflation, its surface area is reduced and your stall speed increases. This means that it will require less brake to stall the remaining portion of the glider. It is very important to apply only enough brake to keep your heading. 

If the tuck is symmetric, you will likely feel the loss of pressure along the leading edge of your glider and in the brakes. The glider will slow down due to an increase in drag, and you may notice an increase in your sink rate. The good news is that symmetric deflations are self- correcting. When the glider slows down, the weight of the pilot continues forward, increasing the angle of attack which re-opens the wing. The glider will surge in order to resume normal airflow. Allow this to happen, only checking the dive if necessary. DO NOT add brake input when the glider is behind you or you might stall it. 

Most importantly, do not overreact. If you are unsure of what to do, do nothing and let the glider sort itself out. You can make the problem worse by giving the glider the wrong input at the wrong time. 

Quick Review

Asymmetric Deflation/Collapse 

Cause: Too low an angle of attack on one side of the glider
Recovery: Opposite weight shift and brake input to maintain heading
Dangers: Over controlling the flying side may cause a full stall

Symmetric Deflations/Collapse 

Cause: Too low an angle of attack on the middle or entire glider
Recovery: Release brakes and wait for glider to surge
Dangers: Applying brake pressure while the glider is behind you will cause full stall or prevent it from regaining necessary airspeed.
 

The first time you experience turbulence it will feel a little disconcerting. Just remember your surge and roll control and carry a little extra pressure on the control toggles, but be aware of the angle of attack of your glider. This will help you feel your glider, and help you prevent deflations. The more you fly, the higher your ‘bump tolerance’ or comfort in turbulence will be. You will eventually become accustomed to it, and will know when it is too rough. If the conditions appear to be very unstable, you should expect a lot of turbulence and should strongly consider whether you should fly at all.
 

The conditions you choose to fly in should reflect your level of skill and experience. Look at the reported and actual conditions and make your decision to fly based on what you know and how comfortable you feel. If flying a new site, get a site orientation if someone is available to give one. If not, plan to spend some time observing the site and the weather dynamics of the area. Most pilots are more than happy to give a site orientation, especially if it means keeping you safe and following site protocols, which reduces the risk of having the site shutdown. 

Once you have decided the weather and site look suitable, it is time to get your gear ready. You should be intimately familiar with your equipment and know if anything needs to be repaired or adjusted. When it comes time to hook in, you should have 100% confidence that your equipment is in top shape and ready for whatever type of flying you plan to do. You may want to spend some time laying your gear out and giving it a quick inspection while monitoring the conditions. This will give you some time to relax, focus, and get a feel for what the weather on launch is doing. 

The final thing to check before flying is yourself. Make sure your mind is in the right place for the task, and that you’re not distracted by personal issues. Flying will require all of your attention, you could compromise your safety, and you won’t enjoy it as much, if you are mentally distracted. Finally, make sure you are flying for the right reasons.
 

The glide ratio, sometimes incorrectly called the “Lift to drag ratio” or “L/D” is the ratio between the horizontal distance covered, and the vertical distance covered. The lift to drag ratio is an indication of aerodynamic efficiency. A glider that produces a lot of lift and very little drag has a high L/D ratio and will travel farther or carry more weight. A glider that produces relatively little lift and a lot of drag will travel a shorter distance. The L/D ratio of a paraglider remains relatively constant while it’s glide ratio over the ground may change dramatically due to rising or sinking air or wind. Most beginner paragliders have a glide ratio of 8:1 in still air, while a top competition glider achieves close to 10:1. 

Maximum Glide is the ratio at which the glider will fly the farthest distance possible. The speed of maximum glide is a bit more than minimum sink. 

Minimum Sink is a term that it used when you are flying your glider with enough brake pressure to slow the decent of the paraglider to the lowest possible rate prior to stalling the wing.

 

A byproduct of lift is a rotating spiral of air that is attached to the wing and travels with the airfoil. At the wing-tips, the vortex, sometimes called wake turbulence, is shed and produces a net descent relative to the air around it. The slower or heavier an air- craft, the more air it must redirect, and the larger the circulation in the vortex. The vortex, like a thermal, is subject to the air around it and can drift with the air-mass for a significant distance. Care should be taken when flying a paraglider in the vicinity of other aircraft as vortices are equivalent to turbulence and can cause deflations. Vortices from powered aircraft and even tandem paragliders with relatively high wing loading can create strong wake turbulence.
 

The angle of attack is the angle created by the difference between the chord line of an airfoil and the relative wind. The chord line of a wing is an imaginary line drawn from the center of the leading edge to the trailing edge. Relative wind is what the wing feels as it travels through the air. Most gliders are designed with the optimum angle of attack achieved at trim or with no extra input on the glider. The angle of attack can be changed by the pilot through use of the brake toggles (brakes) or the speed system. As a non-powered aircraft our deviation from the mean angle of attack is relatively narrow. You should be careful and thoughtful about your gliders angle of attack for both safety and efficiency. 

The chord line and angle of attack change with brake input, or when the wing suddenly encounters a vertically moving column of air. As the angle of attack increases, the amount of lift also increases, up to a point (minimum sink). If the angle of attack is increased beyond “minimum sink” the amount of lift decreases while drag increases until the airflow over the wing can no longer remain attached to the top surface. The lift force is instantly zeroed and the drag vector, in opposition to the flight path, becomes perpendicular to the horizon. 

Beyond the stall angle, the glider is no longer generating lift and the only force slowing your descent is drag.

 

Paragliders like all gliders are subjected to three forces: lift, drag, and weight/gravity. All these forces have a magnitude and a direction. The weight acts through the center of gravity and is always directed toward the center of the earth. Lift and drag are aerodynamic forces and act through the center of pressure. The lift is directed perpendicular to the flight path, and drag is directed opposite the flight path. The magnitude and direction of the lift and drag forces depend on the size and shape of the the glider with payload, air density, and airspeed. 

Lift is generated by “turning” or redirecting the air around a wing. The turning of the airflow results from the air molecules staying in contact with the surface of the wing due to relatively fast moving airflow which generates low pressure regions at the top surface. Think of the wing as “yanking” down on the air molecules above it. We know from Newton that Force = Mass * (Change in velocity / Time). Velocity has a speed and a direction. By changing either the speed or direction of an airflow, you generate a force, in this case, lift. A change in velocity causes a force, and a force will cause a change in velocity. Because the velocity and direction of the air around the wing vary, so do the amounts of lift generated at various points on the wing. The average of those forces is the lift vector. Simply put, the force of a wing pulling air molecules downward into the low pressure at the top surface, generates an opposite force that pulls the wing upward. 

The motion of a glider through the air generates drag. In a powered aircraft, thrust from the engine (kinetic energy) opposes drag. A glider must trade altitude for speed, or trade the potential energy of it’s altitude, for kinetic energy or speed. Thus, gliders must always descend relative to the air in which they are flying. 

Gliders are able to stay aloft for hours at a time because they are relatively efficient and descend slowly. If the glider is subjected to air that is rising faster than its descent rate through the air, the glider will gain altitude and increase its potential energy.
 

As your skills progress so will your ability to recognize and predict weather patterns and conditions. The more information you acquire the easier it will be to develop a model of how the weather and topography in your area interact with each other. You will be able to develop a profile for a good flying day and a bad flying day. 

If you are traveling to an unfamiliar site that you don’t have a detailed profile for, talk with the local pilots about appropriate weather conditions. The locals always know best and some sites can present tricky weather problems that you would only be aware of if you had experience at the site. Trust the locals, even if you see conditions that may look appropriate. They probably know something you don’t.