How to anticipate and counter them?
Collapses happen in many ways but must be managed by the pilot. The sudden change of incidence of the wing causes a loss of dynamic flow, and the profile (leading edge) collapses.
There are generally two types of collapses: asymmetric (one side of the wing only), and symmetric (called "frontal").
Two profiles can be distinguished, the cross country pilot and the aerobatic pilot:
- In the case of the aerobatic pilot, by performing manoeuvres and often changing his profile, the pilot is attentive to the potential for collapses. He is therefore ready to anticipate this collapse. Usually the pilot is away from any obstacles and has enough margin from the ground to manage the incident. This pilot will have collapses if his movement is not good, so he is totally vigilant on this point.
- In the case of the pilot flying in thermals or cross country, his attention is focused on other matters. His vigilance on this point is therefore diminished, which is why the pilot is surprised when the incident occurs. If our attention is diminished, we must compensate by increasing our margin with respect to the ground, which is our guarantee of safety, which leaves us time to analyse the situation and react accordingly.
How to anticipate a collapse?
It is difficult to anticipate a collapse when you have a low level of flying experience, because our notions of angles and axes are weak and therefore far from under incidence. The only way to learn is to inflate on the ground and play with the pitch of the wing. By forcing these angles to find lightness at the controls and some wing crumpling, you will learn to feel the different pressures at the controls and anticipate the under incidence.
Afterwards, you will have to make the transfer in the air, and for that you have to relax, because the muscular suppleness will offer you a better feeling and more fluid actions of control.
How to counteract?
Countering is the generic term, the most important thing for me is that the collapse does not trigger rotations. If there is a rotation, then you have to counteract, stop the acceleration, either by a harness transfer or in addition a brake action on the open side. These piloting actions must be measured and adapted over time.
Autorotation or wing that generates its own rotation and continues until the pilot acts correctly.
This phenomenon combines two things: the collapse and the rotation (360 engaged!), it is therefore necessary to be at ease with the piloting that goes with it.
Several causes are possible, a basic collapse on a roll out of a thermal, the ear of the wing gets stuck, the rotation starts because the pilot tries to open the wing instead of stopping the rotation, the rotation accelerates, the ear is more and more stuck and the phenomenon centrifuges the pilot. In this case, you have to think about the rescue parachute!
There is a choice to be made by priority:
1. I stop the rotation.
2. I take care of the collapse by using a fast brake amplitude on the closed wing.
Anticipating an autorotation?
It is easy to anticipate, it is the logical consequence of a collapse. No collapse, no autorotation!
The advice is often this:
1. Don't trust your glider, act if you recognise the situation (many pilots let it happen under the pretext that the glider is in category A!)
2. Never underestimate the size of the collapse. The size is a detail that you see, but you forget the most important thing which is the position of your body and the wing in space. It is often this that instantly increases the base acceleration.
How do you counteract it?
First of all, when it comes to rotation, you need to be comfortable with committed 360's, the more control you have the more reliable your ability will be in this condition.
"Auto" means that the wing decides its trajectory, it is impossible to imagine a "paragliding google map" or a "paragliding Waze" so if the trajectory is not good, you must act as a pilot.
Unfortunately, autorotation is a frequent incident, as the pilot flies in conditions inappropriate for his level of active flying. If this ever happens to you and you feel that you do not have the technical or physical ability to withstand the spin, then use your reserve parachute. This will solve your problem at the time.