Hello! My name is Owen and I was a paragliding instructor in England for a number of years. Nonetheless, all information supplied here is merely referential, not advisory, and any actions you take are entirely your own responsibility. Paragliding is a hazardous sport, and you should check with a fully qualified instructor before attempting any of the following manoeuvres. If you have not qualified at a fully endorsed and licensed school then you have no business being in the air, except as a paying passenger.
This article is about rapid descent techniques. As paraglider pilots we spend most of our time trying to get up, and a very small amount of time trying to get down. Unfortunately the times that we do want to get down are usually the most serious, and all the praying in the world won’t do any good; good training and pre-planning will. If you get yourself into a situation where you have to use a rapid descent technique then you have already stuffed up, but we’re dealing with an invisible element here, so that’s not hard to do.
The most commonly taught rapid descent technique is Big Ears. As this is usually taught in schools it is commonly regarded as being a safe technique, which it mostly is, but I have seen it go very, very wrong on more than one occasion. Changing the shape of your wing from its optimal flying form is a risky process, but it can be better than the alternative if conditions have changed. Most accidents with the Big Ears technique occur because of bad training or a lack of understanding of the forces involved. Here are a few points to bear in mind (though these suggestions are constantly updated, and so should definitely be verified with a current instructor):
- Each “ear” should be pulled in one at a time, not together. This point is debatable, but as the main danger of pulling in the ears is that the angle of attack is increased (due to the glider descending at a steeper rate), pushing the glider closer to stall-point. It is therefore preferential to lessen the sudden change in angle of attack by taking it in stages, one ear at a time. You will often see pilots pulling in both ears together, but this can go disastrously wrong, as I have personally witnessed.
- A good way to reduce the angle of attack is to use you speed bar. Before pulling your ears in you should make sure your foot is resting in the speed bar stirrup, and then once your ears are in and your wing has stabilised to push out on the bar, though not necessarily to full stretch. Be careful not to use your bar before pulling your ears in, or you could get a front tuck.
- The wind gradient is your enemy in this case. You may well be using big ears because of increased wind speed, but it is the descent through the wind gradient to lower wind speeds that can cause a deep stall, brought about by the increased angle of attack. A deep stall at low levels is very dangerous, because you do not have time to recover. Again, speed bar can help to prevent a deep stall, but remember that it is when you think that you are near to safety that the danger is at its greatest.
- DON’T pump your ears out. This technique used to be taught in schools (pumping the brakes to exit Big Ears), but it is now comprehensively discredited. Pulling on the brakes would increased your angle of attack further, putting you closer to a stall. To exit, simply release the a-lines and allow the ears to unfurl themselves. On some higher performance gliders the ears may stay in, so if you’re flying anything over a DHV 1/2 glider READ THE MANUAL before you fly the thing.
This manoeuvre is intended for use at a good height (over 500 feet at least) only, and should not be used close to the ground. The danger is that the glider will not recover and will enter a deep stall. To recover a deep stall you should apply some speed bar, which will decrease your angle of attack back to normal flying range, but at low level this may not be an option. B-line stalls are for escaping cloud suck, not for landing.
Spiral dives are also an up-high method of descent, and not for low landing. Spirals are very disorientating, and it is possible to black out due to the g-forces involved. Another danger is lock-in, where the wing will not come out without pilot input (or may actually tighten in the turn when the brake is released), which coupled with the disorientation and speed of descent might mean a big, you-shaped hole in the ground. In theory entry-level gliders should pull themselves out of spirals quickly and automatically, but recent evidence suggests that this is not always the case, due in part to variable factors, such as pilot height, weight, centre of gravity, and whether or not you are using a cross-braced harness.
Another problem with spirals is that unless you know what you are doing with them, and bad exit can land you in more trouble than you started with. Spirals need to be exited slowly, because otherwise all of the energy (and there’s a lot of energy involved in a spiral dive!) gets converted to lift, and your wing goes behind you and then dives in front. Assymetrics can easily occur at this stage, and before you know it your wing is performing its own improvised spiral and you’re along for the ride. Scary.
Tight turns (wingovers)
Tight turns will get you down, but your wing is inherently unstable in the process, and coupled with the wind gradient and any low-level turbulence you might encounter, you’re just asking for a collapse. Not recommended.
Pilot-induced asymmetric tuck
Similar to Big Ears,this technique involves collapsing just one side of your wing. This means that you have no real options for reducing your angle of attack, and the side of the wing that is still flying has a much higher angle of attack. Also if you collapse too much of your wing at the wrong moment, you may end up with a full frontal, or a collapse-induced spiral. Big Ears is the safer option, which is why it is taught in schools.
All in all Big Ears comes across as the safest rapid descent technique for low-level flying, while B-line stalls are the most useful for high-level stuff. Any of the above techniques should not be attempted for the first time when you need them, but in schools or on properly-run SIV courses over water, with a recovery boat in attendance.
The main danger with any of these techniques is ignorance, especially with Big Ears, which is so often performed incorrectly due to pilots not keeping themselves up-to-date with the latest developments in the sport. Remember: you may be a qualified pilot, but the sport is still young and the air unforgiving. Keep current.Immobilienmakler Heidelberg Makler Heidelberg
Source by Owen Webb