Dealing With Deflations
They happen to all of us from time to time and all gliders are susceptible to having them. It is without doubt one of the main causes of accidents but often it is not the deflation that really causes the problem it is the reaction of the pilot in trying to control the situation.
Over the years of my involvement in paragliding I have witnessed many accidents and incidents, some of which have lead to serious injury but in many of the cases injury could have been avoided.
Once you’ve taken a deflation your reaction, or sometimes lack of reaction, is crucial to the recovery of your wing, so let’s take a closer look at what actually happens during a deflation and consequently your best line of defense to avoid a serious incident.
Our pilot, Edward, has about 300 hours amassed over four years. He flies a DHV 2 glider that he moved on to last year, and he now has about 50 hours on it. So far his best cross-country has been 65km in the Alps done last summer. He only gets to fly at weekends and holidays, much to the frustration of his wife. But all the same he feels relatively happy flying in thermic conditions unless it gets rough then he gets a little nervous.
Edward gets up late on the day in question and stuffs his breakfast down before rushing to take off as fast as he can. *He doesn’t bother checking the weather forecast as it’s a clear blue spring day that looks great for flying and he doesn’t want to be even later to launch than he already is.
When Edward launches at midday there is just a light breeze up the face and the first thermals are nice, smooth and easy. But after an hour in the air the day begins to change fast and the thermals become strong, even a little rough. *Although he’s not enjoying it much he decides to carry on flying as he’s desperate to break his personal record of 65km. *On top of that his flying partner, Winston, is in the air only a few kilometres ahead and there is no way he is going to let Winston beat his personal record.
High above the mountaintops Edward starts getting in to trouble, it feels like the wind has picked up and the thermals are now strong, broken and rough. *Edward feels his palms sweat, his heartbeat quickens and he gets that feeling in his stomach that he doesn’t like. *He becomes nervous and tense, his normally smooth reactions turn into nervous sharp movements as the wing flies through the turbulence. *He begins to sit up and forward in his harness. He doesn’t know why he does this but he always does when it gets bumpy, windy or when he gets scared.
Then the big one gets him, Edwards’s leading edge folds under as the turbulent air engulfs his wing and deflates it. 60% of the wing folds under and back before he can even think. Edwards’s heart is now in danger of exploding as a surge of fear runs riot through his mind and body. *React, react is his only thought so he jams on the left break to counter the deflated right wing. His input is far too aggressive and he pulls far too much brake and consequently he accidentally spins and stalls the wing. He is now in some sort of unrecognizable stall / spin. Frantic by this point he releases the brake and the wing shoots forward past the horizon so fast that he worries that he’ll fall right over the top of the wing. He slams down on both brakes on to try and control it and again the wing falls all the way back behind him. Edward is now a panicking mess of flailing arms and legs. *Time and crucial altitude is lost as he falls through the air trying to work out what the hell his wing is doing as it shoots forwards, backwards and side to side.
Smack, crunch, crack, Edward comes back to mother earth and his personal best of 65 km’s will now stand for ever!
Note the pilot’s body position leaning into the tuck
What actually went wrong for poor old Edward?
Take a look back through the scenario and look for the *’s in the text and you’ll quickly find his mistakes.
- Edward didn’t check the weather. If he had he would have known that there was an inversion that would break in the early afternoon, explaining why the thermals suddenly got stronger. He would have also found out that a front was expected that evening and the winds were forecast to pick up in the afternoon.Never take the weather for granted. It is a highly complex subject and it’s very important that we as paraglider pilots fully understand it as we have a very small flight window as we fly so slowly and suffer deflations in rough air. Understanding the weather is the primary key to staying safe. Read books and study it on the TV and Internet. You need to understand pressure charts, dew points, lapse rates and much much more. After all my years of flying I am still learning and I still have the ultimate respect for the power of nature.
- Your ego and desires are your enemy. When flying your only goal should be to fly safely and enjoy it; you have the rest of your life to beat your own records. You should never push yourself past your own limit. Your body tells you when this is happening by making you feel uncomfortable and nervous, so listen to it. It’s a warning that you are entering an area of uncertainty, enter only if you have the ability but go and land if you are even unsure.
- Ego again, this time involving others. Never try to push yourself because of others. Winston has been flying for seven years and has about 1200 hours. He’s flown all over the world, even in some competitions and has done well. Everybody is different so fly by your standards not anyone else’s, and don’t compare yourself to others; they might be out of their depth as well.
- All the warning signs are now flashing yet Edward continues – this is his really big mistake. Once you’ve stopped enjoying your flight, go and land. This is when we start really getting out of our depths and when we often make more and more mistakes. Fear can cloud our judgements, our reactions can become random and often incorrect and you might even lose some co-ordination. Try to keep breathing, try to relax, stay cool and just keep flying the glider down to a safe landing the way you normally would. Getting down safely is the best form of accident avoidance at this stage.
- Sitting forward will not help you at all; in fact it does the opposite. You have moved into an abnormal position for an abnormal situation. It is much harder to fly a wing perched on the edge of your seat, which is why we fly reclined. It reduces sensitivity and makes it hard to look up at your wing. Try to stay in the position you normally fly with, as this is obviously the position that you are used to controlling the glider from. Reduce the variables do not increase them.
- Only react if you understand the situation so you can be sure that your reaction is the correct one. Still to this day people will tell you to counter a deflation by weight shifting to the opposite side and applying brake. Although in theory this sounds great in practice but it’s a very difficult thing to do correctly.When you have a deflation your wing loading increases dramatically on whatever part of the wing remains flying, consequently the stall speed increases due to the extra loading. By weight shifting even more on to the flying side you increase the wing loading further still.As the wing loading increases so your stall speed goes up too, and reduces the brake travel, then add the drag that the deflated side brings to the equation and you are probably already very close to the stall point. At this stage many of the textbooks would tell you to add brake to counter the turn.However applying any amount of extra brake at this stage can easily stall the wing. In fact if you are flying with deep brake already (thermalling slowly), when you take a big deflation you may already be beyond the stall point. You may have to lift up a bit to let the wing fly and prevent it from stalling.You’ve probably all heard pilots say after an incident « I hardly even pulled the brake and the glider just stalled / spun ». This is due to the kind of classic ‘over correction’ that Edward experienced which can stall the remaining part of the wing and sent the glider into a nasty ‘pilot induced’ cascade.At this moment you are probably pretty scared, sitting in the wrong position and in no fit state to find the smooth, precise and controlled motor skills required to sort out a situation like this. The ironic thing is this is often when pilots decide to throw their reserves, the wing almost always opens and try’s to fly again, because when they let go of the controls to get the reserve handle the wing had a chance to sort it’s self out. By this time it is normally too late as the reserve is already out the bag and inflating.My advice is not to weight shift at all, but just to apply a small amount of brake to the flying side just to slow down any rotation, not to stop it. In the vast majority of cases the wing will fully open itself within 180 degrees. If not one big smooth pump on the deflated side should do it. By not weight shifting to the opposing side you allow the wing to accelerate at it’s own pace and continue in the direction it wants to go. This energy helps the glider stabilize due to the inherent pendulum stability that is built into a paraglider. In my view it is far better to let the wing do this rather than chance over correction and ending up in a much worse situation than you started in.I only use the countering technique if I am close to the ground or in danger of hitting someone. The rest of the time I let the wing do what it wants until it stabilizes in some form of flight (might be a spiral dive) that I recognize and then I fly it out just as I normally would.
- Altitude and time are lost at moments like these; the brain can be so confused that you almost forget where you are. Do not spend all your time looking at your wing, keep a very watchful eye on your altitude; it is the only important thing at this time.
- Edward did not throw his reserve! He has the rest of his life to wish he had. One of the reasons I am here today is because I have never been scared of using my reserve. If you crash from an altitude of over 100 meters high and your reserve is still in it’s bag, you’ve wasted your money. There is no disgrace in using it and they do work very well, so please use it if you are out of control or too low to chance it – that’s why you carry it.
My view is not a just a theory, it is something I’ve learnt through years of testing wings, and even more years of seeing it happen and having it happen to me. My heart still pumps in a ‘live combat’ situation but I know the wing I fly and understand its reactions enough to still be able to relax and sometimes even enjoy the ride if it’s not too outrageous. Also the years of testing have really confirmed that in a lot of situations the best thing to do is very little apart from observe and wait until I see something I recognize.
Remember that all the DHV test results up to DHV 2 involve NO pilot input. That means that the wing recovers on it’s own – so no need to mess with it that much. I tell my friends who are not professional pilots that the best thing they can do in a bad situation is to do nothing at all until there glider is in a state that they recognize before they try to take control again – providing they have sufficient altitude to recover. I know it sounds outrageous but it really can be better than over reacting.
Your biggest danger is to overreact and end up in a cascade where every aspect is out of the normal and you have no experience or training to deal with it. Ok, you went to a SIV course, good I hope you had a nice holiday and enjoyed the ride. This is by no means enough training and nor does it feel like a ‘real combat’ situation, where the invisible enemy launches a surprise attack at 400m high above a rocky ridge. It gave you a taste of what can happen, over water, with a person on the radio telling you what to do and when. You would need to go once a month to become proficient at controlling and understanding these situations. On top of that, a real air deflation has a very different reaction to a self induced one.
Remember, the best form of safety is still to stay on the ground if you are in any doubt. If you are already flying, go down and land; there is always tomorrow to have a great flight. If it is to late then try relax and don’t overreact; take a moment to look at what’s happening but if you’re low and in a mess throw your reserve.
I am sure that this Flying Tip will cause some discussion – great, even if you disagree it has got you thinking and thinking leads to understanding.
Safe flights to all,