FreeFlight Advice: The Transition
August 6, 2014
Originally published in Hang Gliding and Paragliding Magazine,March 2014
The word “transition” can be used in talking about many things… but when we hear it in hang gliding it has almost an iconic meaning. We fly our gliders in the prone position, with our hands on the base tube; We land our gliders with our bodies upright, and our hands on the down tubes. To get from A to B we “transition”.
As simple as that may sound, it ain’t! To better understand a topic, it’s useful to ask the W (and one H) question words: What, When, Which, Where, Why, and How. Who is a W word as well, but in this case that is obvious- you, me, whoever the pilot may be.
Starting with WHAT- the transition is working from prone to upright. Does that mean body position, hand position, or both? If I keep my hands on the base tube but rock my body upright, have I transitioned? I would say no, because I can’t really flare with my hands on the base tube, so I can’t be done yet. How about if I move my hands to the down tubes but don’t rock my body upright? Again, I probably don’t want to land like that, so I can’t be done yet. So what I’ve come to realize is that “the transition” actually consists of two elements, sometimes done simultaneously, but often done at different times. Either way can be effective with practice (I use both, depending on the situation).
WHEN to transition is an easy answer: the transition needs to be completed (both parts described above) before it’s time to flare. Unfortunately that is not very specific… because that could be the moment before you flare, or ten seconds after launching. To narrow it down let’s first think about when NOT to transition. There is a specific time in every landing where it is near impossible to maintain control of the glider and transition, and that is on final carrying additional airspeed. With airspeed comes bar pressure, and letting go with one hand while there is bar pressure results in at least a pitch “bobble” where the nose pops up, or worse still an accidental heading change (the one hand you’re still holding on and pulling in with is on one side of the control frame, pulling your weight toward that side and turning the glider). Knowing when not to transition, we can clarify that we want to transition either before we turn on final and then pull in for extra speed, OR near the end of the ground-skim phase of the landing when we’ve bled off the extra airspeed and are nearing trim speed and there is little or no bar pressure.
This pilot opted to transition after turning on final and before pulling in for extra airspeed. Now all she has to do is keep the wings level, round-out, be patient through the ground skim phase and wait for time to flare. Why make landing more complicated than that?
WHICH is the next question we face, because we must choose- transition before final or after ground skim. Both have their pro’s and con’s and neither is a simple choice. Transitioning before pulling in for speed gets the transition done early, leaving you less to have to do while performing your landing. It does however come with a catch- pulling in for speed can be more difficult when flying from the uprights. Notice I said more difficult and not impossible… it CAN be done. In terms of physics, the glider feels your weight hanging from your harness mains and hooked in at the hang loop. When flying prone, pulling in to full arm extension puts the base tube about at your belt buckle, which is just a little farther forward than your harness mains. When upright, we can pull in until the base tube contacts our body… and when it does our harness mains will be just barely behind the base tube. The challenge comes in the anatomical workings of the human shoulder. In the orientation that we hold the down tubes while upright, it’s impossible to pull the down tubes back behind our shoulders. This “problem” is exaggerated in single suspension harnesses that do get our bodies as upright, because it means our shoulders are quite a bit farther forward than our harness mains, and the limits of our shoulders only lets us pull in a little bit. There are a few common “solutions” to this: Because of the rake of the control frame, holding the down tubes a bit lower when pulling in (but return your hands to shoulder level before flaring) moves our hands forward a little more, giving us a little more pull-in. This works better for some than others because of different body types and glider/control-frame sizes. For some, sliding their hands lower just puts their arms at full outward extension and doesn’t help them pull in at all, AND severely handicaps their roll control as well! But for some, this technique works wonders. Another useful “trick” is to use your lower body. Pulling in with our arms moves our body forward as a whole, but what the glider “feels” is moving the center of mass of our body, right? So if you pull in until your shoulders won’t let you pull any more, pulling your legs forward- albeit awkward- moves your body’s center of mass forward more, which tells the glider to fly faster. Looks funny, feels weird, but it works great! A third technique that can help is, instead of holding the down tubes in the conventional way- with your thumbs pointed up- move your hands onto the leading edge of the down tubes and with your thumbs pointed down. This makes it so you can “push” your body forward. This technique can achieve extreme speeds even in the upright position, but there’s a big catch- it adds another step into your landing because you need to get your hands moved back to the trailing edge of the down tubes with thumbs up before you can flare. Personally I don’t favor this method, but some swear by it. There are a few other tricks too, but what’s most important is practicing all of this stuff safely IN FLIGHT. That means getting lots of ground clearance in smooth conditions and getting upright and figuring out what works and how you can fly fast enough from the uprights. Some body/harness/wing combinations can be a real challenge, but it’s a needed skill and worthy of the time and effort to figure it out. It IS possible, but like anything it takes practice.
A look into competition pilot Dustin Martin’s transition in a single-suspension point harness. With his hands still on the base tube he rocks his body upright until the slider on the harness moves forward, and only then does he smoothly switch his hands.
The other side of WHICH is doing your transition late, when the glider is at trim just before you flare. With our hands on the base tube pulling in is a much more natural movement, so many feel they have more control. I’ll agree it is certainly easier to pull in this way, especially for someone that hasn’t put the time in practicing and working out how to fly fast from the uprights in their current gear configuration (we all learned it at some point, but most of us fly different wings and harnesses now). I also know that we’re human, and humans tend to like what they know, feeling most comfortable with things that are familiar. Once we graduate the training hills, we begin accumulating real airtime. Nearly all of this airtime is flying prone and on the base tube. As pilots fly more and more they become increasingly comfortable flying on the base tube… and with that flying upright doesn’t feel as nice. Physics and aerodynamics say we should have equal control over our wing whether upright or prone, as long as we can find a way to shift our weight effectively. All that said, some choose to fly their entire approach from the base tube and move their hands up at trim right before they flare… and there’s nothing “wrong” with that. It is a higher risk option, because it leaves us transitioning (flying one handed) while we are low and slow, with very little margin for error or the unexpected. The MOST risk comes from still flying in the prone position near the ground… even if you prefer to pull in from the base tube, doing half the transition and getting your body upright helps minimize risk because if something goes wrong and you impact, at least you’re not doing it head first. A really nice compromise between transitioning early or doing it late is to get your body upright and move ONE hand to a down tube up high, and leave the other on the base tube. This “one-up-one-down” position feels really secure in rough conditions, and feeling secure helps us stay calm and deal with things as they come up in a smooth and rational manor (which is very important!)
WHERE can refer to “where do we transition”, as in up high or down low (see above)… but I like to think of WHERE will I put my hands. Do I move the left one first, or the right? Am I going to try to move one hand and then the other right after, or sometimes I like to fly an extended period of the approach with one hand up and keep the other on the base tube. There are a lot of options here, and each has it’s situation. The big picture of what we need to accomplish never changes- we control the glider through an approach, carrying speed into a ground-skim, and flare to stop our forward motion. What changes on nearly every flight and landing is what we need to do in order to accomplish that… and that is why there is no one way for all landings.
WHY we transition seems obvious, but isn’t. Most think we need to get our bodies upright so that we get our landing gear under us. However, if you watch a properly flared glider, it rotates nose-up and the keel comes down almost vertical. When flying prone our bodies are roughly parallel with the keel, which means if we stayed prone through a perfect flare we would rotate with the glider and still land on our feet. BUT- as I touched on earlier flying prone near the ground is risky. Also, we have very limited flare authority from that low on the control frame, making timing critical (and unforgiving). With our hands on the uprights, we have much more authority, which means we have more margin for error should we need it. My friend Tom Lanning shared a great video on YouTube of some really talented pilots flaring from the base tube and doing no-step landings in no wind, even on mid-90’s high performance gliders which weren’t the easiest to land. If you think we need to get upright to land on our feet, check it out. Make sure you watch Jonny Szarek not only flare from the base tube, but stick the landing while still zipped up in his pod harness. Anyway, we get upright to minimize risk, to make flaring easier and more forgiving, and in case we need to do a running landing because flaring isn’t an option anymore for whatever reason.
At 0:52 we see the legendary Rob Kells is able to flare from the base tube, on a high-performance glider in no wind. And then at 1:00 we see Jonny Z do the same thing, and stick a no-step landing while still zipped in his pod harness!
Now we can actually talk about HOW do we get the transition done! The thing to remember about the transition is that we are changing body position and orientation. We need to continue flying the glider as we do this, but also do it without unwanted control inputs. Imagine if the glider was a giant bird, we want to accomplish our transition without the bird feeling a thing. Hang gliders are controlled by weight shift, and another way of saying “weight shift” is balance… the key to a smooth transition is keeping your body and glider balanced. There are times when we can let go with one, or both, hands because things are balanced… and there are a lot of times we can’t. The trick is finding- or even creating- those balanced moments. We also need to be realistic in how long or frequent these moments are, which is highly dependent on the conditions. In smooth conditions we might easily get a long enough moment to rock our body upright, transition one hand, and still have time to transition our other hand. In more turbulent conditions, we might need to rock upright during one balanced moment, switch one hand during another, and need yet a third moment to get the other hand up. If it’s really turbulent, those three moments are far apart, which means starting while up higher gives us more time- and a better chance- to complete the transition smoothly. Occasionally we don’t get the balanced moments we needed, and need to create one… which might mean doing part of our transition AFTER we’ve pulled in for speed suddenly sounds like a less-bad option than nearing the ground with both hands still on the base tube. A trick I was taught to keep the glider balanced while letting go with the first hand while there is still bar pressure is, before letting go, slide the hand that is staying on the base tube over to the middle. This way you can use that hand to pull in without pulling your weight asymmetrically and telling the glider to turn.
“The Transition” is, like much of aviation, something that SEEMS simple in concept, but proper execution is a real challenge. It is a time when a lot of landings go wrong, and one way to spot a truly skilled pilot- someone who is able to fly their glider though the entire approach, managing heading and airspeed, and make a complete body and control configuration change invisible. It is a skill that can always use more practice, and any improvements made improve our landing quality and overall safety. This spring, as I work off the winter rust, I will make a conscious commitment to focusing on my transitions… and I will practice them up high first. I’d encourage you all to join me, and encourage your friends to do the same.
Smooth transitions and soft landings in 2014!