FreeFlight Advice: LANDING: Round out and ground skim
December 25, 2013
Q: I’m an H2 and I’ve been having issues with landings since I started. Here are two videos with most of my landings. Thank you for any input.
A: Before we dive right into it, I would like to first thank you for writing in, and for sharing your struggle with the world. Although hang gliding is a pretty small community, I can assure you there are people all over having the same difficulties you are- and your courage and generosity in sharing your experiences will help many!
In a general sense, I see two related-but-separate areas we can improve on. What is probably the more obvious one is your flare timing. Your flare TECHNIQUE actually looks pretty good- you are flaring with arms overhead, and your body “stacked” for maximum weight shift (hips behind shoulders, legs behind hips). On a few flares you don’t hold it out, which would have helped, or you throw your legs/feet forward, which doesn’t help, but overall I like what I see. The timing, however… sometimes you are early, sometimes late… sometimes right on but it isn’t very effective (we’ll get to that). When you’re not getting the desired result even when your timing is correct, it’s really hard to know when that right time is.
The other thing I see that needs immediate improvement is your approaches. Approaches are a lot more important to a successful landing than just “spot landing”. The approach builds the foundation of the landing; without a proper approach a quality landing is near-impossible.
Let’s get a little more specific; Our approach determines where our landing will occur, but also needs to encompass a “final” where we fly straight with wings level and pull in for extra airspeed until just above the ground. As we approach the ground we gradually release that pull-in bar pressure to “round out” and then continue releasing bar pressure as we bleed off our extra airspeed in a ground-skim. Being frank, your landing accuracy needs work… and that is a major safety concern for me as an instructor. But the “secret” to landing accuracy is practice, and we need you having quality landings so you survive that practice- so that will be my focus here. Many of your approaches had a decent “final” where you flew straight wings-level… but the extra airspeed, round out, and ground skim were pretty much nonexistent.
Hard to tell from video, but I hope you won’t mind if I say that you appear to be a small-framed female pilot. Many people are of the belief that small/light pilots have some kind of advantage. I thought so for a long time myself… until I taught my wife to fly (another small-framed female). Being small is an issue in itself- short height can make lifting a glider with wheels a challenge. And finding a proper fitting harness takes a small miracle. Being small also means being LIGHT, which can be a very serious issue in an aircraft that is steered solely by shifting your weight. Less weight means less control! On that note, giving advice online is very difficult- I can not say if your equipment is properly sized and configured, or may be part of the problem. From the look of that harness when you are “upright” something seems off. I’m not sure if that is a used harness that wasn’t made for you or what, but- again only going off what I can see in the video- it looks like you are not getting as upright as would be ideal, and you are also hanging QUITE low, which really hurts flare authority. as for the glider, if you’re around (or under) 130-ish lbs, you should really be flying a glider that is 150 sq ft or less. Modern single-surface gliders handle so well it’s possible for some underweight pilots to fly larger gliders without experiencing any major issues… but the common issue is on landing, when the pilot doesn’t weigh enough (or have long enough arms) to effectively flare. There may be some of that going on here, but it’s hard to say from just seeing video, and especially hard without the round out and ground skim occurring because that could be the main issue.
Understanding the round out and ground skim helps us land better. The round out is the point where you change your glide path from descending to flying level across the ground. When we first pull in for speed, the glider dives steeply. Approaching the ground at this steep angle makes the round out challenging (and riskier), but also uses up more “energy” to effect the greater direction change. Pulling in up higher- which requires a longer final- allows us to pick up that speed up high and approach the ground with lots of airspeed but NOT at a steep angle. This is much easier, and a better foundation for the ground skim. The round out leads to the ground skim, where we bleed off that extra speed before we flare. A proper ground skim means we do not gain or lose altitude, which means the round out needs to occur no higher than we are willing to flare.
Having a long final with plenty of extra airspeed, a smooth round out, and a ground skim phase is crucial to consistent successful landings. The reason is based on physics and the purpose of flaring- stopping forward motion. Flare timing is dependent on airspeed, and happens at or just slower than trim speed. If we approach the ground near trim speed, we are hoping our flare will stop both our forward AND our descending momentum (fighting gravity). This is asking a lot of even the most perfect flare. By carrying speed through our final, conserving it through our round out, we can use that airspeed/energy to eliminate our descending momentum. By having a ground skim, we ONLY have forward momentum to stop with our flare- much more realistic!
In a properly timed flare, the glider should have just enough energy to climb a touch before stalling. I like describing it as a “1/4 loop”. That’s not exactly how it happens, but that’s the best way I’ve found to visualize it. To achieve this, a properly timed flare can and should be a very smooth arm motion. The pitch rate should be the most efficient to transfer airspeed into climbing motion. Flaring very hard rotates the nose up very quickly, but does not efficiently change the direction of our momentum… so it doesn’t stop our forward movement, only slows us down. The right idea is that, by climbing just a little, we transfer our forward momentum into upward momentum- which is quickly cancelled by gravity… leaving us with little or no forward speed.
The climbing slightly “1/4 loop” flare has other benefits as well. What we commonly refer to as “drag” is a mass of air that is being entrained (pulled) behind us. If you’ve ever landed near a wind streamer on a no wind day and seen the streamer show you were downwind just after landing, that is from the mass of air that was following you blowing past you because you stopped and it did not. You see, a stall by definition is a separation of the airflow over the wing. When we stall that entrained air we are “dragging” is released. The “1/4 loop” climbing flare is effective because the glider- and the air following behind it- his an upward trajectory when it stalls and that air separates… which means that mass of air doesn’t slam into the top surface of the glider as you flare and push you forward as you are trying to stop forward movement. The little bit of climb in the “1/4 loop” flare also leads to a very short tail-slide, which creates a very effective rearward force for stopping your momentum.
So- other than some questions as to whether you may be in a glider or harness that is too large for your size/weight (or may be not be configured optimally), I think your flare technique is decent… and the primary cause of your struggle is the lack of a proper approach- not having a fast final, round out, and ground skim- that was making your flare ineffective. If you can work these things into your approaches, a properly timed flare SHOULD stop you and put you on your feet very nicely. And once a properly timed flare is working correctly for you, you will be able to trial-and-error your timing to get it dialed in just right.
At some point before your flare, make a point of getting your BODY as upright as possible. “Getting upright” isn’t just moving our hands up and getting our legs down, sometimes we need a really focused movement to get our body as upright as we can, which makes both pulling in for speed and flaring easier.
Also, take a look at the adjustment of your leg loops. Some harness manufacturers like to use adjustable buckles on their leg loops that only hold a setting when under tension… which for a leg loop is only when launching or landing. These adjustable buckles have a tendency to work their way looser and looser over time, which means you are hanging lower and lower and your flare is less and less effective. To get proper leg-loop adjustment: When you are laying prone with your legs in the harness, the harness mains should attach to the harness just a little back (toward your feet) of your balance point, so that there is always a little bit of head-down force keeping you in the prone position. When you rock your body upright, you need just enough slack in the leg loops that your body sinks into the harness just enough that now the attachment point for the mains is in front of your body’s balance point, which means once upright your body stays upright even if you let go of the control frame. For those reading with back-plate race harnesses, it’s a slightly different your you because the back plate does not allow you to slide down into the harness- it will hit you in the back of the neck or head. This is why back-plate race harnesses have that slider mechanism, so that you can move the balance point of the harness to either keep you prone or keep you upright. In a race harness the leg loops can’t be too tight, but can’t be too loose either… it’s very tricky to get them just right.
Back to the pilot who wrote in! Focus on your approaches, check your gear is configured correctly, and then practice practice practice! I hope you don’t take this wrong, but as a H2- and especially one struggling with landings- if I were your instructor I would very much discourage traveling to new sites just yet. Pick one site that you can fly early morning or late-day smooth air sled rides, and land in a huge/soft/grassy LZ (like Ellenville or Lookout Mtn) and practice practice practice! You’ll have your whole life to travel to other sites and fly in thermals and whatever else… right now you need to survive long enough to get to that point. You need smooth conditions and a forgiving LZ… and lots of repetition!
One note on repetition- training hills are great for a lot of things… but not working on our approaches. Most training hills are not high enough or do not give us enough ground clearance to really pull in for speed so that we can do a proper round out and ground skim. Not saying it can’t be done, but it’s a difficult place to practice such a thing. Since your launches and flying look ok, and you have your wheels, sled rides in calm conditions is going to be your best means of practice.
Again I thank you for your bravery and selflessness in sharing your journey with all who read… and I hope that some of the things written here help you, and many others out there as well.
Merry Christmas and soft landings in 2014!