Takeoff Technique discussion
Preface
The topic of proper launch technique came up recently in the OZ report. It was discussed there over several editions of the report. At the same time, the topic was also discussed on the HG list (HangGliding@yahoogroups.com). This second discussion devolved into a back-and-forth between two people, with others chiming in at times. There is a lot of text here. I'd suggest you read through the OZ report submissions, then tackle the HG list msgs. Hopefully, by the time you're done, you'll be a bit confused, but you'll also have a few more ideas on how to adjust your own launch technique so it'll be the best it can be.OZ Report Discussion
(from the 10/11/02 OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n210.shtml)
3 ways to launch successfully
Pat Denevan missio@hang-gliding.com and Greg Shaw GflyS@aol.com send in their very knowledgeable article and illustrations about how we get off the hill:We can group launch techniques into one of three methods:
1) the "hold-it-down" style;
2) the "force-it-up" style;
3) the "let-it-float" style.
The main difference is the point where you shift from pushing the glider forward to pulling with the harness, ranging from before the run starts to the moment your feet leave the ground.
With the “hold-it-down” method, the control bar is braced against the shoulders, and the arms hold the downtubes back and the nose down to keep a low angle of attack:
This gives you a strong grip on the glider to resist strong winds and turbulence on launch, and can inspire confidence in turbulent air. The run accelerates down the hill, holding a low angle of attack, until the nose up bar pressure reaches the "flying point" when the glider's lift overcomes your ability to hold it on the ground, or allowing the nose to rise slightly pulls you into the air.
This is a technically simple launch; in fact, the easiest of the three methods to perform. It works very well when the launch is steep, or there is lots of wind.
On the downside, it is not good for crosswind or flat slope launch conditions. It is hard to set the best angle of attack since the grip on the control bar does not allow normal pitch feedback. Without the normal hang-from-the-harness, feedback-through-the-fingers arrangement of flying, angle of attack must be set visually without good reference.
This becomes an issue on a flat slope, when angle of attack must be optimized to develop flying lift in as few feet as possible. Balance is critical with this method. Since you are not flying until you leave the ground, it is necessary to muscle the wing against destabilizing forces. Leverage is limited during the run, so any roll inducing forces such as a crosswind may be beyond control if not anticipated before the run begins.
The “force-it-up” method starts with the glider lifted hard against the harness straps before the launch run begins:
Like the “hold-it-down” launch, this method is a simple 1-stage technique. The control frame is lifted with the arms until the harness straps are tight. When the wing is balanced, the run begins, pulling the glider along immediately with the harness. Angle of attack and roll control is maintained with normal flying control movements.
This launch has the benefit of a built-in "Hook-in Check" just before the run starts. It allows you to start pulling immediately with the harness for easier angle of attack control, and better sensitivity to glider feedback. Since the glider is loaded as early as possible, the pilot has maximum ability to control undesirable roll or drift.
But the method is tough on pilots with short arms or long control frames. It takes a lot of strength to hold the glider up in light winds, adding the burden of remembering to loosen the grip on the downtubes once the run begins. In strong, turbulent conditions, you are more exposed to upset before starting the run.
The “let-it-float” technique is a two-stage method, combining elements of the previous launches. The glider is balanced braced against the shoulders. The run begins after setting angle of attack, by pushing with the shoulders. As the glider generates lift, it is allowed to rise, sliding up through your fingers and across your shoulders, until the harness straps are tight and you transition to pulling the glider with the harness. At this point, angle of attack and roll is controlled through normal flying movements.
Proper angle of attack is sensed through glider feedback, made possible by the light touch on the downtubes. After the glider accelerates to flying speed, relax the bar and lift off.
This technique becomes the same as the “hold-it-up” method, once the glider has floated up tight against the harness straps during the run. With wind, the glider can be floated at the beginning of the run and is essentially the same technique, without the tight grip on the downtube that inhibits sensitivity.
The key benefit of this launch method is the ability to maintain a light touch throughout the launch for precise angle of attack control, quick response to unwanted roll, and the ability to sense the pressures that signal it's time to leave the ground. It is the best choice for light winds, crosswinds, or flat slopes.
On the negative side, it takes more skill and sensitivity to do well. That means you must invest some time in training and practice. Practice on a good training hill with steady light wind. Experiment letting the glider rise smoothly earlier and earlier, maintaining good angle of attack and path control. Better yet, work with an instructor. He or she has a series of exercises that will teach you the right skills in short order. Soon it will be some other pilot who always seems to get the "bad cycle" on launch.
(from the OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n211.shtml)
Arms akimbo - launching
Henry Bittner hbittner@responsedynamics.com writes:There is one detail I think you've got wrong (and in other articles on fundamentals of launch technique from Mission Soaring it has also been omitted). That thing is Pushing the Glider with the Arms before the glider is flying (first 3-8 steps usually).
The arms must stay in contact with the bar to provide a fulcrum before the glider is flying whether the strap is tight or not.
Try lifting the glider up to straps tight in no wind, and then drop your elbows so that it’s just your hands pulling up to hold up the whole glider. You can't do it, the tail will fall and your shoulders will slip through the control bar. (I bet you've seen students do this. They don't know to chicken wing out the elbows to get the arm in contact with the back of the d-tube.) You must chicken wing out your arms to support the lifted up glider, as you do this you are also providing a corrective pitching moment between you arm pushing forward and your hand pulling in.
Now certainly the tight hand strap helps as you know on a windy launch where your weight is forward on the strap helping to hold down the nose, you don't need your arm on the bar then, but then the glider is already flying! See that's the key. The glider has its own pitch stability then.
When the glider is not flying you need the arm there on the back side of the down tubes other wise the tail of the glider will fall and the hang strap will go loose even though you are still holding the d-tubes in your hand at the same "lifted-up" height. Now there may be some people that have very strong wrists that can to all the pitching moment with wrist action like Revo, but the rest of us need our arms on one side and hands on the other.
From my time on the T-hill I have come to learn that this is actually a major key to the first 3-8 steps of most launch runs. When a new student has a hard time launching, or an advance pilot has trouble with popping the nose, or has no feel, it is often because they drop their elbows too soon before the glider is flying and the hang strap is tight, really tight.
Tell an advance pilot who was having some bad looking launches to keep the arms in contact with the bar until the feet are pulled off the ground and they usually do much better. Look at some launching video and you'll see the good pilots with elbows-a-kimbo as they run until the glider is flying. Look at some video of some bad launches where the pilot is putting in lots of effort trying to run but they just seem to get off slow and turned. You'll see they dropped their elbows too soon taking the arm out of contact with the d-tube.
I see you say ..."The control frame is lifted with the arms…." Yes you’re right. That's quite right, but the run does not begin immediately with pulling from the harness as you say. It begins immediately with pushing with the arms, then pulling with the harness.
All I'm saying is, in the future we should all emphasize the pushing with the arms part, because as they say the devil is in the details. Lots of folks may think the tight hang strap in no wind is all they need. It’s not. They take one step with the strap tight, no wind, with out the glider flying, and the glider will rotate back, pitch nose up, and drop behind them since the hands are way forward of the center of gravity of the glider. At this time they may catch the glider’s control frame with the arm, but it’s too late. A little loss of pitch has happened, giving a little turn, or slowing them down.
By the way Pat, Greg, Don Burns, and Dave Yount of Mission Soaring Center have done so much to advance the art of teaching HG. I've been to three of the MSS ICPs and enthusiasm and energy for teaching technique is really high and Pat’s ICP is great fun for those who really enjoy T-hill teaching.
Keep them elbows out pushing the glider, look ahead, watch and feel your launch happen.
(from the OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n211.shtml)
Launching – hold it down
Ben/Alegra Davidson, Tek Flight Products tek@snet.net writes:We have been teaching the "Hold it down, drive w/ shoulders/upper arms, use hands for pitch and roll control only" launch for at least 20 of our 25+ years of teaching and to the best of our knowledge, only three of our graduates have ever blown launches --- ever.
The crosswind and shallow launches are not an issue if the pilot also learns to be light on grip and stay controlling to a distant point. In fact, it becomes the most bullet proof shallow slope launch technique as it is easier to gain more speed with less muscle.
We have sort of quantified the greater efficiency of the "hold it down" method on a shallow slope by noting the distance that a pilot will fly having launched with that method as opposed to a "pull with harness straps" method. Building speed with the glider held down and at about the neutral angle of attack is significantly easier and happens more quickly.
The instructions to the student/pilot for launch run and launch are "As you approach your peak speed, let the control bar out to about trim, run the glider into the air and as you pedal air, bring the bar back in a bit to insure safe airspeed".
Pre H-1 pilots are taught crosswind launches on shallow slope and have no problem as long as the infamous "focus" is good. Key to all this is focus and light grip. Even new pilots seem to be able to adjust to gliders with different pitch feedback if warned to not let glider launch early and if they have shown good launch run, to "ease the bar out" if their run is maxed out and the glider doesn't want to launch.
I'll open another can of worms: the bullet proof landing.
Most gliders can be trimmed at about min. sink speed so that you can have a guaranteed good landing if you flare at landing altitude from trim. There are a few exceptions, but most of the gliders that I have flown that were manufactured in the last 10 years could be trimmed for this.
On virtually all Wills Wing gliders in that time period (the HPAT was an exception) it would be if trim speed is set where the tufts are walked out 45 to 90 degrees with the pilot prone.
(from the OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n212.shtml)
Launching – the sweet spot
Ben/Alegra Davidson, Tek Flight Products tek@snet.net writes:The infamous "nose popping up" is usually cured if the pilot has the glider supported on the "sweet spot" of upper arms/shoulders, where the glider is comfortable and hands need do nothing but control pitch and roll. The pilot needs to be sure to start with one foot in front of the other.
It can take quite some time and work for some pilots to find that magic spot and to have gliders go there automatically every time they pick one up, but the time spent teaching them to support the glider there ultimately helps generate that bulletproof launch.
(from the OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n212.shtml)
Chicken wings - launching
Rudy.Stephen.R Stephen.Rudy@IGT.com writes:I am surprised at the various training schools promoting launch techniques that focus on floating off the hill at very slow speeds. Statements about 'optimizing the angle of attack' to lift off the hill as soon as possible (versus with plenty of flying speed) seem to me methods sure to result in launch mishaps. Ben/Alegra Davidson's response matches far better with what I believe ensures success in launching:
1- holding the control bar with enough authority to control the angle of attack,
2- keeping the angle of attack close to neutral and accelerating rapidly to your maximum running speed,
3- allowing the angle of attack to increase to near trim speed,
4- pulling back in some on the control bar immediately after take-off to provide some extra airspeed for safety.
Pat Denevan's illustrations on launch technique all show the pilot gripping the bar from behind. I believe the chicken wing discussion about using the upper arm to push the control bar also assumes this grip from behind. I see more and more pilots using that kind of grip and I don't understand why the flight schools are teaching it.
Setting the downtubes across the deltoid muscles, wrapping your upper arms behind and around them, so that your forearms and hands come around to the front of the downtubes provides very solid control over the glider when launching. My grip has my fingers behind the downtube and my thumb hooked from the outside and around the front of the tube. This allows me to feel gusts/crosswind/pitch input immediately and I have a solid connection for controlling that input. My guess is that many flight schools reject this grip because there is more of a transition required as the glider starts flying. You must unwrap your arms from the downtubes and grip either the downtubes or basetube from behind.
Avoiding the difficulty of learning that transition between the wrap around grip for launching and the flying grip is poor preparation for students that will eventually be taking off in less than ideal conditions. I feel completely confident launching in turbulent and windy conditions that would terrify me if I had nothing but my hands and the tenuous connection of my shoulders and/or hang strap for controlling the glider
From: erniecamacho
To: oz_report@yahoogroups.com
Sent: Tuesday, October 15, 2002 8:00 AM
Subject: re: chicken wings - launching
I agree completely with what Steve Rudy describes as the best launch technique in the latest OZ report.He says in part: "Setting the downtubes across the deltoid muscles, wrapping your upper arms behind and around them, so that your forearms and hands come around to the front of the downtubes provides very solid control over the glider when launching."
I'm not quite sure where my deltoid muscles are. Others may not either. I explain it this way: I want the control bar to be a solid part of me as I start my run. When I pick up my glider, I wedge my shoulders inside the downtubes with my shoulder joints just in front of the downtubes and the downtubes resting on the big muscle going down the back of my arms (is that the deltoid?). My arms are wrapped around the uprights the way Steve describes so that the inside of my elbows are touching the downtubes, my fingers are on the outside of the downtubes and pointing down. My hands are pulling down to keep the downtubes firmly wedged on the outside of my arms. The effect is to have the downtubes feel like they're part of my arms. As Steve went on to describe it, this position gives me excellent control, and the transition of my hands to flying position as I run happens naturally and smoothly. Again I agree with Steve that the illustrations accompanying Pat Denevan's article were completely alien to me. They just looked way too tenuous, as well as hard to hold for any length of time. With my shoulders wedged inside the control frame, I could hold up my glider for a long time, if need be.
That brings up more point. I've seen lots of pilots pick up their gliders and then the longer they hold them, the shakier they become, and the less confident they appear, as they fight to keep the wings level. I always leave the glider on the ground until I'm sure the launch conditions are optimal, then I pick it up, square it away, and run. The less time you hold the wing up, the less time the wing has to wear you out as you try to maintain wings-level. You don't want to be too hasty either. As in all things, there's a balance.
One final comment: I agree with Pat's description of the three launch styles, with the 3rd being the best. Having said that, I agree once again with Steve that a bias toward nose down at the start of the run is prudent. I know of several advanced pilots who always pop their nose up a bit, unconsciously, and then have a less-than-optimal run.
Ernie Camacho
(from the OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n213.shtml)
You can't please everyone - launching
Wesley Hill wesleyianhill@yahoo.com.au writes:I continue to be amazed at the number of articles you get which incorrectly describe how to launch a hang glider.
Stephen Rudy (Oz Report, v6, #212) comes close to getting right, but fails to note that a hang glider is controlled by weight shift. This is true even during the take-off run, as the pilot should be applying weight through their hands to control the pitch and roll.
I agree with Rudy that most of the other submissions you have received have seriously flawed techniques.
(editor's note: I'm just happy to see that I've received more responses to Pat's original launch article than I received about the cracking skin articles. J )
(from the OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n213.shtml)
We're humble here in South Africa- launching
www.hanggliding.co.zawww.hangglidingschool.com
Johan Anderson intense@iafrica.com writes:
I have been following the thread on launch techniques with interest in the last few Oz Reports. We always feel very humble when it comes to reading and taking advice from pilots on the cutting edge of hang gliding development and training such as those in the US. But perhaps our ideas of training techniques are pretty great after all. (I just cannot believe some of the things I have read! Guys are teaching those techniques!?)
Anyways, I cannot help but agree with Rudy Stephen on his technique advocated except about the difficulty to "unwrap" your arms from being wrapped around the D tube. I teach my students this from day one and nothing is more natural to my mind.
Ben Davidson is correct in keeping the glider on the shoulders (sweet spot) to prevent popping the nose. This seems to be the most common problem for pilots when having difficulty in launching. (Trying to force/get the straps tight too early in the launch run).
Anyways, before writing a whole book on launching, my point is that when holding a glider on your shoulders with arms wrapped around the outside of the D-tubes in a sword grip, (by far the most sturdy holding technique), there is no need to "unwrap" your arms during the run. After some 2-4 steps as the glider starts to lift simply allow your elbows to bend allowing your upper arms to "push" on the D-tubes while maintaining a "sword" grip. (Dont move your hands, just bend at the elbows.)Soon your straps are tight and you are still in "sword" grip accelerating to top speed.
The advantage of having a "sword" grip is that it ensures the pilot stays inside or through the A-frame during the launch. (i.e. leaning forward) changing your grip to "pistol" grip too soon often allows the nose to pop. Once near TO speed, swivel the hands one at a time to pistol grip, i.e. don't let go, by simply keeping your thumb around the front of the D-tube while straightening your fingers and sliding them to the front of the D-tube while rotating your palm backwards. (Sounds complicated but it is very simple and you can practice this grip change while standing on one knee behind the A-frame while the glider is resting on the ground.)
At this point in time ease the bar forward for lift off. (As soon as you're off the ground gently come back in a bit on the A-frame to get that extra speed in order to clear the hill safely.) "Unwrapping" did not need to be done - it just happened naturally.
(from the OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n213.shtml)
Grapevine Grip - launching
Ben Davidson tek@snet.net writes:About five years ago, I thought that I had the perfect answer to getting new pilots to use the "grapevine" grip for launching. It would also insure that they be light gripped. I was going to revolutionize basic training. No longer would anybody have to teach a whimsical launch. "Light grip" once in the air would be a given. All that had to be taught was use grapevine grip for best control during run, and as you approach peak speed, simply release the downtube with the thumb and finger or two that are in front of the control bar.
The pilot could stay that way and even though the flare would be done with the downtube pushing against one finger, they could flare and land. They would be able to use the fingers that were now to the side of the downtube for roll control and curve them a little to pull in.
I'd do demos launching, flying, landing. Actually, for every student I do a demo using that method. I have only been able to get maybe five first day pilots to launch that way. In five years.
(from the OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n213.shtml)
Nose popping - launching
hangpoints@btinternet.com writes:Pilots who are nervous about their light wind takeoffs are often totally psyched up for the launch. They know they want to run very fast, and they know they didn't last time! This often leads to a sudden "sprint" start with the pilot eager to get going really fast. Unfortunately, the pilot thus sets off suddenly and leaves the glider behind causing the nose to rotate up and the glider to lift the pilot too early or create loads of drag holding the pilot back.
I managed to coach a few pilots to stop this be encouraging a gradual acceleration. Walk the first pace and then accelerate, so they can keep the glider going with them (also holding it the right way too). This also seems to help the pilot relax a little and so stay aware of the glider attitude, and enables them to abort if things are going wrong at an early stage (when it's not too steep).
The problem women have is the control frame is too tall. With their shoulders in the right place to get the glider moving the base bar is too near the ground. However fitting a smaller control frame makes the glider handling worse so it is no simple matter for the glider designers. It's better to narrow the base bar and leave the downtubes the same length (new side wires).
Critics of female pilots' launches are usually ignorant of these problems - people look at Kari and say, well she can launch OK - but she is taller than a lot of men. Lots of women have successful launches despite problems with base bar clearance. Kathleen's launches are no problem but the base bar near the ground means she needs time before it feels good enough as the margin for error is very small
(from the OZ report: http://www.davisstraub.com/OZ/index.php?Ozv6n214.shtml)
The Inside Grip - launching
Russ Brown inside_grip@yahoo.com writes:Sorry, but the Oz Report can't expect to fling around terms like "grapevine grip", "pistol grip" and "sword grip" without someone mentioning the Inside Grip. That'd be like taking a course in Comparative Religions and studying Christianity and Islam, but then leaving out that one in Laos where they worship monkeys.
Now I don't expect to persuade any outside grippers to burn their Bibles, but I do believe the Inside Grip has a place in a pilot's bag of tricks.
When launching a hang glider, there are a variety of factors to consider, most importantly the strength of the wind and the steepness of the launch. Other more subtle factors are the length of a pilot's legs, the width of their shoulders, the strength of their hands, and the static balance of their glider. On a given day, all these factors flow into specific needs for foot speed and angle of attack. Most people don't even consider that a change in grip style can help them run better or more effectively control their glider's weight.
This is the Inside Grip:
Others have mentioned the importance of creating a solid fulcrum point in order to dynamically adjust AOA. The inside grip accomplishes this with the hands and elbows. Why is this admittedly painful configuration better than an outside grip?
With the outside grip, you wrap your arms around the outside of the downtubes, which necessitates grabbing higher on a more narrow part of the A-frame. However, with the Inside Grip, with your elbows inside the control frame, you can grasp lower on the downtubes which brings the basetube up and out of the weeds. Getting the basetube higher (and also more out in front of you) allows you to pump your knees higher in no-wind launch scenarios.
Just like the outside grip, you're lifting the entire glider with your hands, but it ends up being easier because you are sort of "wedged" inside of the control frame -- instead of having that distracting feeling that your downtubes are slipping down and away. This is a godsend for smaller pilots.
On your run you can totally focus on elbow-actuated AOA adjustments and unlike the outside grip, these adjustments have a more independent feel. It's sort of like running with a full glass of water without spilling it - with the Inside Grip you are holding the glass at comfortable distance from your body but with the outside grip the glass of water is pressed up against your body and there is more spillage.
Students get a side benefit from the Inside Grip because if they blow launch, they'll just swing harmlessly through the A-frame. If you blow launch with an outside grip you run the risk of shoulder or elbow injury.
But there's one situation where the Inside Grip really shines -- the high wind cliff launch. In high winds everything happens faster. When a wing stalls here, it stalls fast. That's why you need a grip on the downtubes that allows you to pull in instantly and even allow you to move your whole body through the A-frame without moving your hand position. The scariest windy cliff launch you'll ever see is someone desperately trying to pull their body through the inside of their control frame while using an outside grip.
Can you see that the Inside Grip might have a few advantages? Try it once someday when nobody is looking :-)
Date: Thu, 17 Oct 2002 10:07:33 -0700
From: "Levine, Barry"
Subject: re: Inside Grip
While the Inside Grip is an interesting tool to add to the bag of tricks, there is one statement in the description that I cannot let stand. Russ writes, in part:>Just like the outside grip, you're lifting the entire glider with your hands, but it ends up being easier because you are sort of
>"wedged" inside of the control frame -- instead of having that distracting feeling that your downtubes are slipping down and
>away. This is a godsend for smaller pilots.
If one is using the grapevine grip as it was taught to me, the weight of the glider rests passively on the deltoids, and the hands are lifting nothing. This way the hands are relaxed, and make inputs only in the roll and pitch axes, without carrying any of the weight of the glider.
Barry
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HG List Discussion
Date: Mon, 14 Oct 2002 23:52:07 EDTFrom: flymedave@aol.com
To: HangGlide@yahoogroups.com
Subject: Launching ,launching, launching
I've read all the recent launch techniques in the OZ and the reply's and none of them covers the method I learned, teach and use. I amazed at all the stuff and reasons for the stuff that people dream up. I know this sounds strong..But they make something simple unnecessarily complicated and dangerous at different situations..Shessh! launching is easy and easy to teach.. Just set the glider on your shoulders ..Bottle grip,, set the angle of attack positive > for the amount of wind and slope..start our run> Push forward with the shoulders to break the gliders inertia to get the wing moving ... Let the wing float up tight on the hang straps.. This mayand should happen quickly ( second or third step more or less depending on wind and slope ) ..Now as soon as the wing becomes tight on the straps you concentrate on flying the glider through the DTs..Lean into the run and add power.. We accelerate we pull in smoothly and leave the ground at our choosing or are pulled off the ground by the lift being generated by the wing..
The object here is to get the wing flying and fly it through the launch tow the wing along with through the harness straps.. This gives us control of all three axis quickly.. This is not complicated ,but does require practice,but duh ! thats what training is for and thats what you should feel in every launch.. We should recognize every step of the launch and how well we executed it and be able to look back and know how well it all went..
NOT GOOD> Holding the wing down method will bite you because you are not flying the wing almost until lift off and a dropping wing will go to the ground before you can react to it ..Holding the wing down with your arms wrapped around the bar is really dumb in light wind and turbulent situations .. Letting the wing float up tight on the straps works fine in moderate glassoff and coastal winds,, but is just plain dumb in strong gusty thermal conditions on a cliff or ramp and pushing the glider up tight in no wind is foolish at best..
pilots should learn to read a launch and practice different launch methods for different condition,sites . all involve getting the glider flying quickly and controling launch by flying the glider through the launch..
DaveH
Date: Tue, 15 Oct 2002 10:19:38 -0700
From: "DavidRSw"
To: HangGlide@yahoogroups.com
Subject: Re: Launching ,launching, launching
Hi Dave,You said:
> Just set the glider on your shoulders ..Bottle grip,, set the angle
> of attack positive > for the amount of wind and slope..start our run>
> Push forward with the shoulders to break the gliders inertia to get the
> wing moving ... Let the wing float up tight on the hang straps.. This may
> and should happen quickly ( second or third step more or less
> depending on wind and slope ) ..Now as soon as the wing becomes
> tight on the straps you concentrate on flying the glider through the
> DTs..Lean into the run and add power.. We accelerate we pull in
> smoothly and leave the ground at our choosing or are pulled off the
> ground by the lift being generated by the wing..
As we have discussed before and you still won't accept, as soon as the hang strap becomes tight, you lose power to accelerate when compared to the use of the arm/shoulder. To prove this once again, look at the direction that the hang strap is pulling. It represents a force vector. It is not pulling forward; it is pulling *down* and only a *little* forward. If pulling with the hang strap is so effective, as you seem to think, why don't you "break the glider's inertia to get the wing moving" with the hang strap too?
Thanks,
Dave Swanson
Glendale, CA
Date: Tue, 15 Oct 2002 22:47:11 EDT
From: flymedave@aol.com
To: HangGlide@yahoogroups.com
Subject: Re: Launching ,launching, launching
In a message dated 10/15/2002 1:32:46 PM Eastern Daylight Time, DavidRSw@msn.com writes:> As we have discussed before and you still won't accept, as soon as the hang
> strap becomes tight, you loose power to accelerate when compared to the use
> of the arm/shoulder. To prove this once again, look at the direction that
> the hang strap is pulling. It represents a force vector. It is not
> pulling
> forward; it is pulling *down* and only a *little* forward.
> If pulling with the hang strap is so effective, as you seem to think, why
> don't you "break the glider's inertia to get the wing moving" with the hang
> strap too?
> Thanks,
> Dave Swanson
> Glendale, CA
>
Towing the glider through the Hang strap is standard proceedure.. It works great .. by imparting our energy into the glider when using the correct AOA we allow the wing to create lift.. The vector forces of the wing are forward and this makes the wing go fast but lift at the same time.. This is felt as a building pitch pressure in the DTs.. The glider wants to pull you off the ground but you just pullin a little more and kick the ground a few more times to get lots of air speed and lift before leaving the ground ..
I did A good demonstration of this at Hadleys butte,Summer lake OR. Hadleys is a FSL to start with .. The wind that day was cross from the left and 10 or better at times .. To the left it was abit steeper but with big boulders after the first couple steps..Looked terrible but it was a breeze(10 or better )to dance down over the boulders and just kick off the top of the rocks as the glider was carrying most of my weight .. No one else thought it easy or doable.. Its called Moon walking ,Its what you have student practice on the training hill ..Get most of your weight into the glider and just power it along controling pitch ..
Its all about pitch control and powering the wing ...It is the most technically correct method to launch 95% of the time..
An other truth of pitch control is that a wing can always fly faster then you can run.. If we hold the nose too low its easy for the wing to get a head of us and pull down more and we do a face plant and that hurts >Ask Frank..
Another truth is that a wing will lift its own weight at a much slower speed then it will lift us off.. so in light Flat Slope conditions we add a couple of degrees to the pitch to help get the wing off our quickly shoulders and the straps tight..Add the power and speed happens.. Practice it and you will see the beauty of it .. Just like students practice on a FS training hill.. The sequence of events stays the same through all types of wind and sites weather it's Light FSL or a windy cliff..
DaveH
From: "DavidRSw"
Date: Wed Oct 16, 2002 6:32 pm
Subject: Re: [HG] Launching ,launching, launching
Hi Dave,> Towing the glider through the Hang strap is standard proceedure.. It
> works great ..
Not so standard according to recent posters in the Oz Report.
> The vector forces of the wing are forward and this makes the wing go
> fast but lift at the same time..
Negative!! The vector of pull is in the direction of the hang strap. The direction of the hang strap is only a little forward and predominantly down toward the ground. That's not the direction needed to accelerate the glider on a fsl.
> Its called Moon walking ,Its what you have student practice
> on the training hill ..Get most of your weight into the glider and just
> power it along controling pitch ..
But Dave, I don't have to power AGAINST the drag of the glider if the hang strap is loose! If the glider won't carry YOUR weight at some air speed, then the wing is stalled, pure and simple. Why would you consider it a good idea to launch with an intentionally stalled wing?
> Its all about pitch control and powering the wing ...
The acceleration power is applied directly to the upper downtubes with the shoulders in *exactly* the direction that the glider is accelerating, i.e. FORWARD
> An other truth of pitch control is that a wing can always fly faster
> then you can run.. If we hold the nose too low its easy for the wing to
get > a head of us and pull down more and we do a face plant and that hurts
That's not true if we take larger strides as the glider accelerates. Hey Aaron, has a glider ever gotten ahead of you during a launch? Me neither.
> Another truth is that a wing will lift its own weight at a much slower
> speed then it will lift us off.. so in light Flat Slope conditions we add a
> couple of degrees to the pitch to help get the wing off our quickly
> shoulders and the straps tight..
The first sentence is true, however, you are not flying just the glider. You MUST fly you AND the glider. Acceleration to the speed that supports both you AND the glider is the point of the whole launch sequence. This is done easier by pushing the glilder with the shoulders on the downtubes and positioning the glilder at a low aoa (like max glide aoa). Forget the old "fill the sail with air" crap. The instant that I have to run or pull the glider by the hang strap with the aoa allowing the glider to carry its own weight, is the instant that I have to run or pull against the DRAG of the glider. If I have to run against the drag of the glider, my acceleration to flying speed (both pilot and the glider) will ALWAYS be slower. Eliminate the drag of the glider by keeping the aoa lower. It's that simple. I'm sure that you have heard the phrase "they mushed it off the hill". One can only mush if the glider is stalled and not carrying the weight of the glider and pilot. Have you ever seen a glider mush during a launch without the hang strap tight?
Thanks,
Dave Swanson
Glendale, CA
From: DH
Date: Wed Oct 16, 2002 7:35 pm Subject: Re: [HG] Launching ,launching, launching > If the glider won't carry YOUR weight at some air speed,
> then the wing is stalled, pure and simple.
Dave, surely you know that's not true. Stall relates to angle of attack. If the airflow isn't separated, it's not stalled.
> The instant that I have to run or pull the
> glider by the hang strap with the aoa allowing the glider to carry its own
> weight, is the instant that I have to run or pull against the DRAG of the
> glider.
Can a husky run faster towing the sled or carrying it? :-).
Fly the glider through the launch run. Carrying the damn thing as a dead weight is way too much work to interest me. Don't believe it? Pick up a 4x12 about 20' long and try to run down a hill with it.
Dennis
Date: Thu, 17 Oct 2002 09:57:01 -0700
From: "DavidRSw"
Subject: Re: Launching ,launching, launching
Hi Dennis,> > The instant that I have to run or pull the
> > glider by the hang strap with the aoa allowing the glider to carry its
> > own weight, is the instant that I have to run or pull against the DRAG
> > of the glider.
>
> Can a husky run faster towing the sled or carrying it? :-).
Can a football lineman pull a practice sled faster than he can push it? Can a football lineman pull or push a lighter sled faster? The drag of additional lift from the tight hang strap at the start of the walk, jog, run, must be overcome by the pilot. Why waste that energy? Use the leg muscle strength to accelerate the glider instead of against the drag. Remember that the direction that the hang strap is being pulled, is the direction that the pilot is pulling it. If the hang strap isn't pulling straight forward, then the pilot isn't doing an effecient job of pulling the glider into the air. Can you climb faster with an aero tow or a truck tow? Acceleration of airspeed is forward, not mostly down.
> Fly the glider through the launch run. Carrying the damn thing as a dead
> weight is way too much work to interest me.
I know where my grey hair is coming from, it's leaking out of my brain and into my hair. I fly hang gliders to keep in shape. If I can't pick up a glider, then I do need to stay in my easy chair. Or maybe I should just fly sailplanes.
> Don't believe it? Pick up a
> 4x12 about 20' long and try to run down a hill with it.
Notice I said low aoa. As I increase my run speed, and thus air speed of the wing, it will start to progressively carry a little of its own weight. The glider carrying its own weight occurs later in the loose hang strap run than in the tight hang strap version, that's all. Now try running holding that 4x12 with the 12x20 perpendicular to the direction of travel, with the largest surface area against the wind. Don't you just love all that drag? Well, it's not necessary. Now you have the understanding to solve the problem.
In the very beginning of the walk, jog, run, long strides, air strides, I'm carrying all the weight of the glider while holding the glider at some low aoa that doesn't lift all the weight of the wing off my hands or shoulders (as your launch position dictates). Maybe it might take only 10 lbs. off me. As I walk, jog, run, long strides, I build airspeed across the wing and it begins to develop lift progressive more until it not only carries its own weight, but mine too. All the while I haven't increased the aoa into the higher aoa range where the drag is higher too. I keep the aoa in the range of the low drag portion of the "drag bucket". I can feel this in my hands, shoulders, and hang strap as the launch progresses. With a tight hang strap from the very beginning I can't tell if the wing is stalled, on the edge of stalling, or low drag. During this walk to jog phase with the hang strap tight, the wing is making more lift and consequently has higher drag than with the lower aoa. Thus I have to fight against this drag of the higher aoa. But I don't have to, if I lower the aoa to a point that I can accelerate faster and progress to higher airspeeds faster. Thus narrowing the window where my airspeed won't sustain the weight of glider&pilot. Here's how it works out: would you prefer to have a tight hang strap at 3 mph airspeed or 13 mph airspeed? There's going to be a tight hang strap at some point. If I'm a good pilot, I can make the glider progressively carry its own weight and NOT have it make the hang strap come tight! I fly the glider down the FSL. This is low drag acceleration of the glider. What I'm doing is flying the glider down the launch FSL without a tight hang strap so that I'm not fighting against the glider's high aoa drag. I'm able to accelerate my body just fine too, almost as if I was attempting a launch unhooked.
And finally, because I'm able to keep more of my own body's weight on my feet (no tight hang strap taking weight off my feet), I'm able to put more force into my run. Consequently, more force into my shoulders to push the downtubes into a forward faster acceleration. Now doesn't that seem safer?
Thanks,
Dave Swanson
Glendale, CA
Date: Thu, 17 Oct 2002 12:33:32 -0700
From: DH
Subject: Re: Launching ,launching, launching
> As I walk, jog, run, long strides, I build airspeed across the wing and> it begins to develop lift progressive more until it not only carries its own
> weight, but mine too. All the while I haven't increased the aoa into the
> higher aoa range where the drag is higher too.
So where's the argument? Isn't that how everybody does it? Nobody EXCEPT YOU said anything about holding the glider above the approx. angle of attack for best L/D. The whole hang strap thing is a distraction from the discussion at hand. It's irrelevant. Nobody is using the glider as an airbrake while he runs. Strap tight, strap loose, whatever. The glider is held near its min drag AoA.
Dennis
Date: Thu, 17 Oct 2002 14:02:14 -0700
From: "DavidRSw"
Subject: Re: Launching ,launching, launching
Hi Dennis,Thanks for letting me take another opportunity to clarify some minor details. It would appear that you haven't noticed that the immediately tight hang strap aoa is NOT best L/D aoa. A tight hang strap before the beginning of the walk, jog, etc, is much more prone to having too high of an aoa, thus it does act as an airbrake. I'm glad that you agree that a low aoa is the best way to launch.
Thanks,
Dave Swanson
Glendale, CA
Date: Thu, 17 Oct 2002 22:52:00 EDT
From: flymedave@aol.com
Subject: Re: Launching ,launching, launching
In a message dated 10/17/2002 1:55:18 PM Eastern Daylight Time, DavidRSw@msn.com writes:> And finally, because I'm able to keep more of my own body's weight on my
> feet (no tight hang strap taking weight off my feet), I'm able to put more
> force into my run. Consequently, more force into my shoulders to push the
> downtubes into a forward faster acceleration.
> Now doesn't that seem safer?
> Thanks,
> Dave Swanson
> Glendale, CA
>
No it doesn't seem safe ..Hg gliders are weight shift control and all that takes place around the Hang( trim)postion ..During the whole launch sequence you have no real roll control and your not flying the glider your just charging off the hill and hope to hell the thing flys when you get to the end of where ever your going..Luckly most sites round off and you will get in to the air on shear speed along ..You rely on shear mucle to hold the wing level ... Plus the wings are much closer to the ground because you are holding it on or close to your shoulders..If a wing drops you have to inertia it back level .. You are not a flying package.. you are separate ,disconnected from the wing ..Flying the wing by the DTs works to a degree but I wouldn't teach that way.. I've flown trainers off 30' hills just hanging on the DTs..
The argument about not being able to get good speed by towing the glider doesn't hold air.. I can moon walk a wing down a hill at 30 plus MPH .. Any where from the second to fourth step the straps are tight and I'm flying the glider with the control bar .. feeling the pitch, roll ,yaw just as in the air..The ground is just something to kick at and add power to the flying package..
Honestly ,,I did not dream up this techneque.. I learned it in Instructor cert .. From Greg DeWolf ,, 1988.. I used the method you describ for 10 yrs I was self taught and it is fine for bailing off most launches .. But with a little practice I realized I had much more feed back ,,more controled and genrally safer launches..
It was all foreign to me in the beginning .. He explained the technical reason for each action and they are all correct and work in all launch situation..you have to make some leeway for body type, but for the most part its about power with the legs and flying the wing with the DTs.. The sooner the better..
This big worry of poping the nose is bull.. if you pop the nose its because your not paying attention to flying the glider..Once you get the wing flying its own weight and the straps tight its just pitch ,and roll control and powering the wing off the hill..
To me this is a very safe launch .. From Light FSL to windy cliff the feed back is the same ,, push with the shoulders, hold the pitch steady , let the wing rise tight on the straps as you lean into the run.. This is where it get complicated for some ... You have to be feeling the pitch , roll while powering the wing.. Of course the payoff is that you are flying the wing and if a wing drops you shift weight , if you hit lift you pull in..Nose down pushout .. Students learn and understand on the trainng hill and just get better as they advance..
Im not talking about poping the nose the get the straps tight.. Set the AOA so the glider will lift as the run is started ... You can hold the wing down to get more inertia going in higher winds.. Sure you feel to drag of the wing ,but its not something that will hold you back.. That weight in the hang strap is a good thing ,, Its feed back its telling you how much lift the wing is generating .. you feel it in your hips and you feel it in the DTs.. These are you instruments.. your legs are just the kickers..You have a light grip on the Dts and are sensing the wings levelness and pitch and reacting quickly to the feed back .. Its what we learn on the training hill..
Think back >>>>>>>>>>many >>>>>>>>>>years........... There we where ...On the training hill.......... Holding the glider,, hook in , wings level , pitch set postive enough for the straight in ,5 mph breeze to fill the sail ... We start slow ,push forward ,, the wing lifts tight on the hang straps and we run hard down the slope .. the wing is lifting most of our weight, but the slope is not steep enough to get airborne, so we just keep powering the wing along,, working the pitch and roll ,, even doing slight turns... happy that we are almost off the ground and the instructor says .. 10 more of these and you can go 10 more feet up the hill and maybe get your feet off the ground
..................................Fast ............................................forward.....10 yrs. >>>>>>Your standing on the flatslope of Gunter, 8000' asl in the owens valley >> the switchy wind straightens is 10 mph stactic.. You set the pitch ,,Start your run ,,You let the glider rise to straps tight in the third stride>>> Pour on the power >> 7th stride the glider is carring your weight and you could lift off ,but no way... You pull the bar in keep your feet on the ground and get three more powerful strides before the wing pulls you off at 30 plus mph airspeed.. you let the bar out to gain some altitude, fly out and turn right and start looking for that ride to 17k..
Glad that instructor guy was a hardass :-)
DaveH
Date: Thu, 17 Oct 2002 23:28:11 EDT
From: flymedave@aol.com
Subject: Re: Launching ,launching, launching
In a message dated 10/17/2002 3:34:22 PM Eastern Daylight Time, catapult@crestviewcable.com writes:> So where's the argument? Isn't that how everybody does it? Nobody EXCEPT
> YOU said anything about holding the glider above the approx. angle of
> attack for best L/D. The whole hang strap thing is a distraction from
> the discussion at hand. It's irrelevant. Nobody is using the glider as
> an airbrake while he runs. Strap tight, strap loose, whatever. The
> glider is held near its min drag AoA.
>
> --
> Dennis
>
True ..The technique I describe uses a >starting best glide AOA and pulling in through most of the launch ,, you genrally have so much speed at the end of the launch you can let the bar out to convert to altitude if needed ..
I guess it all about what gives you better feed back and control during the launch cycle...The worst thing I can imagine is a wing dropping with no way to shift weight to bring them level or at least hold it steady until I get off.. This droping wing or nose has been the cause of several launch crashes I ve seen and heard about ..
Having the straps tight is the crux of the matter.. In a flex wing > With a Ridged you slop the control bar around and you get spoilers..
Last year I had a sprog problem.. It would manifest it self just as the wing loaded up foot launching .. One launch was seriously crooked at whitecap... The right wing droped like a rock ,or left rose and I was in a 70 degree turn ,steep bank .. wing inches off the ledge..I instantly climbed on the left tube , pulled in and flew the thing out of it bank away only to dive at the top of the Oaks .. Had just enough speed to pop over the Oaks to sink like a stone into a fresh clearcut..
An other hard right turn at waldo and I knew I had a problem.. Fixed the sprog and all was well .. First I had heard of such a problem,, Some how one unscrewed ,but then I heard that a contestent in a SG contest wanged off the ramp side ways because of a sprog ajustment.. I look real close at them suckers now ..
DaveH
Date: Fri, 18 Oct 2002 14:53:05 -0400
From: "David C. Barnhart II"
Subject: Re: Launching ,launching, launching
flymedave@aol.com writes:Subject: Re: Launching ,launching, launching
>In a message dated 10/17/2002 1:55:18 PM Eastern Daylight Time,
>DavidRSw@msn.com writes:
>> And finally, because I'm able to keep more of my own body's weight on my
>> feet (no tight hang strap taking weight off my feet), I'm able to put more
>> force into my run. Consequently, more force into my shoulders to push the
>> downtubes into a forward faster acceleration.
>> Now doesn't that seem safer?
> No it doesn't seem safe ..Hg gliders are weight shift control and all
>that takes place around the Hang( trim)postion ..During the whole launch
>sequence you have no real roll control and your not flying the glider your
>just charging off the hill and hope to hell the thing flys when you get to
>the end of where ever your going..Luckly most sites round off and you will
>get in to the air on shear speed along ..You rely on shear mucle to hold the
>wing level ... Plus the wings are much closer to the ground because you are
>holding it on or close to your shoulders..If a wing drops you have to inertia
>it back level .. You are not a flying package.. you are separate
>,disconnected from the wing ..
For the benefit of those of us who are not normally foot launchers, maybe you should make it clear how these launch methods really apply. It sounds like all the argument is over hill or FSL launches, in contrast with cliff or mountain launches.
Most of the launches I've had the chance to use are of the type where you are off in 2 or 3 steps. What you are describing here, especially later, talking about 7th stride and so on, is much different. Unless there is significant wind coming in, it would be difficult on a cliff launch to hold the hangstraps tight in any case, and it seems like the DavidRSw type of launch would be the way to go. You never get to the moon-walk phase, and it seems to me that trying to hold the hangstraps tight and get the AOA correct would be more difficult than keeping the correct AOA from your shoulders.
My lack of ability to experience such launches is probably the reason I don't even possess the FSL signoff. I never fly anywhere I could actually use it. Are many of the western launches of the FSL or hill type rather than the "only room for 2 or 3 steps" type? Also, does anyone use the hangstraps tight launch for cliff launching?
--
David C. Barnhart
dcbii@lvl7.com
dcbii@dcbii.com
Date: Fri, 18 Oct 2002 14:44:48 -0700
From: "DavidRSw"
Subject: Re: Launching ,launching, launching
Hi Dave,> The technique I describe uses a >starting best glide AOA and
> pulling in through most of the launch ,, you genrally have so much speed
> at the end of the launch you can let the bar out to convert to altitude if
> needed ..
Previously, you have talked about having the glider carrying its own weight from the beginning of the launch and about moon walking. Moon walking means a higher aoa, doesn't it?
The more weight the glider carries at the beginning of the launch, the more lift it is generating and thus the more drag it is generating also. Thus making it more difficult to accelerate the glider. A lower (best l/d aoa) is not going to have the glider carry its own weight at the beginning of the launch.
> I guess it all about what gives you better feed back and control
> during the launch cycle...The worst thing I can imagine is a wing dropping
> with no way to shift weight to bring them level or at least hold it steady
> until I get off.. This droping wing or nose has been the cause of
> several launch crashes I ve seen and heard about ..
Why did your wing drop? If you got gusted and you have a high aoa, you'll get turned. If you got gusted with a low aoa, you'll go straight through it with nary a bump. You can of course move the glider around in wind without being hooked in and you can do it almost as easily during a launch run.
> Having the straps tight is the crux of the matter.. In a flex wing
>
> With a Ridged you slop the control bar around and you get spoilers..
> Last year I had a sprog problem.. It would manifest it self just as
> the wing loaded up foot launching .. One launch was seriously crooked at
> whitecap... The right wing droped like a rock ,or left rose and I was in a
> 70 degree turn ,steep bank .. wing inches off the ledge.
Well, if the tight hang strap is so good, then you should have noticed the turn before you even started your walk? Loose hang strap would have found it until later in the run, just like your's.
Yes, the crux of the matter IS the TIGHTNESS of the hang strap in the early stages of the launch. When launching, which technique is more likely to give one the best chance at complete control of the hang glider. If the hang strap is tight from the very beginning of the launch, it is easier to let the aoa increase (because it is already higher) to a higher aoa and have a very tight hang strap during the early part of the walk, jog. This leads to a stalled glider and loss of control. A looser hang strap at the beginning of the walk, jog, will usually make it more difficult to raise the aoa to a loss of control situation (position) or stalled glider.
There is nothing in either technique that *prevents* us from raising the aoa to a position that stalls the glider and results in a poor launch except good pilot awarness and response. This discussion has been about which technique gives a better chance of not launching with a too high angle of attack and associated consequences.
Dave, let me ask you, how easy it is for you to control the aoa when you are pulling the glider from the hang strap? In that position, your head and shoulders are ahead to the downtubes. Your arms are reaching behind you to the downtubes. Is this a good control position? By launching with the use of the shoulders behind the downtubes, my arms are in a very comfortable position, more or less similar to when I'm landing. See my point?
Thanks,
Dave Swanson
Glendale, CA
Date: Fri, 18 Oct 2002 15:02:55 -0700
From: "DavidRSw"
Subject: Re: Launching ,launching, launching
Hi Dave,I appreciate your help in walking through this subject.
> Hg gliders are weight shift control and all
> that takes place around the Hang( trim)postion .
That's true when they are flying as glider&pilot. But you can maneuver the wing without being hooked in by holding a zero lift aoa and exerting force against the groung. This is done all the time. One doesn't have to have the pilot's weight hanging off the glider to have maneuvering power. We maneuver through the downtubes and the ground in the earliest part of the launch. As the launch progresses, we transition to weight shift control.
> During the whole launch
> sequence you have no real roll control and your not flying the glider your
> just charging off the hill and hope to hell the thing flys when you get to
> the end of where ever your going..Luckly most sites round off and you
> will get in to the air on shear speed along ..You rely on shear mucle to
> hold the wing level ...
With the weight of the glider held by my shoulders wedged between the downtubes and hands lifting through the downtubes, I've got power to maneuver through my legs that are still on the ground. This is just like walking the glider to launch in gusty conditions. We certainly don't let the glider fly to launch in gusty conditions while we are hooked in, now do we.
> Plus the wings are much closer to the ground because you are
> holding it on or close to your shoulders..If a wing drops you have to
> inertia it back level .
Do you really think that 6 inches makes that much difference? With a lower aoa, each gust has LESS of an affect than with a higher aoa. With a lower aoa, each gust is a non-issue and the wing doesn't drop in the first place. In your situation with a higher aoa, if a gust lifts one wing, you have to PULL in first to get more control. I'm already there with my lower aoa.
> The argument about not being able to get good speed by towing
> the glider doesn't hold air.
A good launching speed is obtained faster with the lower aoa as the higher aoa situation has more drag that one has to overcome by pulling (pushing). Towing the glider into the air by the hang strap has the problem of the direction of that tow force. Dave, look at the angle of the hang strap that you are using to accelerate the glider into the air. It isn't straight forward, it's mostly down and only a little forward.
> I can moon walk a wing down a hill at 30 plus MPH
> .. Any where from the second to fourth step the straps are tight and I'm
> flying the glider with the control bar .. feeling the pitch, roll ,yaw just
> as in the air..
But YOU are not flying. Only the glider is. And that's not the point of this. You are controling a glider that is only capable of carrying ITS own weight. We need to get to glider&pilot to flying speed as quickly as possible. That's what's important, not just getting the glider to fly.
> Honestly ,,I did not dream up this techneque.. I learned it in
> Instructor cert .. From Greg DeWolf ,, 1988..
I can believe it. 1988 was a long time ago. Did Greg tell you of the time he and I flew the back-side of Kagel Mtn in NW winds and reached 7300'msl in wave?
> To me this is a very safe launch .. From Light FSL to windy cliff
the > feed back is the same ,, push with the shoulders, hold the pitch steady,
> let the wing rise tight on the straps as you lean into the run.. This is where
> it get complicated for some ... You have to be feeling the pitch , roll while
> powering the wing.. Of course the payoff is that you are flying the wing
> and if a wing drops you shift weight , if you hit lift you pull in.
If the wing encounters gusty turbulance, what do you do? Pull in? With a lower aoa, you are already there.
> Nose down, pushout .
With the lower aoa, you don't have to do anything. One just accelerates off the hill. Any turbulance is easier with a lower aoa.
> Im not talking about poping the nose the get the straps tight.. Set
> the AOA so the glider will lift as the run is started ... You can hold the
> wing down to get more inertia going in higher winds.. Sure you feel to
> drag of the wing ,but its not something that will hold you back.
But that drag is eliminated by having the wing at a lower aoa. That allows your force to be applied directly to glider acceleration instead of acceleration and overcoming that drag.
> That weight in
> the hang strap is a good thing ,, Its feed back its telling you how much lift
> the wing is generating .. you feel it in your hips and you feel it in the
> DTs..
If you feel it in your hips, you can't feel it in the downtubes. They are attached to each other except for pitch and roll. But any vertical lift of the wing is transmitted to the hips via the harness leg straps. With a looser hang strap, you do feel the glider moving up in your shoulders and hands.
>You're standing on the flatslope of Gunter, 8000' asl in the owens valley
> The switchy wind straightens is 10 mph stactic.. You set the pitch,
Good choice of an example. We've done our pre-stuff and we're on launch. We pick the cycle as you said, and pick the glider up. I'd set mine at zero lift aoa while just standing on lauch. Then maybe just a few degrees of up aoa just before starting the first step.
> Start your run ,,
I'd walk, then jog, holding the aoa in the same position. The weight of the glider is held through the downtubes wedged on the outside of my deltoid (shoulder) muscles and my arms wrapped down the backside of the downtubes and hands on the outside of the downtubes. The slight slope that I'm running down, sets an additional aoa and it starts to generate a little lift on the wing as I progress down it. I can feel it in my shoulders and hands as I'm carrying less and less weight as I reach the running stage.
> You let the glider rise to straps tight in the third stride>>>
But previously you'd said that you had tight straps before you started your launch. So you changed your technique for this fsl? By my 3rd step, I'm still carrying most of the glider weight on the shoulders. The gliders carrying a little. By the time that I'm running, there is very little weight left and the hang strap has become tight though not enough to lift me yet. And very quickly the glider has more airspeed so it begins to carry more and more of my weight until it carries it all and I'm taking big strides as the glider carries glider&pilot. At this point, since the aoa was low, I have accelerated with more than enough air speed for control. Any gusts are less upsetting to me because of the lower lift aoa of the glider compaired to your initial launch stages.
> Pour on the power >> 7th stride the glider is carring your weight and
> you could lift off ,but no way... You pull the bar in keep your feet on the
> ground and get three more powerful strides before the wing pulls you off
> at 30 plus mph airspeed.
But that's just my point. You had to change your bar position to keep your feet on the ground, I didn't. My aoa was set almost from the beginning for somewhere around best l/d air speed.
In order for you to power, you had to lean forward throught the downtubes to pull through the hang strap, I didn't. My shoulders (and eventually my arms as the glider slowly rises) were pushing on the back of the downtubes (picture a football player on a practice blocking sled). In your case, your body had a forward lean with your shoulders infront of the downtubes. The hang strap was angled down and a little forward of the attach point in order for you to pull the glider forward. As the glider begins to carry more weight, your weight wants to swing back under the hang point. You need to account for this. In my case, with the forearms behind the downtubes, I'm almost directly under the hang point all along, so smaller adjustments are necessary.
> you let the bar out to gain some altitude, fly out and turn right
> and start looking for that ride to 17k..
Yes, let the bar out to trim and go to the basetube. Angle right, toward the spine and road, and catch the resident thermal. After it's cored, zip up and settle in.
Thanks,
Dave Swanson
Glendale, CA
Date: Fri, 18 Oct 2002 15:45:41 -0700 (PDT)
From: Peter Lawrence
Subject: re: Launching ,launching, launching
I had to play launch monitor at Walts Point one weekend (so the Forest Service would let us fly there). I gave lots and lots of pilot briefings, and watched lots and lots of launches. We did not have any blown launches, but a couple of scarry ones. The scarry ones were where the pilot either choose to start his run back from the edge of the cliff and hope to throw himself into the air at the edge (rather than start at the edge and run down), or the pilot tried to hold his glider up and start with tight hang straps, or both. For all the reasons earlier stated earlier (not able to accelerate as well, much more likely to pop the nose up, not in as much control of the glider) the tight hangstrap method really is inferior. That there were, or are, instructors teaching this method does not make it good.What works at Walts Point is to lift the glider up and balance it on your shoulders when the wind looks right, keep the wings level and the keel level (no matter what the wind is doing) and then run down the cliff (its about a 40-degree slope) as fast as possible until the wing lifts you off.
I use the same technique (accelerating the glider by pushing my upper arms and shoulders against the down tubes) at both Walts Point and also super shallow launches like Gold Hill (Telluride, CO).
Moon walking is more of a gee-wiz technique suitable for both launching and landing on sanddunes at the beach where you have perfectly steady air all the time, but is not going to help in anything more difficult.
-Peter Lawrence, YMMV-vale, CA.
Date: Fri, 18 Oct 2002 15:44:55 -0700
From: "DavidRSw"
Subject: Re: Re: Launching ,launching, launching
Hi David B,I'd like to have a go at the following:
> For the benefit of those of us who are not normally foot launchers,
> maybe you should make it clear how these launch methods really apply.
> It sounds like all the argument is over hill or FSL launches, in
> contrast with cliff or mountain launches.
The technique I've been describing is almost the same for all types of foot launching. For hill or FSL launches, I'd launch as I've described.
> Most of the launches I've had the chance to use are of the type
> where you are off in 2 or 3 steps. What you are describing here,
> especially later, talking about 7th stride and so on, is much
> different. Unless there is significant wind coming in, it would
> be difficult on a cliff launch to hold the hangstraps tight in
> any case, and it seems like the DavidRSw type of launch would be
> the way to go. You never get to the moon-walk phase, and it
> seems to me that trying to hold the hangstraps tight and get the
> AOA correct would be more difficult than keeping the correct AOA
> from your shoulders.
>
> Are many of the western launches of the FSL or hill type
> rather than the "only room for 2 or 3 steps" type?
Kagel, Crestline, Elsinore, and Marshall are hill to FSL type launches. The Towers launch at Sylmar is a step launch, almost 45ř hillside, off a flat set up area. This launch needs one walk stride on the flat (don't try to launch from the flat) and the next 2, maybe 3 steps are down the face of the cliff wind or no wind. If the nose is high for these 2 or 3 steps, the wing will be mushing with a reduce control. The aoa should be low, almost as if one were flying down the face of the cliff. It's a thermal site with winds and thermals coming up the face. The lower aoa helps to manage these upsets.
> Also, does anyone use the hangstraps tight launch for cliff launching?
Let's try Beacon Ridge above Lake Isabella on the Kern River. It's an 800' ridge above the lake. The 15-20 mph afternoon wind blows up the canyon, across the lake, and straight into the face of the ridge. It's not too steep a launch. Add the wind and the ridge compression and we've got an exciting launch! The aoa must be at zero lift aoa as one walks to launch. This isn't smooth ridge lift at all. It's gusty ridge compression. Even with wire help, one gust and a tight hang strap too early can be unpleasant. It can lift a wireman right off the ground. With this high wind, the launch is with a tight hang strap before even one step, no way around it. The basetube is hitting the shins the aoa is so low. Wire crew pulling down on the side wires, low lift aoa (pointing down at the lake), push against the downtubes, count down, simultaneous wire release with a slight aoa rise, and it's a straight up launch for 3000' gain. With anything approaching a normal aoa, it could be deadly. If I'm comfortable using low aoa launches, it is one less worry. If I haven't practiced the low aoa, well.... Launching with a tight hang strap and no or a few steps is perfectly safe at Torrey.
Thanks,
Dave Swanson
Glendale, CA
Date: Fri, 18 Oct 2002 21:35:53 EDT
From: flymedave@aol.com
Subject: Re: Launching ,launching, launching
In a message dated 10/18/2002 6:20:10 PM Eastern Daylight Time, DavidRSw@msn.com writes:> Previously, you have talked about having the glider carrying its own weight
> from the beginning of the launch and about moon walking. Moon walking
> means
> a higher aoa, doesn't it?
>
When I say the glider is carrying it's own weight I dont mean pushing the glider up or pointing the nose up... I mean letting the glider rise up tight tight on the hang staps as you accelerate your run.. you set the AOA Low or about best glide depending on wind and slope....
Moon walking does not mean a high AOA it means you are pulling in and flying fast enough close to the ground to keep your feet kicking the ground .. How much you need to pull in depends on how steep the hill is .. Moon walking gives you the choice of when you leave the ground ..its just flying the glider..
Its true that most mt launches don't require much moon walking .. Most are just diving off a steep hill or cliff or twanging off..learning to hold the glider on the ground and flying the glider for a couple of stride before letting it pick you off has big benefits..
True ,my aim in every launch is to get the glider off my shoulders and lugging my weight as soon as possible but this is all done at a low AOA relative to the slope and the wind..
DaveH
Date: Fri, 18 Oct 2002 23:16:24 EDT
From: flymedave@aol.com
Subject: Re: Launching ,launching, launching
In a message dated 10/18/2002 6:07:37 PM Eastern Daylight Time, DavidRSw@msn.com writes:> Previously, you have talked about having the glider carrying its own weight
> from the beginning of the launch and about moon walking. Moon walking
> means
> a higher aoa, doesn't it?
> The more weight the glider carries at the beginning of the launch, the more
> lift it is generating and thus the more drag it is generating also. Thus
> making it more difficult to accelerate the glider. A lower (best l/d aoa)
> is not going to have the glider carry its own weight at the beginning of
> the
> launch.
> This is not true a glider will fly off your shoulders very nicely at
> best glide AOA ...If there is 10 mph of wind it is weight less to the pilot
> .. you don't need to hold it in your shoulders long ... second step and it
> rises tight.. You just hold the pitch and power on down the slope..
>
> I guess it all about what gives you better feed back and control
>
> > during the launch cycle...The worst thing I can imagine is a wing dropping
> > with no way to shift weight to bring them level or at least hold it steady
> > until I get off.. This droping wing or nose has been the cause of
> > several launch crashes I ve seen and heard about ..
> Why did your wing drop? If you got gusted and you have a high aoa, you'll
> get turned. If you got gusted with a low aoa, you'll go straight through
> it
> with nary a bump.
> You can of course move the glider around in wind without being hooked in
> and
> you can do it almost as easily during a launch run.
>
It's been my experience that when a wing drops and you don't have the glider loaded > you are running down a slope at a Low AOA .. There is very little you can do to straighten it ... That wing sticks out there 17 ft . It has lots of leverage on you and you have very little time to mucle it .. I have personally been hit by lots of crap in launching and am very glad I was in a postion to shift weight throungh the control bar ..
> > Having the straps tight is the crux of the matter.. In a flex wing
> >
> > With a Ridged you slop the control bar around and you get spoilers..
> > Last year I had a sprog problem.. It would manifest it self just as
> > the wing loaded up foot launching .. One launch was seriously crooked at
> > whitecap... The right wing droped like a rock ,or left rose and I was in a
> > 70 degree turn ,steep bank .. wing inches off the ledge.
>
> Well, if the tight hang strap is so good, then you should have noticed the
> turn before you even started your walk? Loose hang strap would have found
> it until later in the run, just like your's.
Yeah maybe it would have been better starting tight ... Just kidding ... This was a thermal mt launch .. the air was not smooth ... I didn't know it was the sprog problem at the time of course... The wing banked quickly second step into the launch and the only chance I had was to fly it straight ,, which I did .. I flew across the hill banked up with the right wing tip Inchs off the rock .. I was cranked all the way over to the left.. fianally it responded and rolled out .. The one thing I didnt do was panic.. I just did every thing I could do to fly it straight.. If it came to a crash as always, I would have pulled myself up in to the uprights and made that glider take the blow...
> Yes, the crux of the matter IS the TIGHTNESS of the hang strap in the early
> stages of the launch. When launching, which technique is more likely to
> give one the best chance at complete control of the hang glider.
> If the hang strap is tight from the very beginning of the launch, it is
> easier to let the aoa increase (because it is already higher) to a higher
> aoa and have a very tight hang strap during the early part of the walk,
> jog.
> this leads to a stalled glider and loss of control.
Its funny how we miss read or write our intents ... The technique I'm describing has the hang strap coming tight anywhere from the second to third step into the launch .. the glider rising is controled by the pilot.. Once tight and our weight is transitioning in to the wing and our control is much more natural and solid feeling
>
> A looser hang strap at the beginning of the walk, jog, will usually make it
> more difficult to raise the aoa to a loss of control situation (position)
> or
> stalled glider.
> There is nothing in either technique that *prevents* us from raising the
> AOA
> to a position that stalls the glider and results in a poor launch except
> good pilot awarness and response.
> This discussion has been about which technique gives a better chance of not
> launching with a too high angle of attack and associated consequences.
>
> Dave, let me ask you, how easy it is for you to control the aoa when you
> are
> pulling the glider from the hang strap? In that position, your head and
> shoulders are ahead to the downtubes. Your arms are reaching behind you to
> the downtubes. Is this a good control position?
Its very easy for me to control the glider AOA... I have a loose grip on the bar . Im just holding a little pitch pressure . I can make very quick correction to pitch and roll ..
Your arms are bent and low on the DTs and slightly in front of your sides..Same as if you had the glider on your shoulder leaning throught the bar only the glider is up above on the hang strap.. As you start your walk, jog ,run you lean forward through the bar .. as your body leans down you let the glider rise a bit and the straps come tight .. Its easy to hold the AOA steady and power in to the run...flying the glider using normal weight shift from the DTs ..
> By launching with the use of the shoulders behind the downtubes, my arms are
> in a very comfortable position, more or less similar to when I'm landing.
> See my point?
,Sorry, No I don't , ,, That sounds plain weird to me .. :-) You really dont have to be afraid to let the glider rise up tight on the straps.. Its not going to pitch up wildly..It does take practice but after a short time youo would not want to launch with out the natural feel of having a light touch on the Cbars and controling the speed and lift through your launch ..
Trying to hold the right AOA for what ever air I meet going down a hill would be very diffcult .. And if you are powering the glider by pushing with the shoulders and arms through the entire launch you are pushing below the center of lift and weight of the glider,, If there is any lift.. I'm pulling the glider through the center of weight and CG ... I have the natural pitch control of the control bar in my hands to make quick controls ..sometimes thy'er needed..
> Thanks, DavdH
Flexible is much too rigid, in aviation you have to be fluid. - > t
Date: Fri, 18 Oct 2002 20:19:03 -0700
From: "DavidRSw"
Subject: Re: Launching ,launching, launching
Hi Dave,> Moon walking does not mean a high AOA it means you are pulling
> in and flying fast enough close to the ground to keep your feet kicking the
> ground
Your moon walking definition is what got some of this all screwed up. I can't recall anyone in all my years of hg, thinking that moon walking was anything different than what Peter Lawrence called it: "Moon walking is more of a gee-wiz technique suitable for both launching and landing on sanddunes at the beach where you have perfectly steady air all the time, but is not going to help in anything more difficult."
> True, my aim in every launch is to get the glider off my shoulders and
> lugging my weight as soon as possible but this is all done at a low AOA
> relative to the slope and the wind..
My aim is to get to flying speed (a safe amount above stall) as soon as possible. The glider weight is taken off me automatically as this happens. Thanks and have a fantastic flying weekend,
Dave Swanson
Glendale, CA
Date: Fri, 18 Oct 2002 23:49:09 EDT
From: flymedave@aol.com
Subject: Re: Re: Launching ,launching, launching
In a message dated 10/18/2002 2:54:37 PM Eastern Daylight Time, dcbii@dcbii.com writes:> My lack of ability to experience such launches is probably the
> reason I don't even possess the FSL signoff. I never fly
> anywhere I could actually use it.
That doesn't mean you wont fly somre place where you will need that skill
..
Are many of the western
> launches of the FSL or hill type rather than the
> "only room
> for 2 or 3 steps" type? Also, does anyone use the hangstraps
> tight launch for cliff launching?
There are lots of western launches that are FSL... Plus at higher altitudes and light winds even a steep launch can demand good technique..
Basicly the techneque I'm describing gives you great feed back and the ability to fly a glider off any launch at speeds much faster then any man can run .. If you are relying on your foot speed you will find your self in a face plant at somepoint ..
Look at it like this > you tell a glider how fast to fly by setting the pitch... A training glider will go 35 mph at a low AOA .. can you run 35.?. A topless will go 60 mph can you run 60? .. BUt if the glider is carrying your weight and your feet are just kicking the ground as you pulling for more speed you can go really fast.. down over a hill ..
Next time you go to a training hill dont just try to get in the air .. Try the method I 've been describing .. when the glider is about to pull you off the ground pull in enough to keep kicking forward and see how far down the hill you can stay next to the ground .. See how fast you can fly still kicking the ground.. notice how much pitch and roll attention this takes while zooming down the hill .. but also notice how much control you have to let yourself fly off or pull in even more.. Its good to be real comfortable flying and running down a moderatly steep hill ...
Now try holding the glider in your shoulders and see how fast and far you can can run down the hill and control everything ...True we can fly th eglider by just holding down and in on the down tubes but does this give us sensitivity to all the things we need to pay attention to in launching ..
DaveH
Date: Fri, 18 Oct 2002 21:26:22 -0700
From: "DavidRSw"
Subject: Re: Launching ,launching, launching
Hi Dave,Peter said everything pretty well this afternoon. Follow his advice. A level keel is a low aoa.
> > The more weight the glider carries at the beginning of the launch, the
> > more lift it is generating and thus the more drag it is generating also.
> > Thus making it more difficult to accelerate the glider. A lower (best l/d
> > aoa) is not going to have the glider carry its own weight at the
> > beginning of the launch.
> This is not true a glider will fly off your shoulders very nicely at
> best glide AOA ...If there is 10 mph of wind it is weightless to the pilot
I disagree. I believe that a best glide aoa in a 10 mph wind will not generate enough lift to lift the glider's own weight.
> > .. you don't need to hold it in your shoulders long ... second step and it
> > rises tight.. You just hold the pitch and power on down the slope..
A lower aoa needs more than a few steps to generate enough lift to bring the hang straps tight in lower winds.
> It's been my experience that when a wing drops and you don't have the
> glider loaded > you are running down a slope at a Low AOA ..
It's been my experience that the reason a wing drops during a launch is because the other wing has been lifted. It was lifted because a gust generated enough lift over the rising wing because the entire wing had been held at a high(er) aoa than compared to what I'm advocating. Lower aoa's are less affected by gusts.
> > By launching with the use of the shoulders behind the downtubes, my
> > arms are in a very comfortable position, more or less similar to when
> > I'm landing.
>
> Trying to hold the right AOA for what ever air I meet going down a hill
> would be very diffcult .. And if you are powering the glider by pushing
> with the shoulders and arms through the entire launch you are pushing
> below the center of lift and weight of the glider,,
The lever arm is very short and since I started the launch with the aoa set accomodating this very force, it is perfectly controllable.
> If there is any lift.. I'm pulling the
> glider through the center of weight and CG ... I have the natural pitch
> control of the control bar in my hands to make quick controls
> ..sometimes thy'er needed..
A lower aoa is less affected by a gust, and thus minimal control is needed. If you are pulling the glider from the hang strap, your head and shoulders are ahead to the downtubes and your arms are reaching behind you to reach the downtubes. So as soon as you are lifted by the glider, you have to adjust your position as you swing back under the hang point. Doesn't seem like a better way to launch.
Thanks,
Dave Swanson
Glendale, CA
Date: Fri, 18 Oct 2002 22:44:42 -0700
From: Frank Schwab
Subject: Launching, launching, launching...
Okay, can we all agree that no one style of launching is best in all conditions?At the site in my backyard (Shaw Butte, Phoenix, AZ), we launch off a very short, nearly flat piece of asphalt that ends in a 10 foot drop-off to another relatively flat plateau, and we normally launch in 5mph gusts (up from a steady-state 3). Try doing that with the "walk, jog, run", "dive off the end for speed" or "moonwalking" techniques. Ya gotta get the glider going NOW, and ya gotta get it going fast, quickly. Shoulders behind the downtubes, hard push off holding the AOA using the hands with the shoulders as a fulcrum is the only way to generate flying speed by the time you get to the edge. The tight hangstrap boys ain't gonna get airborne on this launch.
Of course, our training hill (the Craters, near Flagstaff, AZ) is the only place I've blown a launch since my training days. It is a near-perfect hill for the "walk, jog, run" launch, and quickly penalizes those complacent H-IV's that try to launch the same everywhere. The surface is soft, composed of about 1000 feet deep of small, uncompacted volcanic cinders (think 1/2 inch pumice stone). The shape is classic gentle hill, flat on top becoming steeper as you go down the hill. Well, using my hard surface launch technique on a soft surface just didn't work. Pushed hard with my shoulders as my feet sank up to my ankles, which of course led to a glider wayyyyy out in front of me as I tried to catch up, and a very short "flight".
I think that on most launches, several different styles (if used in skilled hands) can be used safely. Some launches, however, may be severely limited in the launch styles that can be used safely. On a few, a launch technique peculiar to the site must be used to launch safely; you better have remembered to treat the local who drove you to the top really well before he briefs you on that technique.
And that's the way it is...
/frank
Date: Sat, 19 Oct 2002 08:10:55 EDT
From: flymedave@aol.com
Subject: Re: Launching ,launching, launching
In a message dated 10/19/2002 12:27:20 AM Eastern Daylight Time, DavidRSw@msn.com writes:> Hi Dave,
> Peter said everything pretty well this afternoon. Follow his advice. A
> level keel is a low aoa.
>
a level keel can be a high AOA at places like Walts point or other almost cliff launches..I set the AOA for what ever the site and conditions call for .. know this calls for some judgement but Ive. got the tools..
> > > The more weight the glider carries at the beginning of the launch, the
> > > more lift it is generating and thus the more drag it is generating also.
> > > Thus making it more difficult to accelerate the glider. A lower (best l/d
> > > aoa) is not going to have the glider carry its own weight at the
> > > beginning of the launch.
> > This is not true a glider will fly off your shoulders very nicely at
> > best glide AOA ...If there is 10 mph of wind it is weightless to the pilot
>
> I disagree. I believe that a best glide aoa in a 10 mph wind will not
> generate enough lift to lift the glider's own weight.
>
Really ? Try It .. I do it often ..Next time at the training hill try it ,,see what what AOA is needed to float the wing off your shoulders ..You could say you are going 15 mph y the sec or 3th stide and you don't think a wing will float up?
> > > .. you don't need to hold it in your shoulders long ... second step and it
> > > rises tight.. You just hold the pitch and power on down the slope..
>
> A lower aoa needs more than a few steps to generate enough lift to bring the
> hang straps tight in lower winds.
>
> > It's been my experience that when a wing drops and you don't have the
> > glider loaded > you are running down a slope at a Low AOA ..
>
> It's been my experience that the reason a wing drops during a launch is
> because the other wing has been lifted. It was lifted because a gust
> generated enough lift over the rising wing because the entire wing had been
> held at a high(er) aoa than compared to what I'm advocating. Lower aoa's
> are less affected by gusts.
>
A wing can drop also because it hits turbulence ,down air ,wind shadow,and gradient effects .. there is no lifting of one wing the other just goes down of loses lift...
> > > By launching with the use of the shoulders behind the downtubes, my
> > > arms are in a very comfortable position, more or less similar to when
> > > I'm landing.
> >
> > Trying to hold the right AOA for what ever air I meet going down a hill
> > would be very diffcult .. And if you are powering the glider by pushing
> > with the shoulders and arms through the entire launch you are pushing
> > below the center of lift and weight of the glider,,
>
> The lever arm is very short and since I started the launch with the aoa set
> accomodating this very force, it is perfectly controllable.
>
> > If there is any lift.. I'm pulling the
> > glider through the center of weight and CG ... I have the natural pitch
> > control of the control bar in my hands to make quick controls
> > ..sometimes thy'er needed..
>
> A lower aoa is less affected by a gust, and thus minimal control is needed.
> If you are pulling the glider from the hang strap, your head and shoulders
> are ahead to the downtubes and your arms are reaching behind you to reach
> the downtubes. So as soon as you are lifted by the glider, you have to
> adjust your position as you swing back under the hang point. Doesn't seem
> like a better way to launch.
It doesn't happen that way .. You are leaning through the bar in a semi prone postion and flying the glider in a nature hands on the Dts ..the tube sweep forward of the cg ... When the glider lifts you off you are in a very natural flying postion need no ajustments
Thanks
DaveH
Date: Sun, 20 Oct 2002 10:02:36 -0600
From: red
Subject: Re: Launching, launching, launching!
Wayne Hobbs wrote:> Is there any advantage in moonwalking down the side of the cliff as
> the wings builds up airspeed?
> Wayne
Wayne,
Sure! It keeps your body and glider away from solid rock (always a good idea, to me) by at least the distance required for your feet and legs. There will be considerations made for wind and terrain, but in general, I treat a cliff like a steep slope.
Windy, assisted cliff launches and still-air vertical cliff launches are entirely separate affairs, when compared to an ordinary cliff launch. No running is necessary on a windy cliff.
On the top of a still-air cliff, all of my running is done on the horizontal, not the vertical face. I try to hit the air at full flying speed, gliding (not diving) away from the cliff face. I put a toilet-paper streamer out over the cliff face, to one side of launch, so I know before I run that there is no wind (lift) to pop the nose up, waiting for me out there. If there is terrain out in front and below the cliff, that I could hit by a dive or stall, I just do not fly there on that day. Both the cliff and I will be there, on better days. That's the real trick to this sport, right? :-)
Guess a couple of decades of flying has one advantage - I'm no longer desperate for airtime. Maybe more accurately, I will no longer risk All Of My Tomorrow's Airtime hours for one high-risk launch today. Cheers,
Red
Date: Mon, 21 Oct 2002 16:39:32 -0500 From: "Roy Mahoney"
Subject: Re: Launching, launching, launching...
Frank said:>"...At the site in my backyard (Shaw Butte, Phoenix, AZ), we
>launch off a very short, nearly flat piece of asphalt that ends in
>a 10 foot drop-off to another relatively flat plateau, and we
>normally launch in 5mph gusts (up from a steady-state 3).
>Try doing that with the "walk, jog, run", "dive off the end for
>speed" or "moonwalking" techniques. Ya gotta get the glider
>going NOW, and ya gotta get it going fast, quickly. Shoulders
>behind the downtubes, hard push off holding the AOA using
>the hands with the shoulders as a fulcrum is the only way to
>generate flying speed by the time you get to the edge. The
>tight hangstrap boys ain't gonna get airborne on this launch.
>...
That's similar to the SE launch at Heavener, Oklahoma. Fairly flat with room only for 3 good steps to about a 10 foot drop off to a 4 or 5 to 1 slope. I find that tight straps help get a good start in light winds, with the following technique: Start as far back and with the wing held high as possible (not high AOA, high as in altitude), even standing on my toes. Pulling the glider hard down and forward initially fills the sail and makes my surge forward easier, no drag from the glider, actually if anything I get some added thrust. It's like a fall forward then surge. I do not wedge the glider in my shoulders but I have firm contact with the downtubes with my forearms, elbows and part of my upper arms. I have no idea when I transition to the bottle grip but I'm there by the time I'm in the air in the three steps, adjusting the dive to clear the bushes while ensuring adequate airspeed.
If at another launch where there's more room to run, there's no need to start with the glider so high, but my straps are tight within the first couple of steps anyway.
As long as the AOA is kept low enough, there's no real drag to overcome. In fact, there is a reason why birds initially evolved wings in the first place, when they used to be dinosaurs, because they could run faster with their little short proto-wings carrying some of their weight.
If you've ever tried foot racing with your hang gliders, you find out quickly that those who run with straps tight will outrun those who try to run with straps loose. The key is AOA control. Not too much, not too little.
Roy Mahoney
Poteau, Oklahoma
Date: Mon, 21 Oct 2002 23:04:43 EDT
From: flymedave@aol.com
Subject: Re: Re: Launching, launching, launching...
In a message dated 10/21/2002 5:41:32 PM Eastern Daylight Time, rrrr@alltel.net writes:> As long as the AOA is kept low enough, there's no
> real drag to overcome. In fact, there is a reason why
> birds initially evolved wings in the first place, when they
> used to be dinosaurs, because they could run faster
> with their little short proto-wings carrying some of their
> weight.
>
> If you've ever tried foot racing with your hang gliders,
> you find out quickly that those who run with straps tight
> will outrun those who try to run with straps loose. The
> key is AOA control. Not too much, not too little.
>
> Roy Mahoney
> Poteau, Oklahoma
>
HaHa ..Yeah the the first one to actually get airborne must have been a happy Dino. ..
This is what I've been trying to emphasis .. If you want speed get the straps tight pour on the power ,do some pitch control and you can go fast down a cliff ,FSl or anything in between .. plus your flying and controling when you leave the ground ...
Sadly,, I know of three blown launch this yr and all were the result of trying to run the glider to speed in light winds at too low an AOA and either the nose or a wing dropped and there was no way a person can catch a speeding glider or lever a dropping wing ...
I think this happens because we get it drilled into us not to pop the nose and pilots get used to diving off in lots of wind which requirs very little sensetivity to pitch.. just hold the nose down and drive forward .. You go into air coming up at a steep angle ,lift happens and you fly away .. this is what most East coast launches are ..
Then a pilot gets on a flat slope or even steep slope in light wind.. and charges down with the nose too low and no matter how fast you run the glider doesn't lift and it actually pulls away and noses down or drops a wing before you can push out and you have no way to pick a wing up..It Face plant time ..If you do manage to get off you are in a mush and may crash even better..
On the other hand if you learn to load the wing ,control the angle of attack you are always flying the wing after the first couple of steps and just adding power and speed to the situation ..The wing is giving you feed back all the way ..This is not a technique just for the bunny sand hill.. It keeps you safe and in control through every launch situation, with in reason :-) ..
I 've flown Ca coast and Mts ,Walts point, gunter , slide ,all the sites in lakeveiw, chelan ,Tompsons peak
DaveH
Date: Tue, 22 Oct 2002 18:33:05 -0000
From: "Wayne Hobbs"
Subject: Dazed and Confused (was launching)
One of the things that a local instructor encouraged me to try (Tony Middleton), was that as I prepared to launch, at those last few moments, I should bring my feet together, slowly lean forward until I must run or fall on my face and then continue with whatever launch method you use.What this seems to do, is to get the wing moving before the pilot and not the other way around. This seems to really help reduce nose popping, which with my Exxtacy is not much of a problem as it tends to be nose heavy when about to launch.
You younger pilots might try this sometime on a moderate and safe launch site to experiment with it. I think you'll find it to be a nice trick to have in your bag.
Wayne
Date: Tue, 22 Oct 2002 19:12:04 -0000
From: "hgxc"
Subject: Re: Dazed and Confused (was launching)
Talk about a thread gone awry. Launching a glider is as individual as the body type and athletic skill of the pilot. Basically you pick the sucker up and grip it in a way that you can control it and no one can take it from you. I like to wrap my arms around the tubes and spread my hand over the outside (Grapevine I believe). I use this because I have a good set of shoulders and can leverage my arms for pitch and roll control as I run. I also like this grip because I used to use the grapevine in my wrestling years and it brings back pleasant memories.With the help of a cord crew (I don't have side wires) I get to the top of the rock, get a steady breeze clear my cord folk clear my front wire guy and blast like a sprinter rising out of the blocks. I do slight forward roll as I am clearing to get the same advantage as Wayne does but I can always abort until I take the first step. Our launches have minimal room to run and in light days I want some speed to pay of so I can make my first turn tight to the ridge. When you drag that beast up a 25 minute trial you don't want to sink out in scratchy days. I see people ramble off all the time and sink after launching. Sometimes this will cost them a save. Speed has always been my friend and I try to get as many steps in as I can even in windy days.
I say grip that bastard like it's the last roll on a Sunday dinner and run like you just stole a pizza out of the van during the old days at the dorms.
DC
Date: Tue, 22 Oct 2002 22:59:06 -0000
From: "petebty"
Subject: More launching comments
--- In HangGlide@y..., Someone wrote:> > Sadly,, I know of three blown launch this yr and all were the result of trying to run the glider to speed in light winds at too low an AOA
I really don't understand this. When footlaunching you have to gain enough airspeed to keep the glider above stall speed no matter how gusty it is. For this reason I keep the nose down and run as though I'm expecting a 10 mph tail wind before slowly letting up the nose and letting the glider lift me and legs-a-running into the air. Airspeed is control, and you need to keep the nose down to achieve that airspeed.
Pete
Date: Wed, 23 Oct 2002 09:31:11 EDT
From: flymedave@aol.com
Subject: Re: Re: Launching, launching, launching...
In a message dated 10/22/2002 6:51:25 PM Eastern Daylight Time, peterbatey@hotmail.com writes:> Airspeed is control, and you need to keep the nose down to achieve
> that airspeed.
> Pete
>
I agree you need to keep the nose down,but we also need to control AOA to produce lift .. Get the nose to low and no matter how fast you run you dont produce lift.. Get it to high we produce to much drag to get speed ... Obviously controling AOA is a critcal function of any launch.. I guess the dabte is about when to let the straps come tight ..
daveh
Date: Wed, 23 Oct 2002 07:36:49 -0600
From: "Kevin Frost"
Subject: Re: Re: Launching, launching, launching...
I've only seen this on the training hill. In real life it's always too much angle of attack, or too little speed.KF
----- Original Message -----
From: "petebty"
To:
Sent: Tuesday, October 22, 2002 4:50 PM
Subject: [HG] Re: Launching, launching, launching...
> --- In HangGlide@y..., "DavidRSw"
> > Dave,
> > > Sadly,, I know of three blown launch this yr and all were
> the
> > > result of trying to run the glider to speed in light winds at too
> low an
> > > AOA
>
>
> I really don't understand this. When footlaunching you have to gain
> enough airspeed to keep the glider above stall speed no matter how
> gusty it is. For this reason I keep the nose down and run as though
> I'm expecting a 10 mph tail wind before slowely letting up the nose
> and letting the glider lift me and legs-a-running into the air.
> Airspeed is control, and you need to keep the nose down to achieve
> that airspeed.
Date: Wed, 23 Oct 2002 08:16:07 -0600
From: "Kevin Frost"
Subject: Re: Re: Launching, launching, launching...
Ya know, this thread went on and on just like this several years ago. And I finally said what I'm gonna say again .....you guys are thinking waaayyyy too much.Launching a hangglider is something that is better off not over analyzed. When you are on launch you need a clear mind. You need to not be thinking about when you strap is 'supposed' to get tight or any of that kind of stuff you are gonna screw yourselves up thinking like that. When you have committed to launching and have taken that first step the time for thinking is long over, you should be launching on pure muscle memory and living in the moment. You should be like an arrow at the moment of release.
Get on launch, pick your cycle, walk, jog, run with the attitude that your goal is to run all the way down the hill, keeping perfect angle of attack the whole entire time. That's all......any other information is clutter.
If you are not getting prefect results every time then it is time for a day on the training hill. Thinking about it, analyzing it, will solve nothing.
KF
----- Original Message -----
From:
>I agree you need to keep the nose down, but we also need to control AOA
> to produce lift .. Get the nose to low and no matter how fast you run you
> dont produce lift.. Get it to high we produce to much drag to get speed ...
> Obviously controling AOA is a critcal function of any launch.. I guess
> the dabte is about when to let the straps come tight ..
Date: Wed, 23 Oct 2002 15:06:09 -0000
From: "Rodger Furey"
Subject: Re: More launching comments
.I know of three blown launch this yr and all were the result of trying to run the glider to speed in light winds at too low an AOA..In 22 yrs of flying hang gliders, I've never seen a blown launch as a result of a too low AOA. I've seen plenty of blown launches as a result of too high an AOA.
For a number of years I felt it was better to have the nose a little low than a little high when launching. Until this happened to me.
Warning, story:
Faced with a long shallow launch and a semi-strong gusty wind I wanted to make sure I became air born with plenty of speed, which meant a long sustained run. The last thing I wanted was to pop the nose early and find myself fluttering in the air with little control and a good 50+ feet of real estate to traverse before the ground dropped away. With that in mind I began my launch with the nose just a little low. It only took a few steps before I realized that just a little low was just a little too much. That semi-strong gusty wind was pushing the entire glider down on my shoulders with surprising force. Before I knew it the glider was on its wheels rolling down the woodchip strew incline dragging me, on my knees, behind it. I desperately tried to abort the launch (big whack!) by pushing the nose over before I reach the rocks at the end of the launch but that wasn't working either. Suddenly I was lifted straight up in the air and I though, "Ok, not the rocks, the trees." It took a moment before I realized that the airspeed felt pretty good and I actually had control of the glider. I didn't look this particular gift horse in the mouth. I immediately went prone, pulled in the bar and got the hell out of there. Later in the LZ my buddies came over to give me a well earned razing about my unique launch technique. As I was folding up my harness a large pile of woodchips fell out of the boot of my harness as a testimony to my blunder. For some reason my friends though that was the funniest pile of woodchips that had ever seen.
Now I prescribe the nose angle `just right' theory.
Rodger
Date: Wed, 23 Oct 2002 15:11:49 -0000
From: "skipfreitas"
Subject: Take Off
KF wrote,"keeping perfect angle of attack the whole entire time. That's all......any other information is clutter"
Not to perpetuate this almost endless thread but I must say I like the way Matt Tabor put it to me once.
Manage the wing.
Date: Wed, 23 Oct 2002 15:12:25 -0000
From: "Wayne Hobbs"
Subject: Re: Launching, launching, launching...
When you have> committed to launching and have taken that first step the time for thinking
> is long over, you should be launching on pure muscle memory and living in
> the moment. You should be like an arrow at the moment of release.
>
> Get on launch, pick your cycle, walk, jog, run with the attitude that your
> goal is to run all the way down the hill, keeping perfect angle of attack
> the whole entire time. That's all......any other information is clutter.
>
> If you are not getting prefect results every time then it is time for a day
> on the training hill. Thinking about it, analyzing it, will solve nothing.
>
> KF
It really is a kind of zen thing. When we have these launch discussions, I can't even remember how I do it. I just do it!
One of the most important things to me, that I believe makes some launches better than others, is the committement you make to the launch. Launch is no time to be tentative. Launch should be like storming the beach at Normandy. Total committment.
Date: Wed, 23 Oct 2002 17:50:31 -0000
From: "John Wiseman"
Subject: Re: Take Off
--- In HangGlide@y..., "skipfreitas"> KF wrote,
> "keeping perfect angle of attack
> the whole entire time. That's all......any other information is
> clutter"
>
> Not to perpetuate this almost endless thread but I must say I like
> the way Matt Tabor put it to me once.
>
> Manage the wing.
A couple of years ago, I was about to make my first cliff launch at the 25th anniversary party for the High Rock, MD site. Tex Forrest was guiding the group of us H2's who were getting ready to line up. I had the most experience, so he put me at the head of the line and told me that "There are 3 things you need to remember about taking off here. Number one is to stand on launch at the very edge with your wings in the windstream, with your shoulders wedged in the downtubes to drive off the ramp with. Number two is two make sure your wings are perfectly balanced and you are coordinated with your wire crew."
I was nervous, but I did still remember how to count to 3, so I said "What is the third thing?"
His immediate reply was, "Don't F*** up."
john wiseman
Date: Wed, 23 Oct 2002 19:27:52 +0000
From: "Mark Lukey"
Subject: Low AOA blown launches: another perspective
A friend who will remain nameless sent me the following description of how to blow a launch using the low AOA tactic. I've never done this, but it sounds like it could be effective.>...the pilot launches the wing at a low AofA and finds himself running hard
>and just a little bit behind the glider. He tenses up a shade, grips a bit
>harder and then tends to pull down on the down tubes. This causes a very
>slight dive which accelerates the glider out ahead of him more which causes
>more anxiety/fear, a tighter grip, he pulls down on the tubes harder which
>dives the glider more which.... you got the idea. Next thing you know
>his hang strap wraps over his shoulder, he's leaning way forward, pulling
>down real hard and the control bar buries into the ground. Whack, crash,
>burn, ouch, damn, .... you got the idea.
Date: Thu, 24 Oct 2002 02:50:37 +0000
From: "Dan Schroeder"
Subject: Re: Re: Launching, launching, launching...
"run with the attitude that your goal is to run all the way down the hill"KF
Kevin's got it!
The number one reason for blown launches is having the wrong mindset prior to even starting your run. "Expecting" to become airborne is what causes premature wing loading and popped noses during a launch.
This is where the idea of flying the glider from the hang straps has merit. After two blown launches at the Craters (Flat slope launch), I changed my launch methods. I now do the walk, jog, run, thing while powering the glider through my shoulders. I then follow it up with a secondary pull in once the hang straps are loaded. The result is often several extra power steps.
The main thing is to pick either the end of the launch ramp or a spot way down the slope and fully intend on reaching it with your feet running. The secondary pull in should also be done, especially on flat sloped launches.
Another problem I have noticed comes when using a ramp that has a flat staging area on top. Pilots who choose to start with their feet on the top flat area are much more likely to pop the nose during their run. I recommend starting with both feet on the sloped surface. The result is that your feet can generate more power from the start and the nose is naturaly lowered to match the ramp angle.
Dan
Date: Thu, 24 Oct 2002 06:52:26 -0000
From: "thermaleo"
Subject: Re: Launching, launching, launching. launching,launching, launching, laun..
Wow, what a long, thought provoking, and interesting thread! I read every one of these posts, from Warren's blown launch to David Swanson's and David Hopkins' eloquent discourses. Thanks everyone.There are two critical moments in flight - take off and landing, (that's 'cos, folks, the ground is close!) Of these I believe that take off or launching is the most likely to hurt you or kill you.
When landing, you have flying speed (hopefully!) and unless you are unlucky or just plain inept, you can usually contact the ground in a manner unlikely to injure you. But if you fail to take off you are more likely to be injured or killed.
I wish I knew what I do when I launch. I'm so wrapped up in the moment it's hard to tell. I'm so pent up, excited and focussed, then it's all over so quickly. (Unfortunately the sticky bit is at the beginning - when I'm standing on launch sweating!) I think I use the "arms wrapped round the downtubes, thumbs in front method" - this gives good pitch and roll control. I try and get in a slow pace at first, to get the glider moving, hold it down, and run like hell, until I can't stay on the ground any longer, (in which case I usually have so much airspeed that I can zoom up off launch), or I run out of room, in which case I either pull in, or push out, depending on how she's flyin', if you see what I mean!
I never notice the transition - it's automatic. I never go to the base tube until my feet are off the ground, and then I do it in the same way as when I land, one hand up, one down.
Perhaps a lot more videos of pilots launching would help. There are obviously many different styles, depending on the site and the current theory of the day. But it does seem that two important elements emerge, in all but windy conditions, a slow pace or two to start, as much as anything to overcome the inertia of 75lbs of glider as anything else, then a hard acceleration, with the emphasis on flying the glider so that it carries its own weight,in effect, whilst the pilot drives it off the hill. Of course at this point the straps are tight, but you aren't allowing the glider to pull you off the ground. If you have lots of room you can take big steps and moonwalk it off, if you have a ramp you have to run as hard as you can, with the glider basically flying and supporting its own weight as you do so.
Example. St John Mtn, in Northern California. The launch, at 6000MSL, is a shallow dirt ramp, approx 25 degrees slope, 45 ft long, then a 3 ft drop off, to a similarly shallow slope of nice jagged lava rock and scree. The rock and scree face is bordered with 15 -20 ft high oak scrub and pines 150 ft further down the slope. It's a nasty place to blow a launch, (but we do it, because we are heroes who have no fear......!) Oh, I forgot to tell you, winds are usually less than 5 mph and typically 45 degrees cross.
When you go off the end of that ramp, you gotta be flying. There's no room for sinking. There's an urgency about this launch that's entirely absent from a similar slope covered in grass, with no trees in front. No moon walks at St. John I can assure you. The most common faults are jackrabbit starts, which usually results in a popped up nose, getting a wing up right at the start of the run, (usually as a result of a jackrabbit start), and pulling in too hard and diving off the end of the ramp, (which is somewhat safer, because at least the pilot has airspeed).
When you think about it, launching off a mountain is an amazing thing. Here I am, in my hang lider, and I'm going to RUN off this hill, and maybe fly a 100 miles. Or just to the LZ. Whatever, it's still the coolest thing to do. Pay attention when you do it. It's certain to get the attention of the gods.
Leo Jones
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