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#1
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![]() Bob C wrote: Very well written article. Bob, I beg to differ.It is a terribly written article!I have been at this a long time, and I have seen this type of pilot before.What the author is doing is using faulty logic and baseless asumptions to justify a completely non standard way of doing things.The author addressed a couple of issues with this approach method while completely ignoring others. This is a 'standard' airshow sailplane approach. Bob, should we all fly like we are at an airshow?I have seen two power fatalities and a near fatal glider crash at fly ins where pilots were doing "Standard" airshow stuff. Gives you exceptional glidepath control, excellent control authority and makes a stall/spin highly unlikely (though not impossible). One of my tricks for setting up a perfect spot landing. Now you Bob (Just like the original author) are applying some faulty logic.You tout the percived benifits of this approach while ignoring the fact that it creates more hazards than it solves. That being said; as with any new technique, don't try it the first time without the assistance of someone experienced in the technique. Or better yet, dont try it unless you have a specific reason to. It may be possible to overstress the glider. Be extra cautious of this technique when switching from a 2-33 to a higher performance glider. The extra energy you're carrying may be more than you realize. No argument here!I think this stunt would only work with a small range of training ships or a looooong runway.Not to mention the fact that the author is flying outside the POH and FARs AIM etc.. There are advantages in learning where the edges of the performance envelope are, but explore carefully with the help of an experienced pilot. There certainly are, but not in the traffic pattern! Being comfortable on a fast, low approach might come in handy when you discover power lines while setting up an out landing. But it will have the oposite effect with a more likely senario like a fence or ditch at the other end of the approach. Fly Safe, K Urban |
#2
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I agree as well, to a certain extent.
High speed approach breaks down with higher speed gliders -- a point drilled into me when I was a primary student 20 years ago (energy = 1/2mv**2, so picking up 5 extra knots over the 50 knot standard approach speed of a K21 results in 21% more energy, resulting in landing waaay down the runway). However, there are a couple of cases where zooming to higher airspeed is needed, and it's important to point these out. Reichmann describes the most extreme of these in "Cross Country Soaring" in his outlanding section. If an obstacle is recognized while on short final, the pilot can dive at the obstacle and use the extra kinetic energy to make a low-G parabolic maneouver over the obstacle. He also describes a lesser version in coping with steep landing fields -- if you have to land uphill on a steep slope you should zoom towards the slope so that you have extra energy to make the more exaggerated flare required. I've also had to use the technique to cope with extreme sink on short final a few times over the years. In my early years I flew at Harris Hill, which had a really bad downwash on short final with certain wind conditions. More recently I had a student act backwards when he encountered a downwash on final. I kept saying "faster", but he kept pulling the stick back, until I had to take the plane and make a zoom approach. Which brings up the reason we should at least discuss this with all our students. Without some training on the issue, they will tend to react to sink in the pattern by pulling back on the stick, which leads to low stall/spin accidents or hard landings when they don't have the energy to flare. It's vital to push the stick Forward! in sink, even when you're low. -- Matt McKrell CFIG KM wrote: Bob C wrote: Very well written article. Bob, I beg to differ.It is a terribly written article!I have been at this a long time, and I have seen this type of pilot before.What the author is doing is using faulty logic and baseless asumptions to justify a completely non standard way of doing things.The author addressed a couple of issues with this approach method while completely ignoring others. This is a 'standard' airshow sailplane approach. Bob, should we all fly like we are at an airshow?I have seen two power fatalities and a near fatal glider crash at fly ins where pilots were doing "Standard" airshow stuff. Gives you exceptional glidepath control, excellent control authority and makes a stall/spin highly unlikely (though not impossible). One of my tricks for setting up a perfect spot landing. Now you Bob (Just like the original author) are applying some faulty logic.You tout the percived benifits of this approach while ignoring the fact that it creates more hazards than it solves. That being said; as with any new technique, don't try it the first time without the assistance of someone experienced in the technique. Or better yet, dont try it unless you have a specific reason to. It may be possible to overstress the glider. Be extra cautious of this technique when switching from a 2-33 to a higher performance glider. The extra energy you're carrying may be more than you realize. No argument here!I think this stunt would only work with a small range of training ships or a looooong runway.Not to mention the fact that the author is flying outside the POH and FARs AIM etc.. There are advantages in learning where the edges of the performance envelope are, but explore carefully with the help of an experienced pilot. There certainly are, but not in the traffic pattern! Being comfortable on a fast, low approach might come in handy when you discover power lines while setting up an out landing. But it will have the oposite effect with a more likely senario like a fence or ditch at the other end of the approach. Fly Safe, K Urban |
#3
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Very well written article. This is a 'standard' airshow
sailplane approach. I've done it a thousand times. Gives you exceptional glidepath control, excellent control authority and makes a stall/spin highly unlikely (though not impossible). One of my tricks for setting up a perfect spot landing. That being said; as with any new technique, don't try it the first time without the assistance of someone experienced in the technique. (I was taught a similar approach by Les Horvath.) Just because it has advantages doesn't mean there aren't ways to screw up. The higher speeds may cause the controls to be 'twitchy', possibly leading to a disastrous PIO situation. The spoilers (especially Grobs) may behave very badly when deployed at high speeds. It may be possible to overstress the glider. Be extra cautious of this technique when switching from a 2-33 to a higher performance glider. The extra energy you're carrying may be more than you realize. There are advantages in learning where the edges of the performance envelope are, but explore carefully with the help of an experienced pilot. Knowing the parameters may give you the advantage you need to get out of a sticky situation someday. Being comfortable on a fast, low approach might come in handy when you discover power lines while setting up an out landing. I've seen the results of trying to go over without enough energy... At 21:48 31 October 2006, wrote: Here is something you more experienced pilots might want to comment on. Being a pilot of much less experience, it just looked like an interesting thing to see comments on some of the points the pilot makes.. I came across this 2005 article while just wandering about on the web. Scroll down to the high speed approach article. You'll need acrobat reader. http://www.pugetsoundsoaring.org/new...ow_10_2005.pdf |
#5
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On Wed, 01 Nov 2006 07:43:51 GMT, Jack wrote:
He can do a conventional approach, when he must. Can all of us do his preferred "high-energy" approach, safely, consistently? If so, then we are better qualified to criticize. Why would anyone do such an extreme approach at all? Depsite all his well-written words, there is no chance that he is able to perform a spot-landing this way. Not to mention his surprise if he should try this in a high performance ship with an L/D beyoond 35... lol. Bye Andreas |
#6
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I am no instructor, but this seems to be a poor display of how not to
land a low-performance glider on a long runway. It would not be a good technique for a high performance glider in a small outlanding field. =20 I fly from a hill-top site with plenty of wind gradients and cliffs and forests for under/overshoot. Yes, the recommended 1/3 wind speed added to the approach speed but not this. =20 I think this pilot needs some instruction on better circuit planning/energy management, if he is going to fly other gliders (or aircraft) and if he is receptive to comment. I agree with the instructors who consider this a "fail". =20 Unimpressed. =20 Rory=20 =20 =20 At 21:48 31 October 2006, wrote: Here is something you more experienced pilots might want to comment on. Being a pilot of much less experience, it just looked like an interesting thing to see comments on some of the points the pilot makes.. I came across this 2005 article while just wandering about on the web. Scroll down to the high speed approach article. You'll need acrobat reader. http://www.pugetsoundsoaring.org/new...ow_10_2005.pdf |
#7
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As Zulu pointed out, the Va speed of a 2-33 is only 65 MPH. The Vne is only
98MPH. That's when they were NEW! The 2-33 is an old glider and the years have not been kind to them. Many are showing obvious signs of metal fatigue in the upper wing skins. I know of several that have a dozen patches in the "D" tube. My personal rule is to NEVER fly a 2-33 faster than Va. I think it's a real problem that many tugs can't comfortably tow a 2-33 slower than its Va airspeed since you may well need full control deflection on aero tow. Flying a pattern and approach at 85 in a 2-33 is insane. Given their age and condition, it's only a matter of time before some cowboy pulls the wings off one. Bill Daniels wrote in message oups.com... Here is something you more experienced pilots might want to comment on. Being a pilot of much less experience, it just looked like an interesting thing to see comments on some of the points the pilot makes.. I came across this 2005 article while just wandering about on the web. Scroll down to the high speed approach article. You'll need acrobat reader. http://www.pugetsoundsoaring.org/new...ow_10_2005.pdf |
#8
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![]() Bill Daniels wrote: Flying a pattern and approach at 85 in a 2-33 is insane. Given their age and condition, it's only a matter of time before some cowboy pulls the wings off one. Bill Daniels Those Schweizers are pretty stout. He will probably only be able to bend them badly unless his horse is riding along in the back seat too. Seriously, I totally agree with you Bill. It's nuts. Hey, did your email change? Been hoping to hear back from you on the Amazing Lark Rigging Aids question. Matt Michael wby0nder@ A Oh L dot com |
#9
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![]() wrote: Here is something you more experienced pilots might want to comment on. Being a pilot of much less experience, it just looked like an interesting thing to see comments on some of the points the pilot makes.. I came across this 2005 article while just wandering about on the web. Scroll down to the high speed approach article. You'll need acrobat reader. http://www.pugetsoundsoaring.org/new...ow_10_2005.pdf Leaving aside other real concerns (e.g. flying 20 mph above Va in the turbulence of hills and trees) and the spurious concerns (e.g. frozen divebrakes), we're left with a pilot who has a fundamental misunderstanding of glider performance in ground effect. I don't have the energy (pun intended) to play with the numbers in his scenaio to show exactly how L/D at 85mph over the threshold at height X vs. the more conventional 55 mph or 60mph over the trees at height Y work out. He will argue that he can achieve an L/D of 5:1 vs. 8:1 for the conventional landing. He'll then point out that he will glide only 200 feet from treetop height vs 400 feet for the conventional landing. Something like that. The problem is, what does it take to stop from 10 feet and 55mph vs. 10 feet and 85mph? Since L/D in ground effect increases significantly (where significantly is anywhere from 20% to 30% for high-aspect ratio airfoils), the amount of time that you spend decelerating in this higher lift condition is extremely important to overall stopping performance. Anecdotally, we all know (or should know) that the "float" in ground effect will greatly outweigh the advantage (if any) in this approach. I suspect the author will argue that there's nothing wrong with just flying it on "smoothly" at 70mph and letting the wheel brake and skid do their thing. I sure hope he's not expecting to hold the ship at 5 feet and ever so slowly rotate while mainting 5 feet as the aricraft slows down from 85mph to a more reasonable 40mph or less touchdown speed. If so, I challenge him to accomplish any landing over a 30 foot tree line in less than 1,000 feet. Of course this works fine on the airshow circuit or at a field with clear approaches as an exercise to show the performance boundaries of the aircraft. Let's not discuss what happens in a rough field or a short field :-) |
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