This is a summary of all the e-mail and articles responding to my question about flying high performance gliders. I'd again like to thank everyone who responded for sharing their thoughts and their knowledge with me and the rest of the net. It has been quite valuable. A few details: I have included my original question and the responses, both e-mail and posts already made to rec.aviation.soaring. The e-mail replies are first, and there is a line preceding that group of replies stating E-MAIL RESPONSES. The net postings all follow a line stating NET RESPONSES. Each item is separated from the others by a line of ='s. I have edited the responses to try to keep this summary reasonably compact. I shortened lines to <80 characters and I removed echoing previous posts if I felt the new text did not require it. I did leave the From and Subject lines for each entry. In one instance I was requested by a non-native English speaker to correct spelling errors. So if you notice numerous spelling errors in a posting, that may be the one I corrected :) I think I have been careful enough to not change the meaning or intent of the original author. However, if you feel I have inappropriately modified something you wrote please let me know, and I will post a correction. Finally, if you wish to follow-up to something you see in this summary, please post it to the net. If you cannot (or do not wish to) post it yourself, send it to me, and I will post it for you. I do not intend to post a follow-up summary, and interested readers may wish to include your additional comments in the summary. Once again, many thanks to you for taking the time and trouble to respond to this question. Regards, Tony ============================================================================ ORIGINAL QUESTION ============================================================================ From: bible@iastate.edu (Anthony E Bible) Subject: QUESTION: Flying High Performance Gliders I'd like to hear some comments about the differences between flying low performance gliders and high performance gliders. I believe high performance implies something with a significantly higher L/D than the trainers, say, 35:1 or greater. Pick a greater or lesser ratio if you'd rather. Thinking about it some, all I could think of for differences is higher speeds and retractable gear. Are there others? Are they "twitchier" to fly? (Sorry for the technical terms.) Do they handle different on tow? Anything you'd care to share would be appreciated. Regards, Tony ============================================================================ E-MAIL RESPONSES ============================================================================ From: latyr@iastate.edu Subject: Re: QUESTION: Flying High Performance Gliders Basically, the fundamental guiding principle of the serious soaring addict has been laid down by Platypus of Sailplane & Gliding: "There Is No Substitute FOr Span" ( TINSFOS ) What it all boils down to: Short Span: low performance gliders with short wings able to land in the narrow short fields which they often frequent while on cross-country outings. Medium Span: mid performance sailplanes able to pass up the narrow short fields frequented by 1-26's and Da Vinci in favor of landing out in the fewer and farther between fields needed to accommodate the additional wingspan. Long Span: higher performance sailplanes which do not land out in fields of any kind because that would be very very bad. However, airports are spaced at good enough intervals that this should not be a problem. Very Long Span: Australians have a term for 150 km triangles flown in these ships: "FINAL GLIDE". Keep looking up! The sun will shine again soon... but the field will be underwater... [Note from AEB: Les and I are in the same gliding club. Spring is creeping in, ever so slowly, on big, muddy, sloppy feet.] Les Tyrrell, latyr@iastate.edu ============================================================================ From: rh@craycos.com (Robert Herndon) Subject: differences between hi/lo perf. gliders IMO, and I'm not one to trust on this, one of the most significant differences between high and low perf gliders is the difference between Vx and Vy. In a high perf glider, you want them to be far apart so that you have both good penetration and good thermalling behavior. Beyond Vy, you also want the glide ratio to drop relatively slowly with speed. Low performance gliders (e.g., 2-33, 1-26) have lots of parasite drag that limits high speed performance. Glass ships do much better. -r ============================================================================ From: Ove Kristian Pettersen Subject: Re: QUESTION: Flying High Performance Gliders I have used a K-8 during my training-time. Now I am allowed to use an LS-4. Of course there is a difference in L/D, but there is something even better. The polar is much flatter on an LS-4 than a K-8. That means that it does not matter if one have a bit headwind back to the field. One just pick up some more speed and glide back as if there was no headwind at all. With a K-8 one could never push for more speed( a bit perhaps) but one will end up on the ground, but not at the field. We have a hang 5-6 km away from our main field. Works only when one gets front wind back to the field. It's impossible with an old glider. A glass-ship finds it perfect( of course this have to do with the L/D-ratio too). I would say that a high performance glider is the one with: * a high L/D-ratio * possible to vary glider-speed around speed of best L/D without loosing too much height. * fly real slow (good for centering thermals) -- ------- ovekp ============================================================================ From: braner@trantor.emba.uvm.edu (Moshe Braner) To: bible@iastate.edu Subject: Re: QUESTION: Flying High Performance Gliders The ability to cover more ground faster and with less altitude loss means it is MUCH easier to find lift and stay up. Also, modern gliders are quieter and more comfortable and have better visibility. It all adds up to a MUCH more enjoyable flight! - Moshe (working on my ASK-21 checkout) ============================================================================ From: Matti Huoviala Subject: High performance sailplanes... This topic could be discussed more widely in rec.av.soaring, but since I have not seen any reply as of yet, I'll just email my comments to you. First I feel need to declare my ( and Finish ) idea of high performance sailplane. We regard a sailplane to be high performance if it has retractable gear and provision to carry water ballast. With sailplanes we people in Finland fly, this means L/D 35 or more. 35 is poor. Basically a competitive ship is high perf. High performance is also a question of ship's speed polar, in other words at what speed the ship will get its best L/D or what its sink rate is at 130 kts or so. ASK-21 would be high performance if it would do promised 35to1 but definitely it is not, since it is slow. Opinions here tend to call a ship high perf. when it has dry L/D more than 40:1 at around 65 kts, water carrying capacity up to 170 kg ( 300+lbs). > Thinking about it some, all I could think of for differences is higher >speeds and retractable gear. Are there others? Are they "twitchier" to fly? >(Sorry for the technical terms.) Do they handle different on tow? > Anything you'd care to share would be appreciated. They fly the same, except..... Acceleration. It is something if you have flown only those US made hot dog stands (2-33, 1-26 or similar). That's not an insult, just to describe the differences. With clean aerodynamics and laminar flow wings and weights over 525kg (1000lbs) they pick up speed very fast. This requires more attention on approach and also on tow. You have to keep airspeed even more precisely with nose attitude at the horizon. Airspeed indicators are slow, and even small changes in attitude cause significant changes in airspeed. This phenomenon has caused quite a few landing accidents all over the soaring nations. You need to think ahead more of the time than with 'trainers.' Momentum With clean aerodynamics and much weight they tend to keep the speed they gain. You can do pullups when entering a thermal and gain over 1500ft without circling in just 20 secs. That's when you notice it really that you fly high per. ship. You have to learn how to handle this momentum though. Controls ..are very responsive and usually light. This is something to remember when doing a high speed glide in good x-country day. You can easily fly at speeds higher than maneuvering speed, so easy on the controls. Glide Those things just go on and on. You have 50 miles home and 5000ft. Final glide computer says you are 200ft above glide slope. Interesting and unbelievable going on home with the sunset in dead air. Procedures Checklists are a must. You can't land, much less do outlandings, with extra weight, landing gear ought to be down, electrical vario has to be switched between glide and thermalling settings, wind corrections have to be programmed, navigate, communicate with ATC, constant decision making on weather development, ballast to carry and so on... I hope you get the picture. High performance ships are made for XC. They are fine to fly, but not for a beginner. Our club has two LS4a's and a DG-101 for so called competitive use. We require minimum 60 hrs for LS and 40 hrs for DG. Then minimum 20 landings on type before XC + instructor sign-off for simulated outlanding test. It is fairly small requirement, but we train in glass-ships here in Finland, so transition is easy, and our trainer is also glass, a polish Junior SZD-51. It is 34:1 ship, but slow. Oh one thing, we consider fiberglass and other fancy materials to be trivial. Also, as background info, we are lucky to have fairly young sailplane fleet in Finland for couple of reasons: 1 Tax and customs freedom for sailplanes. 2 Picking up glider in Germany, where most of the high perf. if not all are made, is fairly cheap compared to shipping them half-way around the world. 3 Reasonably big and wealthy clubs. Most of sailplanes are owned by clubs, not by individuals. Anything else???? Regards Matti Huoviala PP ASEL, CFIG, Towpilot, gopher.... ============================================================================ From: rmiller@i88.isc.com (Richard J. Miller) Subject: Re: QUESTION: Flying High Performance Gliders there may be a medium performance range of between 30 and 36, primarily to include the Blanik. the high perf break is usually defined by the low end of the standard class competition ships, which is currently about 38. the standard Libelle would run between 35 and 38 and has been the benchmark for many years. > Thinking about it some, all I could think of for differences is higher >speeds and retractable gear. Are there others? Are they "twitchier" to fly? >(Sorry for the technical terms.) Do they handle different on tow? > Anything you'd care to share would be appreciated. precision Most modern standard class ships (no flaps and 15 meter max span, we're talking Discus, LS-4, many DGs, Libelle, AS-W 19 and 24) are very docile. "Twitchy" can only be applied to these when the pilot hasn't figured out that the foot long throw that a 1-26 or Blanik needs on the stick in a thermal will roll you over on your back in a glass ship. It usually takes about 15 seconds to figure this out, but that usually happens just after the pilot lifts off on the first tow and gets into a nice PIO with the elevator. I have only seen one pilot transitioning to glass who didn't do that, and he had extensive time in an extremely short coupled acrobatic biplane. Be smooth and very conservative with the stick and you should have no trouble, you already had to learn this once when you figured out aerotow, now you just have to be more precise. That need for precision will also come into play when thermalling. You NEED to learn how to maintain pitch by watching the horizon, NOT by watching the air speed indicator BEFORE transition. If you can lock a spot on the canopy to the horizon and hold it all the way around, you won't have any problems. If you try to watch the speed, the lag in the gauge will have you hosed within a half turn. In terms of flying technique, your first problem in transitioning will be your reluctance to fly fast. The Discus, an admittedly very high performance standard ship (43:1), hits best glide at 60+ knots without water and 75 knots with full water. Those are numbers that will make you think you are really hot and sinking fast in most post solo ships. You DON'T cruise at best glide in glass. In reasonable weather, you cruise at 85 to 105 knots instead. Note that 105 is above red line for many 1-26s! You have to relearn flying speeds in a high perf ship. And almost anything with performance (negative) flaps are trickier. Modern 15 meter ships (flaps and 15 meter max span, AS-W 20, Ventus, LS-3 and 6, Mosquito, Mini-Nimbus) are still pretty docile, but they get marginal in slow flight turns (thermalling) much more quickly because of the thinner airfoils allowed by the flaps. The AS-W 20 has a known, very nasty thermalling stall characteristic. The Ventus needs to be flown continuously as it is very sensitive in pitch. The Glasflugel dive brake on the Mosquito, Mini-Nimbus, and Ventus needs to be seen to be believed and requires some careful instruction. Older ships, and especially first generation glass open ships (Diamante, AS-W 12, Open Cirrus, Phoebus), have their own unique (read that as nasty) handling problems that have only contributed to making the newer ships so nice to fly. I don't recommend using any of these for transition to glass. Same for ANY ship that has a drag chute. My Discus partner took the gear out of his old Phoebus the first time he tried the chute. Cost him 3 months of flying. Open ships (Nimbus 3, AS-W 22, AS-H 25)? he-he, in your dreams! Go find Moffat's "Winning on the Wind" and check out his thermalling technique for the big Nimbi that he flew (top rudder to tighten a turn, i kid you not!). Then remember that those monsters cost >$75K these days. Of course, they also hit better than 65:1 ... Rich Miller ex-Schempp-Hirth Discus JBX and ex-Rolladen-Schneider LS-4 TQ rmiller@i88.isc.com ============================================================================ ============================================================================ NET RESPONSES ============================================================================ From: jeffk@dosXX.med.utah.edu (Jeff Knell) Subject: Re: QUESTION: Flying High Performance Gliders From: donovanh@sptekwv1.wv.tek.com (Donovan Hammer;685-2499;60-850;;sptekwv1) Subject: Re: QUESTION: Flying High Performance Gliders From: petri@venus.iucf.indiana.edu (HOWARD PETRI) Subject: Re: QUESTION: Flying High Performance Gliders From: cohler@vxcrna.cern.ch (Mike Cohler) Subject: Re: QUESTION: Flying High Performance Gliders From: guy.byars@ssa.org (Guy Byars) Subject: RE: QUESTION: FLYING HIGH Tom Knauff, noted soaring instructor and author, gave a presentation at the SSA convention on beginning XC soaring. He was asked about transition to high-performance gliders and the primary differences between flying them and low-med performance ships. His first response was that the notion of high-p gliders being difficult to fly is a common myth, and that in many cases they are easier to fly than some of the low-med-p ships. There are, of course, some twitchy high-p ships and some that can bite you harder than others; for example, I've been told that a Ventus is more difficult to fly that an LS-6. It is my understanding that with 1-26 and 1-34 (or similar) time and proper respect and training one should have no trouble transitioning to a high-p glider. The primary caveat was the much faster acceleration of high-p ships. If you have a tendency to push on the stick when you feel high on approach, you could find yourself with a lot of speed to burn off. The other potential problem that I suppose most of us have heard is the tendency for PIOs due to the more sensitive controls (shorter stick travel). I hope someone with more experience than I will elaborate on this. Have fun, jeff ============================================================================ From: donovanh@sptekwv1.wv.tek.com (Donovan Hammer;685-2499;60-850;;sptekwv1) Subject: Re: QUESTION: Flying High Performance Gliders > Tom Knauff, noted soaring instructor and author, gave a presentation > at the SSA convention on beginning XC soaring. He was asked about > transition to high-performance gliders and the primary differences > between flying them and low-med performance ships. > > His first response was that the notion of high-p gliders being > difficult to fly is a common myth, and that in many cases they > are easier to fly than some of the low-med-p ships. I listened to Tom Knauff at the SSA convention and would agree with him up to a point. Actually he briefly acknowledged the point I'm going to make but unfortunately he went on without pressing it. When all is going well (ie, good weather, no distraction, etc.), most high performance gliders are no harder to fly than the medium performance. However, when things are not going well the more slippery high performance gliders can let things deteriorate more quickly than a higher drag low/medium performance glider. Also, the greater complexity of the cockpit can delay corrective action also. A good recent example of this that got a lot of press was the Piper Malibu (sp?). No problems until the combination of IMC and interior distractions caused a lapse in situational awareness. The Malibu could accelerate to red line more quickly than the pilots could react. Also the complexity of cockpit resources added to the pilot's confusion as the situations deteriorated. We had a similar accident with one of our club gliders that resulted when a fairly experienced pilot was placed into a new glider. One higher performance than he was used to. He launched to work a ridge in marginal weather. And furthermore he was relatively new to the area. What a set up! A combination of clouds and fogged canopy and lack of terrain familiarity resulted in spatial disorientation. He was new to the glider, and with the cockpit complexity and deteriorating situation, he was unable to find the air vent to unfog the canopy. The faster, more slippery glider certainly accelerated the rate that the situation deteriorated. The result was a spiral dive that ended with a crash that totaled glider. The pilot miraculously survived. I not saying that this could not have happened with a 1-26, but at least even a fairly new pilot can find the air vent. And speed doesn't build up quite as fast. -- Don Hammer ============================================================================ From: petri@venus.iucf.indiana.edu (HOWARD PETRI) Subject: Re: QUESTION: Flying High Performance Gliders I transitioned from a K13 to a K8 our K6 and then to a Std. Cirrus. I now own a Pegasus. I never found the glass ships that traumatic a change and would agree with Knauff--it isn't a big deal. One difference I did notice though. Some glass ships have very small rudders and one doesn't get rudder control until one gets some decent speed going. This can be hundreds of feet into the roll during which you are only a passenger. The moral is to have the ship pointed in the right direction to start with---or else!! It is also true that one may get very little or no buffet warning before a stall. This could be bad for the uninitiated while in the pattern. Otherwise the main difference are those long glides you can now make. I bought a glass bird and I am a satisfied customer. Howard Petri Pegasus (EJ) ============================================================================ From: cohler@vxcrna.cern.ch (Mike Cohler) Subject: Re: QUESTION: Flying High Performance Gliders I think that a god many points have already been mentioned..... here are my extra thoughts... often the higher performance machines have longer wings. When you are launching you need to make sure that you are ready to release the INSTANT that a launch starts to fail. Don't ever hang on in the hope that a swing to the left will correct itself, say. The long wing machines will often ground loop very readily if a wing drop only a little bit. Also transitioning to a "hot ship" often means transitioning to a machine with flaps. Get trained on a dual machine with flaps BEFORE jumping in to your new toy. Getting early aileron control on the launch and the change of flap setting during the ground run is often something that takes a little time to get used to. Get trained on the use of negative flap for high speed flight, and get used to the extra degree of freedom that flaps give you. Also getting to know EXACTLY which lever does the flap and which the airbrake is vital.... pulling the wrong one on approach to a small field could leave you a little embarrassed !! Get used to the ship's characteristic behavior... for example some glass ships don't sideslip very well... try sideslipping in a Janus and see what I mean ! All these things are watchpoints... of course you should explore the flight envelope and characteristics of any INDIVIDUAL aircraft very well before you can say you are familiar with it. I used to be told that you need at least 10 hours in a machine before you are even vaguely familiar with it. In easy conditions most machines are not a problem.. but it is when you get into marginal weather and are under pressure that your own skill and familiarity with a machine make the difference between making it down in one piece or not making it. I hope this helps. Mike ============================================================================ From: guy.byars@ssa.org (Guy Byars) Subject: RE: QUESTION: FLYING HIGH -> His first response was that the notion of high-p gliders being -> difficult to fly is a common myth, and that in many cases they -> are easier to fly than some of the low-med-p ships. There are, of Tom is right. My LS-4 is the easiest to fly and most stable of any airplane I have flown. -> course, some twitchy high-p ships and some that can bite you harder ASW-12 is probably the best example! -> The other potential problem that I suppose most of us have -> heard is the tendency for PIOs due to the more sensitive -> controls (shorter stick travel). I hope someone with more -> experience than I will elaborate on this. The 1-26 has a MUCH greater PIO tendency than the LS-4 because it is much more pitch sensitive. In short, the LS-4 is easier to fly than the 1-26. As far as picking up speed quickly, most high performance ships have VERY effective spoilers so that isn't really a problem Guy Ford Byars ============================================================================ From: rmiller@i88.isc.com (Richard J. Miller) Subject: Re: QUESTION: FLYING HIGH In article <621.1.uupcb@ssa.org> guy.byars@ssa.org (Guy Byars) writes: ... >-> course, some twitchy high-p ships and some that can bite you harder > >ASW-12 is probably the best example! You really know how to pick a NASTY example, 48:1 and NO spoilers and a drag chute (the B model had TWO drag chutes). Funny how there aren't many of these things left. But put one in the hands of someone who knows how to use it and wow! >-> The other potential problem that I suppose most of us have >-> heard is the tendency for PIOs due to the more sensitive >-> controls (shorter stick travel). I hope someone with more >-> experience than I will elaborate on this. > >The 1-26 has a MUCH greater PIO tendency than the LS-4 because it is >much more pitch sensitive. In short, the LS-4 is easier to fly than >the 1-26. All true, but before the 1-26 folk start arguing, make sure to consider the amount of throw in the stick. You can move a 1-26 stick a bunch and still not get as much pitch change as a short throw in a LS-4. I have only seen one person who was transitioning into a glass ship who did not have a pitch PIO just after lifting off on the first tow. He had extensive time in a short coupled biplane. It usually doesn't take long to get used to it, but it's better to be prepared because it's going to happen. >As far as picking up speed quickly, most high performance ships have >VERY effective spoilers so that isn't really a problem Something that a student coming from a 1-26 or other lower performance ship may not think about considering how weak some spoilers are. Rich Miller ex-Schempp-Hirth Discus JBX and ex-Rolladen-Schneider LS-4 TQ rmiller@i88.isc.com ============================================================================ From: cnj@lab.jt.dk (Claus N. Jacobsen) Subject: re: QUESTION: Flying High Performance Gliders A lot of good answers have already been given to this question. Being an instructor of a Danish gliding club where we often have to transfer our students from low performance one- and two-seaters to high performance glassfibre gliders I would like to contribute a little of our experience. In general most modern ships are much easier to handle than the older ones. That goes particularly for planes like LS 1f, LS 4, DG-300, SZD-51 Junior, ASK-23 and to a certain extent the Astir. However, they all differ from the low performance gliders in the fact that they have CG behind the main gear: Whereas low-p gliders tend to stay on the ground if you land them at too high airspeed, the modern ones tend to bounce. Some students panic when this happens and puts the stick forward resulting in a heavy landing, more bouncing, even harder landings and so forth until the main gear collapses. The Astir is particularly nasty in this respect, especially if you land it with little or no airbrakes extended. The way we make the transfer, is by training our students on a Twin Astir before letting them have a go on their first high-p single seat ship. This procedure has eliminated all the problems we used to encounter. The problem mentioned above is our only serious concern when transferring new people to modern ships. They are really much more gentle than the older ones. However, you should distinguish modern ships (such as the ones mentioned above) from first- and second generation glassfibre ships such as the Standard Libelle, Standard Cirrus, LS-1 (anything but the f-type), ASW-15 etc. Many new people tend to buy these ships because they are cheaply available, but they cause more problems than the newer ones. Some of them have very twitchy elevators (Std. Cirrus in particular), most have poor airbrakes and some have ailerons which are very insensitive at low airspeeds. This might cause you problems during take-off and landing. But once our students have a little experience with glassfibre performance on a Twin Astir or the like, they can usually overcome these problems. As for flapped gliders, we have some special experience, that I would like to share, if anyone is interested. Yours Claus Jacobsen Gliding Club of Aarhus, Denmark ============================================================================ From: jmmatthe@apgea.army.mil (Jeffrey M. Matthews ) Subject: Re: QUESTION: Flying High Performance Gliders I'll take a shot at this from the starting point of getting out of the ubiquitous 2-33/1-26 into other ships. My apologies to you Europeans and Southerners who don't see many Schweizers, and to you glass drivers who don't consider anything under 35:1 to be high performance. SPOILERS: The 2-33 has, by 1930's standards, excellent spoilers. However, there are many ships out there with terminal velocity dive brakes. In the 33 or 26, one can hold full spoiler from downwind to touchdown and still have speed in hand to flare without stalling or hitting the tail (Start a bit high if yer gonna do that). The descent rate will stabilize quickly at about 400-500 fpm. In, for example, the 2-32, at a normal pattern speed, the descent rate will keep on increasing until you're coming down at close to 2000 fpm (dozen year old memory, might be a bit off) and there is no way you can flare that away. Not that you can't use full spoiler in the pattern, but you gotta watch the descent rate, not just assume that because it was 500 fpm ten seconds ago, it's still 500. Of course, we all plan our patterns so that we can hold about 1/4 to 1/2 spoiler all the way, don't we? The need for full spoiler, or none, indicates a bit of misjudgment of either position or conditions. FLAPS: In transitioning from, say, the 2-32 to the 1-35, remember that the stalling speed is lower, not higher, when the drag producing equipment is extended. Many a first timer in a ship with 80 degree flaps has scooted two thirds of the way down the runway unable to plant the wheel due to the extra speed he's added because it's a "high performance" ship. Also, be aware that, unlike the 2-33 or 1-26, which need negligible pitch change to compensate for full spoiler, the slicker ships need definite stick/spoiler or stick/flap coordination. CROSSWIND TOLERANCE: Many of the slicker ships have minimal rudder in comparison to the trainers. In addition, unlike the Schweizers which just turn into the wind when they run out of rudder, many of the higher performance ships are taildraggers, and can do a real groundloop, often with damage to the aft fuselage when the tailwheel finally digs in. BALLAST: The addition of water to the wings makes the ailerons ineffective until a higher speed is achieved, and the momentum of the moving wing in yaw and roll can be surprising. Try to get a good sprinter to run the wing, and watch out for crosswinds. WEIGHT & BALANCE: Some higher performance ships are pickier about that than the Schweizer trainers. The 1-35, for example, has different limits for pilot weight with the seatback in the fore or aft position. Having said that, how 'bout another story? When I had just started towing, one of the "high performance" pilots on the field required "no less than 72 knots, and no more than 74", for his ship, while Ed Sessions asked me for "about 5 or 10 more than you'd use for a 2-33, but don't worry about it". The first guy was flying a 1-34, which is pleasant on tow at any speed above 55, and has an ASI calibrated in MPH. Ed was flying a PIK-20, which was one of the hottest ships in the air back then. 'Nother words, respect the difference, and investigate what to expect (which you've done) but don't let it over-impress you with itself or yourself. Enjoy Jeff Matthews Standard Disclaimers Apply =============================================================================== From: Rick Lafford Subject: Re: SUMMARY: Flying High Performance Gliders A friend just posted me a collected copy of this thread so I may be a bit late to respond. I thought that another opinion might help support some of what's been said. My background include a few hours towing and instructing in both gliders and ultralights. I started my 'glass' career in a Diamant HBV (15m) and am currently flying a Discus B. High performance (hp) means to me that the glider is capable of using any energy it has (altitude or airspeed) in a more effective, "high performance" manner. The term, when applied to gliders by glider pilots, typically doesn't refer to roll rates or other handling characteristics. I would support the comment that today's crop of hp gliders are very nice handling aircraft with no real vices. I would not hesitate to put any pilot with 20 safe and sane 1-34 flights in my Discus and have actually done just that. The manufacturers have really done a terrific job responding to needed design improvements on these gliders. With the early hp gliders, often the energy performance was not matched with other control systems such that you had a 45:1 glide with no good way to modulate or control the application of drag. While a chute or 90 degree flaps are great drag producers, they are difficult to modulate and the mechanism (drag increases w/airspeed) is not very obvious to the uninitiated. Today's ships have wonderfully effective dive brake/flap combinations which make energy management on approach very nice. High performance gliders are not really 'twitchier' to fly but because they have a wider operational airspeed range, the control response changes more. At liftoff speeds the ailerons are low effective but the elevator is quite effective due the requirement that you have good control of pitch elevated 'g' loadings and low airspeeds while thermalling. When cruising at speed, the ailerons are much more effective but the airloads balance nicely such that the force required to move the stick also increases. On tow, the 1-26 is in the mid-range of it's operational airspeed range and so has very quick roll and pitch rates. I know it certainly can change both pitch and roll more quickly than my Discus at 55 mph. So, which is 'twitchier'? It's all in the perspective. High performance gliders do take lots of experience to apply effectively. While putting a 50hr. pilot into an LS-6 may improve their ability to accumulate hours, it will not in itself make them a better cross-country pilot. Judging glides is particularly difficult in a 40:1+ machine unless you have experience or a computer, manual or electronic. Literally everything you can see, you can reach, but initially your mind will not accept that and you'll fly far too slowly and end up quite high at your goal. This is for the most part, quite safe for the pilot, much better than tending to push on because you're flying "a high performance glider" with a low performance mind. Because of their greater mass (when compared to a 1-34, KA-6 etc.) landing rolls tend to be longer. Modern dive brakes/flaps will get you over the trees and into the field nicely but the landing roll from a 55mph approach will be greater then the typical 40mph speed of a 1-26. This needs to be considered but I've found in training and by personal experience, that most pilots pick quite large fields anyway. The exceptions are usually those picked from too low and altitude at the last minute and that's a judgment issue for you to be aware of. An 800' 2-33 pattern would be flown at 400' in the Discus so the angle on the field is quite different. No problem with starting out with an 800' pattern, just that flying lower is no problem and gives you a much better look at the surface you're planning to land on. I hope I haven't muddied the water and thank Tony for asking a good question. I wish all glider pilots had access to machines like the Discus and LS-4/6 type aircraft. It is really quite a thrill and not beyond the skills of any attentive pilot. One parting shot... get a good cockpit briefing, sit in it until you can find everything critical while blindfolded, don't fly without a gear warning system (maybe leave it down and locked for the first flight) and put all the critical speeds on a post-it note stuck to the panel. Regards, Rick ------------------------------------------------------------------------------ Rick Lafford |Discus B, N154RS (HS) Rochester Soaring Club |Kolb Twinstar Mk II, N93RD lafford@clpd.kodak.com |ex. Diamant HBV, N11HS =============================================================================