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#21
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Hi All,
I have a 1/5 share in a 1-35 here in Alaska. I find this glider a delight to fly and the flaps seem to work just fine for approach control. Once at 30 degrees I can modulate between 30 degs and full without much trouble just as I do with spoilers. The nose needs to be pointed down when adding flaps and this is quite normal in any aircraft with flaps that I have flown. I am amazed at how small an area this glider will land in. And again how far it will float at flaps 30. Seems like it has great spot landing control. If one is a first timer with flap use there might be a learning curve that could best be handled with some dual time in a Cessna practicing some power off landings. (I love the older Cessnas with the manual flaps) Jeff Banks N2JY |
#22
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Maule Driver wrote:
But I've landed in extremely gusty/wind shear conditions on several occassions. That is, with T-storms over or on the airport (stupid? Yes.) Flying with spoilers and flaps saved the day. Upon reflection if given a choice between the 2, it would have to be spoilers. In those admittedly extreme conditions, airspeed excursions are not entirely in one's control and spoilers-only are better than flaps-only no matter the level of pilot proficiency. A couple HP owners told me that spoilers are preferable to flaps when flying fast under clouds with strong lift: * if the lift suddenly increases and threatens to suck you into the cloud, spoilers can be quickly deployed keep you below the cloud. * flaps will first increase the lift as you begin to lower them, and take you into the cloud. Increasing speed to stay out of the cloud may put you over the speed limit for the flap setting you need avoid the cloud. Have other HP owners encountered this situation, and how do they cope with it? -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
#23
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I've never flown an HP. Getting sucked into a cloud seems to primarily
be a strong conditions (e.g. Western US) problem. Happened to me in an LS6... have no idea what I'd do with a flaps-only ship except exceed redline. Deploying the spoilers at close to redline scared the stuff out of me as it was, but it worked. Eric Greenwell wrote: A couple HP owners told me that spoilers are preferable to flaps when flying fast under clouds with strong lift: * if the lift suddenly increases and threatens to suck you into the cloud, spoilers can be quickly deployed keep you below the cloud. * flaps will first increase the lift as you begin to lower them, and take you into the cloud. Increasing speed to stay out of the cloud may put you over the speed limit for the flap setting you need avoid the cloud. Have other HP owners encountered this situation, and how do they cope with it? |
#24
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"Maule Driver" wrote ...
I've never flown an HP. Getting sucked into a cloud seems to primarily be a strong conditions (e.g. Western US) problem. Happened to me in an LS6... have no idea what I'd do with a flaps-only ship except exceed redline. Deploying the spoilers at close to redline scared the stuff out of me as it was, but it worked. Eric Greenwell wrote: A couple HP owners told me that spoilers are preferable to flaps when flying fast under clouds with strong lift: * if the lift suddenly increases and threatens to suck you into the cloud, spoilers can be quickly deployed keep you below the cloud. * flaps will first increase the lift as you begin to lower them, and take you into the cloud. Increasing speed to stay out of the cloud may put you over the speed limit for the flap setting you need avoid the cloud. Have other HP owners encountered this situation, and how do they cope with it? Having flown an HP-14 for 195 hours and a much-weenier-flapped Zuni for several thousand, all of it out west, and having in both been concerned about getting sucked into strong cloud streets, here's what I did: 1) immediately slowed down (to some speed below which full flaps could easily/safely be put down); 2) put down full flaps; 3) changed course to the nearest cloud edge. 4) gave thanks I was flying a flapped ship! Low stress, structurally safe. Even if one was so foolish/bold/situationally-unaware as to go into the cloud immediately upon the pull-up to slow down, who among us canNOT simply provide a stick input until the stall, prior to losing control in the cloud? If a pilot can do that, s/he can put down the flaps after the speed bleeds down. (Individual mileage may vary. Not approved by the Insurance Institute of America or the American Bar Association.) Short of having the magic fairy wave a magic wand, I've a hard time imagining anything simpler and safer in glider/cloud-avoidance terms. If - for the sake of limiting this discussion - we ignore *how* one comes to be in the situation of realizing cloud avoidance is (thought to be) a necessity, and consider only the (forced) choices of either a) opening spoilers at high speed for the first time beneath a cloud AND successfully staying out of said cloud (e.g. Maule Driver!), or b) pulling on full flaps at low speed AND unsuccessfully NOT staying out of said cloud (not me!), the coward in me opts for "b)" in a heartbeat. Even with the Zuni's wimpy large-deflection flaps, there is ZERO risk of exceeding maneuvering speed and pulling the wings off in a spiral dive, because one must *hold* forward stick w. full flaps to maintain flying speed. And, yes, the above was tested and incorporated in a plan long before needing it in both ships... Regards, Bob - gliders can never have too much disposable drag - W. |
#25
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At 21:36 19 August 2005, Bob Whelan wrote:
Having flown an HP-14 for 195 hours and a much-weenier-flapped Zuni for several thousand, all of it out west, and having in both been concerned about getting sucked into strong cloud streets, here's what I did: 1) immediately slowed down (to some speed below which full flaps could easily/safely be put down); 2) put down full flaps; 3) changed course to the nearest cloud edge. 4) gave thanks I was flying a flapped ship! Low stress, structurally safe. Even if one was so foolish/bold/situationally-unaware as to go into the cloud immediately upon the pull-up to slow down, who among us canNOT simply provide a stick input until the stall, prior to losing control in the cloud? If a pilot can do that, s/he can put down the flaps after the speed bleeds down. (Individual mileage may vary. Not approved by the Insurance Institute of America or the American Bar Association.) It would be a lot easier with airbrakes - just open them. |
#26
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I have not encountered a situation where this would be an issue near the
clouds. I would just speed up. I would not mind having spoilers on occasions, when it is necessary to insert one self into a pattern after many gliders return at the same time in a contest setting. Even then when I am finally committed to land after I have given way because I was not able to quickly get into on opening. The landings are most civilized even if some one is worse off then I in terms of squeezing in there is always enough space for gliders to land. One does not always have to land near the trailer. Regards Udo |
#27
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"Udo Rumpf" wrote in message ... I have not encountered a situation where this would be an issue near the clouds. I would just speed up. I would not mind having spoilers on occasions, when it is necessary to insert one self into a pattern after many gliders return at the same time in a contest setting. Even then when I am finally committed to land after I have given way because I was not able to quickly get into on opening. The landings are most civilized even if some one is worse off then I in terms of squeezing in there is always enough space for gliders to land. One does not always have to land near the trailer. Regards Udo This whole thread says a lot about glider flight training. Airplane pilots are trained with flaps so they are comfortable with them. Glider pilots are trained with spoilers, since there are no flapped trainers, so that's what they are mostly comfortable with. In fact, a skilled pilot can handle any situation with either. If there's a situation where a pilot feels uncomfortable, talking with an instructor skilled in flapped gliders is advisable. (ASK first whether the instructor has any time in a flap-only glider.) I have flown both and, although most of my experience is in spoiler equipped gliders, I prefer flaps for all the reasons the pro-flap folks have listed. I'll add another. Spoilers, even when closed, disrupt the upper wing surface in the most critical area - flap only wings are cleaner. Bill Daniels |
#28
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Bill Daniels wrote:
Spoilers, even when closed, disrupt the upper wing surface in the most critical area - flap only wings are cleaner. And yet, on a well built glider, you can carefully smooth and seal the spoilers so there is no leakage or surface unevenness, test the glider, and it isn't any better. My recollection from Johnson's tests is the most critical area on the wing is the first few inches of the nose (bug problems), and that the boundary layer is thick enough at the spoilers that they do not affect the flow on the typical racing glider. One might also consider how much "disruption" in air flow a Holighaus or Waibel would tolerate! Even if I'm right about the airflow disruption, it doesn't negate the principal advantages of flaps, but I think most pilots would prefer a combination of the two. There may also be performance issues related to designing a modern flap only glider: because modern airfoils use such narrow control surfaces, a flap only glider might not have enough glide path control. I was astonished at the difference in glide angle between my ASW 20 and my ASH 26 E, even though they employ the same flap system for landing: the ASW 20 descended much more steeply than does my ASH 26. Even though part of that is likely due to the higher wing loading on the 26, the flap chord on the 20 is almost double that on the 26. -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
#29
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Eric Greenwell wrote: Bill Daniels wrote: Spoilers, even when closed, disrupt the upper wing surface in the most critical area - flap only wings are cleaner. And yet, on a well built glider, you can carefully smooth and seal the spoilers so there is no leakage or surface unevenness, test the glider, and it isn't any better. My recollection from Johnson's tests is the most critical area on the wing is the first few inches of the nose (bug problems), and that the boundary layer is thick enough at the spoilers that they do not affect the flow on the typical racing glider. One might also consider how much "disruption" in air flow a Holighaus or Waibel would tolerate! Even if I'm right about the airflow disruption, it doesn't negate the principal advantages of flaps, but I think most pilots would prefer a combination of the two. There may also be performance issues related to designing a modern flap only glider: because modern airfoils use such narrow control surfaces, a flap only glider might not have enough glide path control. I was astonished at the difference in glide angle between my ASW 20 and my ASH 26 E, even though they employ the same flap system for landing: the ASW 20 descended much more steeply than does my ASH 26. Even though part of that is likely due to the higher wing loading on the 26, the flap chord on the 20 is almost double that on the 26. -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA True, I am building a new wing and I was hoping to include landing flaps only. The airfoil was not given me the results I desired with the larger flaps. I had to reduce the flap size to 16% and install spoilers. The flap/aileron arrangement will similar to the DG800, May real preference would be the ASW20/26/27 set-up but I decided to keep it simple As for surface aerodynamics the spoilers are always past the laminar transition. Smooth and sealed spoiler boxes have no ill effect. In my case the max transition on the top surface will be at 66% and that is where the box will be installed. Regards Udo |
#30
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One question for 'flaps only' glider drivers:
On a cross country aero tow, do you ever feel a need for some type of draggy things to help keep you in tow position? If you need a tow speed fast enough to get you home before the sun sets but that makes it too fast to deploy flaps, what procedure do you use, if and when necessary, to keep the towrope tight? Yea, yea, yea, I know: Fly it properly and you won't need to worry. But what about when the tuggie snoozes a little and starts a slight descent and gains speed. (Hey, I'm not even sure spoilers could help out here.) Popping spoilers out sure works nicely and easily. And by the way, I don't like cross-country aerotows. Sometimes, I think I would rather have the trailer instead of the towplane. Ray Lovinggood Carrboro, North Carolina, USA LS1-d (No flaps. Spoilers only) |
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