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#1
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Flaps and V-Tails of Death
Hi all,
I'm here to report that I cheated death and survived a flight in a glider with the dreaded "Landing Flaps and V-Tails of Death". Jim Harper graciously allowed me to fly his beautiful HP-16. What's an HP-16 you say? Well, looks to be just like the HP-18 (or I should say the HP-18 is just like the -16) except that the -16 has a large and comfortable all metal cockpit instead of the narrow composite cockpit of the -18. Jim's -16 is equipped with winglets and, as far as I know, the ailerons are standard (not with the J.D. Colling mod, correct me if I'm wrong Jim). Center stick. Tow was behind our 180hp Cessna 175 on a 275 foot long rope. Started out in -2 flap position, went to + 5 at 40 knots. Had no trouble keeping the wings level. The bird lifted off level and was easy to fly on tow. Released and tried slow flight (no stalls), flight up to 90 knots. Steep turns, etc. Well sealed and quiet. Good rudder response and easy to coordinate compared to my 301 Libelle. More stable in a thermal than my Libelle. Aileron response was a little slower than my Libelle at thermaling speeds, but was positive and more than adequate for centering thermals. Climbed a few hundred feet in a very week thermal. Very nice thermalling glider. Landing was the best part. I stayed high and close in the pattern. I rolled on some flap on downwind, maybe 30 degrees or so. I was way high on final so I started rolling in more flaps. I never quite got to the full 90 degrees mark as I had the nose down at a truly obscene angle just to maintain 50 knots. Steeper than my 301 with the tailchute and full divebrakes. Steeper than a Mosquito with everything hanging out. This was more like parachuting than flying. Nothing but dirt out the front of the canopy. The horizon was visible more towards the top of the canopy. I aimed at a target and just kept the nose pointed there. I pulled back on the stick when I ran out of nerve. The bird settled on with a slight bump of the tailwheel and a little bounce as the main dropped on (I flared just a bit too much). I have no doubt that I could easily put this bird in a tiny field much easier than I could my Libelle (and that is not difficult at all). So, I'd have to say that all the bad things I've been told about landing flaps on gliders and V-tails are definitely untrue with respect to the HP-16. It is a comfortable and easy to fly glider and compares very well to my Libelle and also to other glass birds, including my favorites for handling, the Mosquito and LS-4. |
#2
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Wallace Berry wrote:
So, I'd have to say that all the bad things I've been told about landing flaps on gliders and V-tails are definitely untrue with respect to the HP-16. If you believe that, perhaps you haven't been told "all the bad things". For example, I've had HP pilots tell me getting sucked up into a cloud can be "awkward" to deal with when all you've got is flaps. My first and only flight in an HP went like Mr. Berry's; even so, I hope anyone beginning to fly a flaps only glider gets thorough checkout, because there are ways to go wrong. -- ----- Replace "SPAM" with "charter" to email me directly Eric Greenwell Washington State USA |
#3
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"Eric Greenwell" wrote in message
Wallace Berry wrote: So, I'd have to say that all the bad things I've been told about landing flaps on gliders and V-tails are definitely untrue with respect to the HP-16. If you believe that, perhaps you haven't been told "all the bad things". For example, I've had HP pilots tell me getting sucked up into a cloud can be "awkward" to deal with when all you've got is flaps. My first and only flight in an HP went like Mr. Berry's; even so, I hope anyone beginning to fly a flaps only glider gets thorough checkout, because there are ways to go wrong. No offense, Eric, but speaking from the vantage point of one with all his 1-26 glide-ratio time in flaps-only ships (C-70, HP-14, Zuni), the more powerful the flaps, the _less_ 'exciting' it need be if you allow yourself to get sucked into a cloud. (For those unfamiliar with lift in the western U.S., streets miles long and wide containing lift exceeding 10 knots are not uncommon, and 'getting sucked into a cloud' _can_ happen, even if relatively savvy and switched on...scale effects, new experience learning curves, etc.) Can we take as a given that what's 'thrilling' about IFR flight with a VFR panel is the very real possibility of pulling wings off in the ensuing spiral dive? If that's true, then the more drag you have available...and flapped HP's tend to have a LOT of disposable drag [a great thing as Wallace B. better understands now, :-)]...the less thrilling blind flight. My HP-14 wouldn't exceed 55 knots (as I recall) with full flaps when left to its own (hands-off) devices for minutes on-end. Sure, it took on some interesting attitudes as it alternately nosed up, stalled, fell off on a wing, regained speed, nosed up...etc., but there was no way it was ever going to come close to maneuvering speed. To avoid the repeated stalling, all one needed to do was hold 40 knots with full flaps (required forward stick). You'd eventually end up in a steep spiral, but, so what? My Zuni is less forgiving (considerably weaker flaps...i.e. less drag than the HP-14) in this regard, and will pretty soon exceed 75 knots hands-off-the-stick in the zoom, stall, fall off sequence, but like the HP is utterly innocuous if trimmed aft w. full flaps and held at 40 (or 45 or whatever one is comfortable with). Again, you're likely to eventually end up in a tight spiral if using this technique, but you're not going to pull the wings off. IMHO, playing imaginary mind games (and backed up by considerable experimentation over the years), my personal adrenaline level will be a lot lower in a flaps-only ship having 'adequate drag' (and I know of no 15-meter flap-only ships that do not) than in a spoilers-only ship if I envision being in a big, turbulent cloud with a VFR panel. For the record, I'm aware of the 'benign spiral mode.' Actually, I suspect 'flapped cloud safety' comes not so much the flaps as-such, but from their high level of drag. Imagine a tail-chute-only of 'ridiculously large diameter' to see what I mean...likewise, 'ridiculously large spoilers'. For non-U.S. pilots, the most powerful spoiler-only gliders I know of are the Schweizer 1-34 and 2-32, both of which have terminal-velocity-limiting dive brakes. Personally, I'd much rather come out the bottom of a cloud doing 40 knots in a spiral than at Vne more or less vertically. Adrenaline may have its place in the human condition, but I prefer to keep mine out of the cockpit! Regards, Bob - you can't have too much disposable drag - Whelan --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.538 / Virus Database: 333 - Release Date: 11/10/2003 |
#4
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Bob Whelan wrote:
"Eric Greenwell" wrote in message Wallace Berry wrote: So, I'd have to say that all the bad things I've been told about landing flaps on gliders and V-tails are definitely untrue with respect to the HP-16. If you believe that, perhaps you haven't been told "all the bad things". For example, I've had HP pilots tell me getting sucked up into a cloud can be "awkward" to deal with when all you've got is flaps. My first and only flight in an HP went like Mr. Berry's; even so, I hope anyone beginning to fly a flaps only glider gets thorough checkout, because there are ways to go wrong. No offense, Eric, but speaking from the vantage point of one with all his 1-26 glide-ratio time in flaps-only ships (C-70, HP-14, Zuni), the more powerful the flaps, the _less_ 'exciting' it need be if you allow yourself to get sucked into a cloud. The situations described to me were the difficulty of avoiding the cloud entry in the first place. A pilot can open his spoilers at 90 knots and begin descending immediately, but deploying the flaps at 90 knots first increases your altitude, making it much harder to stay out of the cloud. If you do lose control in a cloud, lots of drag is an advantage. The main point I hoped to make is landings aren't the only way spoilers and glide path flap operation differs, and one good landing isn't enough to know the pitfalls, even for landings. I think everyone agrees the HP series is a great ship to make off-field landings in the hands of a good pilot. -- ----- Replace "SPAM" with "charter" to email me directly Eric Greenwell Washington State USA |
#5
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Eric Greenwell originally replied...
If you believe that, perhaps you haven't been told "all the bad things". For example, I've had HP pilots tell me getting sucked up into a cloud can be "awkward" to deal with when all you've got is flaps. My first and only flight in an HP went like Mr. Berry's; even so, I hope anyone beginning to fly a flaps only glider gets thorough checkout, because there are ways to go wrong. Bob Whelan followed with... No offense, Eric, but speaking from the vantage point of one with all his (greater-than) 1-26 glide-ratio time in flaps-only ships (C-70, HP-14, Zuni), the more powerful the flaps, the _less_ 'exciting' it need be if you allow yourself to get sucked into a cloud. Eric G. further replied... The situations described to me were the difficulty of avoiding the cloud entry in the first place. A pilot can open his spoilers at 90 knots and begin descending immediately, but deploying the flaps at 90 knots first increases your altitude, making it much harder to stay out of the cloud. If you do lose control in a cloud, lots of drag is an advantage. The main point I hoped to make is landings aren't the only way spoilers and glide path flap operation differs, and one good landing isn't enough to know the pitfalls, even for landings. I think everyone agrees the HP series is a great ship to make off-field landings in the hands of a good pilot. I figured there was some nuance I was missing. No harm no foul. I agree with all your points. For my part I just wanted to throw out for general consideration that though flaps ARE different than spoilers, 'different' doesn't necessarily strongly equate with 'bad.' Nor does 'different' necessarily strongly equate with 'large cojones.' Free information is always worth every cent paid for it, but (in my flap-biased view) there seems to be more misleading/'flaps are bad' information floating around about flaps than there is of the sort to be found in this particular thread...which thus far contains accurate - if necessarily incomplete - information in every post. Just to provide a counterpoint to your scenario of avoiding the cloud in the first place (always a good idea, if not always achieved), it's worth pondering how ANYone comes to the decision s/he may require imminent cloud avoidance techniques. Consider the particular case of a powerful western U.S. cloud street. Odds are J. Pilot will be cruising along at 80+ mph and suddenly have a "HolyCOW!' moment upon realizing cloud avoidance is necessary. Options likely to spring to the surprised mind?: 1) course change; 2) nosing over/adding energy; 3) adding gear drag; 4) adding flap/spoiler drag. All will be exciting in a suddenly more thrill-filled cockpit. I've spoken to 2 pilots (years apart) soon after each first intentionally opened spoilers at above-pattern speeds, one in a St'd Cirrus near 120 knots trying to get below a finish gate in a regionals, and the other in an Astir-CS trying to avoid being sucked into a big, wide, western cloudstreet who had options 1, 2, & 3 prove insufficient. We laughed about things because we were on the ground, but they were both wide-eyed recollecting the BIG negative G event occasioned by opening spoilers at higher-than-pattern-speeds, even though both had time to realize prior to pulling the spoiler handle they were treading in new (for them, at the times) territory. Playing Joe Test Pilot is always best done (IMHO) under more controlled conditions than 'needing' to play JTP. FWIW, I thought the St'd Cirrus pilot did by far the more foolish thing...because he took an avoidable risk, whereas the Astir CS pilot felt he had no other choice. Both whanged their heads on the canopy. The Astir pilot wound up in a high-speed, gear-down, spoilers-out slip trying desperately to stay out of the cloud street. About the time he could see he was going to be successful avoiding the cloud, he heard a radio call to the effect, "Glider at XXX over YYY, this is Cessna ZZZ. Are you OK?" Being at XXX over YYY, he declined to answer (would've required a 3rd hand w/o a boom mic), though afterwards he could appreciate a certain irony in the situation! Regards, Bob W. --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.538 / Virus Database: 333 - Release Date: 11/10/2003 |
#6
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From: Eric Greenwell
If you believe that, perhaps you haven't been told "all the bad things". For example, I've had HP pilots tell me getting sucked up into a cloud can be "awkward" to deal with when all you've got is flaps. "all the bad things"? Do go on, Eric. I fly an RS-15 and I don't worry about spoiler(s) not being connected or accidentally opening. There are some very positive things about the HPs. Also, when landing flaps are deployed the ship becomes incredibly stable and the stall speed decreases. That's a nice feeling when down low. My first and only flight in an HP went like Mr. Berry's; even so, I hope anyone beginning to fly a flaps only glider gets thorough checkout, because there are ways to go wrong. As with any ship that is "new in type" to the pilot. But good advice. Regards, -Doug |
#7
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Here are some pictures of Jim Harper's HP-16:
http://www.soaridaho.com/Schreder/HP...rst_Flight.htm Wayne http://www.soaridaho.com/ "Wallace Berry" wrote in message ... Hi all, I'm here to report that I cheated death and survived a flight in a glider with the dreaded "Landing Flaps and V-Tails of Death". Jim Harper graciously allowed me to fly his beautiful HP-16. What's an HP-16 you say? Well, looks to be just like the HP-18 (or I should say the HP-18 is just like the -16) except that the -16 has a large and comfortable all metal cockpit instead of the narrow composite cockpit of the -18. Jim's -16 is equipped with winglets and, as far as I know, the ailerons are standard (not with the J.D. Colling mod, correct me if I'm wrong Jim). Center stick. Tow was behind our 180hp Cessna 175 on a 275 foot long rope. Started out in -2 flap position, went to + 5 at 40 knots. Had no trouble keeping the wings level. The bird lifted off level and was easy to fly on tow. Released and tried slow flight (no stalls), flight up to 90 knots. Steep turns, etc. Well sealed and quiet. Good rudder response and easy to coordinate compared to my 301 Libelle. More stable in a thermal than my Libelle. Aileron response was a little slower than my Libelle at thermaling speeds, but was positive and more than adequate for centering thermals. Climbed a few hundred feet in a very week thermal. Very nice thermalling glider. Landing was the best part. I stayed high and close in the pattern. I rolled on some flap on downwind, maybe 30 degrees or so. I was way high on final so I started rolling in more flaps. I never quite got to the full 90 degrees mark as I had the nose down at a truly obscene angle just to maintain 50 knots. Steeper than my 301 with the tailchute and full divebrakes. Steeper than a Mosquito with everything hanging out. This was more like parachuting than flying. Nothing but dirt out the front of the canopy. The horizon was visible more towards the top of the canopy. I aimed at a target and just kept the nose pointed there. I pulled back on the stick when I ran out of nerve. The bird settled on with a slight bump of the tailwheel and a little bounce as the main dropped on (I flared just a bit too much). I have no doubt that I could easily put this bird in a tiny field much easier than I could my Libelle (and that is not difficult at all). So, I'd have to say that all the bad things I've been told about landing flaps on gliders and V-tails are definitely untrue with respect to the HP-16. It is a comfortable and easy to fly glider and compares very well to my Libelle and also to other glass birds, including my favorites for handling, the Mosquito and LS-4. |
#8
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The situations described to me were the difficulty of avoiding the cloud entry in the first place. A pilot can open his spoilers at 90 knots and begin descending immediately, but deploying the flaps at 90 knots first increases your altitude, making it much harder to stay out of the cloud. If you do lose control in a cloud, lots of drag is an advantage. The main point I hoped to make is landings aren't the only way spoilers and glide path flap operation differs, and one good landing isn't enough to know the pitfalls, even for landings. I think everyone agrees the HP series is a great ship to make off-field landings in the hands of a good pilot. -- ----- Replace "SPAM" with "charter" to email me directly Eric Greenwell Washington State USA Eric. Good points.... But flap deployment at speed needn't cause an altitude change. Roll 40 or so your favorite direction, g up and put them out. Minimal altitude gain if any. Scott. |
#9
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Scott remember Eric speaks for the little old lady division of the SSA.
Winter is here let the fun begin. Al "Scott Correa" wrote in message ... The situations described to me were the difficulty of avoiding the cloud entry in the first place. A pilot can open his spoilers at 90 knots and begin descending immediately, but deploying the flaps at 90 knots first increases your altitude, making it much harder to stay out of the cloud. If you do lose control in a cloud, lots of drag is an advantage. The main point I hoped to make is landings aren't the only way spoilers and glide path flap operation differs, and one good landing isn't enough to know the pitfalls, even for landings. I think everyone agrees the HP series is a great ship to make off-field landings in the hands of a good pilot. -- ----- Replace "SPAM" with "charter" to email me directly Eric Greenwell Washington State USA Eric. Good points.... But flap deployment at speed needn't cause an altitude change. Roll 40 or so your favorite direction, g up and put them out. Minimal altitude gain if any. Scott. |
#10
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In article ,
Eric Greenwell wrote: Wallace Berry wrote: So, I'd have to say that all the bad things I've been told about landing flaps on gliders and V-tails are definitely untrue with respect to the HP-16. If you believe that, perhaps you haven't been told "all the bad things". For example, I've had HP pilots tell me getting sucked up into a cloud can be "awkward" to deal with when all you've got is flaps. My first and only flight in an HP went like Mr. Berry's; even so, I hope anyone beginning to fly a flaps only glider gets thorough checkout, because there are ways to go wrong. No doubt there are ways to go wrong, but every design has it's quirks. I would sooner turn a low time pilot loose in that HP-16 than my 301 Libelle. For sure my one experience in a landing flapped equipped bird is far too little experience to generalize. That's why I limited my comments to the HP-16. However, I have been told horror stories about V-tails and landing flaps. You know the stories. I was told the V-tail HP's were hard to fly and dangerous for any but the most experienced fliers. I'm no ace but I thought the thing was very easy to fly. Maybe the other HP's are different. The main myth is that you can't modulate the flaps to control glide path. In the HP-16, I rolled the flaps on and off within a fairly wide range and the glider behaved very much like a glider with very effective divebrakes. I would be very comfortable landing Jim's HP-16 in any reasonably landable field. Deploying flaps at high speeds can be problematic in a number of ships. I have heard that at least one 301 Libelle structural failure was due to flap deployment at a speed significantly above Vne. However, a number of ships which have flaps that deploy with the divebrakes have maximum deployment speed limitations too. And, not to forget, deployment of just divebrakes at high speeds can be dangerous. I think a couple of open class ships have lost their wings when the divebrakes were deployed well over Vne. As for getting sucked into a cloud, I would have an easier time keeping that HP-16 out of the cloud than my Libelle with it's relatively ineffective divebrakes. I have been in the gear down, full divebrakes and full slip configuration diving for the edge of the cloud at high speed to keep from getting sucked in. Fly safe, Wallace |
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