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#11
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To prevent wing drop in Libelles:
Longer tow rope. 250-300 feet works well. Start with open divebrakes on the 201 during the initial roll. But, be very careful here. The Libelle's brakes aren't very powerful which makes a brakes open on tow problem especially insidious. If they are open after lift off, the tug driver probably won't notice immediately. You will be way down the runway when you and the tuggy realize that something is wrong. Take it from one who knows ; )! Use negative flap on the 301. Works even better than opening the divebrakes on the 201 and doesn't have the inherent hazard of open brakes on tow. Stick full forward from the beginning of the takeoff roll until the tail comes up. This will get you aileron authority as quickly as possible. My 301 has Kestrel landing gear which is even taller than the original 301 gear. This makes for an even greater potential for wing drop. Using the above techniques, I rarely ever have a wing drop, even when being towed by weak tugs. -- Take out the airplane for reply |
#12
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Wallace Berry wrote:
To prevent wing drop in Libelles: snip Stick full forward from the beginning of the takeoff roll until the tail comes up. This will get you aileron authority as quickly as possible. I suggst that this is not good practice in a cross-wind takeoff, where you want the tail wheel firmly on the ground to help keep the glider straight. It is probably not necessary in any case: by the time you are going fast enough to lift the tail, aren't the ailerons already so effective you won't drop a wing? -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
#13
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In article ,
Eric Greenwell wrote: Wallace Berry wrote: To prevent wing drop in Libelles: snip Stick full forward from the beginning of the takeoff roll until the tail comes up. This will get you aileron authority as quickly as possible. I suggst that this is not good practice in a cross-wind takeoff, where you want the tail wheel firmly on the ground to help keep the glider straight. It is probably not necessary in any case: by the time you are going fast enough to lift the tail, aren't the ailerons already so effective you won't drop a wing? What you state is exactly what I would expect. But, for whatever reason, holding forward stick on my 301 seems to help significantly with avoiding a wing drop. Even with the stick forward, the rudder is effective before the tail comes up. So far, no problems with cross wind take offs, which they nearly all are at our site. One thing I forgot to mention, my Libelle only has the CG hook, the nose hook having been glassed over by a previous owner. Because of this, the tail on my 301 tends to stay down a bit longer than one being towed by the nose hook. With a long rope, negative flap and the stick forward, I've done unassisted takeoffs with no trouble. Haven't tried that with a strong crosswind. -- Take out the airplane for reply |
#14
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Wallace Berry wrote:
In article , Eric Greenwell wrote: Wallace Berry wrote: To prevent wing drop in Libelles: snip Stick full forward from the beginning of the takeoff roll until the tail comes up. This will get you aileron authority as quickly as possible. I suggst that this is not good practice in a cross-wind takeoff, where you want the tail wheel firmly on the ground to help keep the glider straight. It is probably not necessary in any case: by the time you are going fast enough to lift the tail, aren't the ailerons already so effective you won't drop a wing? What you state is exactly what I would expect. But, for whatever reason, holding forward stick on my 301 seems to help significantly with avoiding a wing drop. Even with the stick forward, the rudder is effective before the tail comes up. So far, no problems with cross wind take offs, which they nearly all are at our site. One thing I forgot to mention, my Libelle only has the CG hook, the nose hook having been glassed over by a previous owner. Because of this, the tail on my 301 tends to stay down a bit longer than one being towed by the nose hook. With a long rope, negative flap and the stick forward, I've done unassisted takeoffs with no trouble. Haven't tried that with a strong crosswind. I got confused about who was flying what, and my comments were intended for a 201. My 301 didn't drop a wing as long as I started in full negative flap. It's been 20 years, but I think I used some back stick at the start. Mine did have the nose hook. -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
#15
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"Wallace Berry" wrote in message One thing I forgot to mention, my Libelle only has the CG hook, the nose hook having been glassed over by a previous owner. Because of this, the tail on my 301 tends to stay down a bit longer than one being towed by the nose hook. With a long rope, negative flap and the stick forward, I've done unassisted takeoffs with no trouble. Haven't tried that with a strong crosswind. Using the nose hook will reduce the tendancy for wing drops. Bob Salvo |
#16
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"Bob Salvo" wrote in message ... Using the nose hook will reduce the tendancy for wing drops. Bob Salvo Really? Why? Bill Daniels |
#17
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Bill,
Not sure, but when I sealed over my nose hook on the H301 and used the CG hook for aertow, I had more trouble keeping a wing from dropping. I think when the CG hook is used and there is a wind gust from the side at the start of launch, there is more tendancy for the tail to swing, which usually produces some roll. Using the nose hook, which is well in front of the wheel, reduces the tendancy for a swinging tail. Another interesting thing I found about using the nose hook is that if the ship happens to vere towards, say the left, and the left wing starts to drop, the pull force of the tow rope will try to roll the ship, lifting the wing. I believe this is because of the larger moment arm (height) between the nose hook and the pavement. On the other hand, the CG hook is a very close to the pavement, so there is very little moment force to assist in rolling the ship back to level. Of course, this could be a disadvantage if the roll force caused by the tow is holding the wing down. But there are some cases when a wing drops that releasing is the best thing to do. BTW when using the CG hook (when there is little rolling force from the tow), I have found that the use of rudder to pick up a wing works very well if I rudder (turn) towards the wing that drops. When the ship is forced to turn in the direction of the dropping wing, the ship will roll to bring the wing back up. Its like riding a bicycle: if you happen to start falling to the left, you should steer to the left, otherwise you will fall over. I'm sure that there are a lot of pilots out there that don't believe this, but that's OK; this method works for me. Bob Salvo "Bill Daniels" wrote in message news:MBefd.247116$wV.107530@attbi_s54... "Bob Salvo" wrote in message ... Using the nose hook will reduce the tendancy for wing drops. Bob Salvo Really? Why? Bill Daniels |
#18
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I honestly can't tell any difference. I've made turning takeoffs so as to
be able to stage off the side of an active runway where the fuselage at the start of the roll was 30 degrees to the runway centerline. My Nimbus 2C with a CG hook just tracks where I want it to. I have no interest in adding a nose hook. I don't think it's a big deal. Like all tailwheel gliders I try to hold the tailwheel down hard until I get some rudder control then I lift the tail and just steer it where I want to go. I use the ailerons aggressively right from the start to hold the long wings level. The CG hook doesn't help, but it doesn't hurt either. There have been many millions of winch launches with CG hooks with no systemic problem with wing dropping. Bill Daniels "Bob Salvo" wrote in message ... Bill, Not sure, but when I sealed over my nose hook on the H301 and used the CG hook for aertow, I had more trouble keeping a wing from dropping. I think when the CG hook is used and there is a wind gust from the side at the start of launch, there is more tendancy for the tail to swing, which usually produces some roll. Using the nose hook, which is well in front of the wheel, reduces the tendancy for a swinging tail. Another interesting thing I found about using the nose hook is that if the ship happens to vere towards, say the left, and the left wing starts to drop, the pull force of the tow rope will try to roll the ship, lifting the wing. I believe this is because of the larger moment arm (height) between the nose hook and the pavement. On the other hand, the CG hook is a very close to the pavement, so there is very little moment force to assist in rolling the ship back to level. Of course, this could be a disadvantage if the roll force caused by the tow is holding the wing down. But there are some cases when a wing drops that releasing is the best thing to do. BTW when using the CG hook (when there is little rolling force from the tow), I have found that the use of rudder to pick up a wing works very well if I rudder (turn) towards the wing that drops. When the ship is forced to turn in the direction of the dropping wing, the ship will roll to bring the wing back up. Its like riding a bicycle: if you happen to start falling to the left, you should steer to the left, otherwise you will fall over. I'm sure that there are a lot of pilots out there that don't believe this, but that's OK; this method works for me. Bob Salvo "Bill Daniels" wrote in message news:MBefd.247116$wV.107530@attbi_s54... "Bob Salvo" wrote in message ... Using the nose hook will reduce the tendancy for wing drops. Bob Salvo Really? Why? Bill Daniels |
#19
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Bill Daniels wrote:
I honestly can't tell any difference. I've made turning takeoffs so as to be able to stage off the side of an active runway where the fuselage at the start of the roll was 30 degrees to the runway centerline. My Nimbus 2C with a CG hook just tracks where I want it to. I have no interest in adding a nose hook. I don't think it's a big deal. Like all tailwheel gliders I try to hold the tailwheel down hard until I get some rudder control then I lift the tail and just steer it where I want to go. I use the ailerons aggressively right from the start to hold the long wings level. The CG hook doesn't help, but it doesn't hurt either. There have been many millions of winch launches with CG hooks with no systemic problem with wing dropping. There wouldn't be any with the nose hook, either, since most of the wing dropping is due to towplane wake which isn't present with a winch, and a smaller number due to slow acceleration (I'm guessing more winches provide good acceleration than towplanes). My experience, and that of many others, is gliders with long wings or water ballast are less likely to drop a wing, simply because of inertia. Nose hooks are a proven advantage over CG hooks for aerotow, but not primarily for wing dropping reasons; of course, the size of the advantage varies with the glider and the pilot. -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
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