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#1
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Winch accident in New Zealand, can low time student pilot be blamed?
http://www.glidingmagazine.com/NewsArticle.asp?id=1371
http://www.glidingmagazine.com/ Correct "CG" release was used, which on PW5 is offsett forward of the CG. I was told that the nose hook is not allowed for winch towing of PW5. That's what manual sais, but who knows why? Which other gliders are not allowed to be winched by the nose? I was told that PW5 has front and rear ballast weights, how complicated is it? Who is resposible for checking weight and ballance, if for example student pilot has 3 hours (40 flights X 5min) of flight experience? When does resposibility of flight instructor end? Andre |
#2
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"Andre Volant" wrote in message om... http://www.glidingmagazine.com/NewsArticle.asp?id=1371 http://www.glidingmagazine.com/ Correct "CG" release was used, which on PW5 is offsett forward of the CG. As is supposed to be the case. I was told that the nose hook is not allowed for winch towing of PW5. That's what manual sais, but who knows why? Because winching with a nose hook causes a glider to porpoise. Which other gliders are not allowed to be winched by the nose? Any glider with a CG hook. Many gliders are equipped with ONLY a CG hook. I was told that PW5 has front and rear ballast weights, how complicated is it? Probably not complicated at all. Who is resposible for checking weight and ballance, if for example student pilot has 3 hours (40 flights X 5min) of flight experience? There was nothing in the Gliding Magazine story about this level of experience. However, 40 flights and 3:20 of instruction should have been plenty for a rated pilot to make the transition to winch launch. The pilot in command is always responsible for weight and balance. This post and the Gliding Magazine story seems to suggest that there is something wrong with the use of a CG hook. In fact, there is a great deal wrong with NOT using a CG hook for winch launch. A very FEW older gliders exhibit a behavior where the nose will pitch up uncontrollably if the winch acceleration is too strong. These gliders usually have high CG's, low CG hooks and small tail surfaces and/or all moving tails that limit down elevator authority. Good winch drivers know about them and reduce acceleration accordingly. I don't know if the PeeWee exhibits these characteristics - since it is a modern design, I doubt that it does. The usual cause for accidents of this type is a pilot who starts a climb before the glider achieves a safe airspeed. This can be compounded in modern gliders which often require NO back pressure to enter the climb. If the pilot in under the impression that a strong pull on the stick is required to enter the climb, problems of this sort may result. We need to wait the results of the investigation. Rushing to blame the glider design is almost always the wrong thing to do. Bill Daniels |
#3
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I had a Hornet kite on me one time the winch driver saw it and gave it to
the winch. The trim went to full back as I rotated as the aircraft has the stupidest spring loaded trim system in the world for winch launching DANGER ! Does the PW5 have the same trim system says the guy was Asian so most of them are light weights to add to his C of G problems. Mal "Bill Daniels" wrote in message news:dy6sd.186163$HA.103320@attbi_s01... "Andre Volant" wrote in message om... http://www.glidingmagazine.com/NewsArticle.asp?id=1371 http://www.glidingmagazine.com/ Correct "CG" release was used, which on PW5 is offsett forward of the CG. As is supposed to be the case. I was told that the nose hook is not allowed for winch towing of PW5. That's what manual sais, but who knows why? Because winching with a nose hook causes a glider to porpoise. Which other gliders are not allowed to be winched by the nose? Any glider with a CG hook. Many gliders are equipped with ONLY a CG hook. I was told that PW5 has front and rear ballast weights, how complicated is it? Probably not complicated at all. Who is resposible for checking weight and ballance, if for example student pilot has 3 hours (40 flights X 5min) of flight experience? There was nothing in the Gliding Magazine story about this level of experience. However, 40 flights and 3:20 of instruction should have been plenty for a rated pilot to make the transition to winch launch. The pilot in command is always responsible for weight and balance. This post and the Gliding Magazine story seems to suggest that there is something wrong with the use of a CG hook. In fact, there is a great deal wrong with NOT using a CG hook for winch launch. A very FEW older gliders exhibit a behavior where the nose will pitch up uncontrollably if the winch acceleration is too strong. These gliders usually have high CG's, low CG hooks and small tail surfaces and/or all moving tails that limit down elevator authority. Good winch drivers know about them and reduce acceleration accordingly. I don't know if the PeeWee exhibits these characteristics - since it is a modern design, I doubt that it does. The usual cause for accidents of this type is a pilot who starts a climb before the glider achieves a safe airspeed. This can be compounded in modern gliders which often require NO back pressure to enter the climb. If the pilot in under the impression that a strong pull on the stick is required to enter the climb, problems of this sort may result. We need to wait the results of the investigation. Rushing to blame the glider design is almost always the wrong thing to do. Bill Daniels |
#4
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I belong to the club where this happened .
The inquiry is still going on but from comments made by people actually there when it happened. The pilot had already flown earlier in the day in the same glider. The witnesses said the pilot rotated early and was a bit steep in the initial climb but then started to turn right when in full climb at around 300 ft, the deviation to the right continued until back release occurred when the PW5 promptly rolled into a spin. Partial recovery seemed to happen and the PW5 landed straddling a driveway. The farm type 7 wire fences on either side of that driveway acted like arrestor wires.The pilot has 2 broken ankles a broken arm and other minor injuries.The pilot I think is from Hong Kong and I believe has already been flown home. The PW5 is known to want to go to full climb quickly if not prevented but I know a Nimbus 2 will do exactly the same if winched a bit quick so don't blame the glider ,this accident has the look of pilot error. A lot of the training here is on the 2 seat PW6 so type conversion problems are likely not an issue. gary "Andre Volant" wrote in message om... http://www.glidingmagazine.com/NewsArticle.asp?id=1371 http://www.glidingmagazine.com/ Correct "CG" release was used, which on PW5 is offsett forward of the CG. I was told that the nose hook is not allowed for winch towing of PW5. That's what manual sais, but who knows why? Which other gliders are not allowed to be winched by the nose? I was told that PW5 has front and rear ballast weights, how complicated is it? Who is resposible for checking weight and ballance, if for example student pilot has 3 hours (40 flights X 5min) of flight experience? When does resposibility of flight instructor end? Andre |
#5
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goneill wrote:
The witnesses said the pilot rotated early and was a bit steep in the initial climb but then started to turn right when in full climb Judging from my lawn-chair, I'm tempted to say: Watch your airspeed! Stefan |
#6
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Andre,
Cg hooks require more pilot attention as the tow line/wire does not provide any additional stability as is the case with a nose hook. In fact, it can severly aggrevate misuse of the controls. This is why a nose hook is always preferred for aerotow. For ground launches using a nose hook, the principal problem would appear to be overpowering the elevator. The higher your angle of climb, the more elevator would be required to keep the cable from pitching the nose down. (A cg hook would not affect stick pressures since the force vector is through the glider's cg, ie, no/little forward pitch moment). Aside from load and structure problems, here's the real killer. If the cable breaks, you have nearly full rear stick applied. If not release immediataley, you are likely to enter a low altitude, accelerated stall. Bad news. I suspect that the problem related in the article was an acceleratated stall while still on the cable. This would explain loss of control and back release. It's not hard to see how an inexperienced pilot might abuse the controls during launch and wind up in just such a situation. (Andre Volant) wrote in message . com... http://www.glidingmagazine.com/NewsArticle.asp?id=1371 http://www.glidingmagazine.com/ Correct "CG" release was used, which on PW5 is offsett forward of the CG. I was told that the nose hook is not allowed for winch towing of PW5. That's what manual sais, but who knows why? Which other gliders are not allowed to be winched by the nose? I was told that PW5 has front and rear ballast weights, how complicated is it? Who is resposible for checking weight and ballance, if for example student pilot has 3 hours (40 flights X 5min) of flight experience? When does resposibility of flight instructor end? Andre |
#7
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On aerotow, my top two critical items on the PW-5 were
trim set forward spoilers locked I'd love to know where this PW-5 trim was set. Anyone look at it after the accident? I used to set 3 for launch, and use 7 or 8 (edge of stall) for thermalling only. In article , goneill wrote: I belong to the club where this happened . The inquiry is still going on but from comments made by people actually there when it happened. The pilot had already flown earlier in the day in the same glider. The witnesses said the pilot rotated early and was a bit steep in the initial climb but then started to turn right when in full climb at around 300 ft, the deviation to the right continued until back release occurred when the PW5 promptly rolled into a spin. Partial recovery seemed to happen and the PW5 landed straddling a driveway. The farm type 7 wire fences on either side of that driveway acted like arrestor wires.The pilot has 2 broken ankles a broken arm and other minor injuries.The pilot I think is from Hong Kong and I believe has already been flown home. The PW5 is known to want to go to full climb quickly if not prevented but I know a Nimbus 2 will do exactly the same if winched a bit quick so don't blame the glider ,this accident has the look of pilot error. A lot of the training here is on the 2 seat PW6 so type conversion problems are likely not an issue. gary "Andre Volant" wrote in message . com... http://www.glidingmagazine.com/NewsArticle.asp?id=1371 http://www.glidingmagazine.com/ Correct "CG" release was used, which on PW5 is offsett forward of the CG. I was told that the nose hook is not allowed for winch towing of PW5. That's what manual sais, but who knows why? Which other gliders are not allowed to be winched by the nose? I was told that PW5 has front and rear ballast weights, how complicated is it? Who is resposible for checking weight and ballance, if for example student pilot has 3 hours (40 flights X 5min) of flight experience? When does resposibility of flight instructor end? Andre -- ------------+ Mark J. Boyd |
#8
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---------- Dans l'article , Stefan a écrit : goneill wrote: The witnesses said the pilot rotated early and was a bit steep in the initial climb but then started to turn right when in full climb Judging from my lawn-chair, I'm tempted to say: Watch your airspeed! Not only the airspeed. As the load factor may be high despite the pilot doesn't feel it, the angle of attack may be near the stall angle with a speed well over the normal 1g stall speed. Maybe the only symptom of the near stall angle of attack in this case is the loss of roll damping and the ensuing tendancy to drop a wing which is much more easily countered with the rudder than the elevator. The fact that the glider involved in the accident started to bank to the right may be an indication that this was the case. |
#9
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Chris OCallaghan wrote: I suspect that the problem related in the article was an acceleratated stall while still on the cable. This would explain loss of control and back release. It's not hard to see how an inexperienced pilot might abuse the controls during launch and wind up in just such a situation. Agree -- In Nova Scotia, at a winch only club with 20+ years experience, a fatal accident occurred during a launch. The pilot accelerated and took off normally, then rotated toward full climb sooner than we teach. The HP18 had a high speed stall and spun rapidly on the wire and into the ground from no more than 300 feet. This was the pilot's second launch of the day. The first was normal. Too steep too soon can result in a high speed stall. I winch launched my PW5 at this home club for five years -- no problems but I paid close attention to maintaining control of the flight attitude and launch profile -- as I did on all the other ships that the club operates. The club Ka8 was noticeably harder to control at the begining of a launch but we never had a launch accident with either glider type. |
#10
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On Fri, 03 Dec 2004 23:21:46 GMT, Bill Daniels wrote:
"Andre Volant" wrote in message om... http://www.glidingmagazine.com/NewsArticle.asp?id=1371 http://www.glidingmagazine.com/ Correct "CG" release was used, which on PW5 is offsett forward of the CG. As is supposed to be the case. I was told that the nose hook is not allowed for winch towing of PW5. That's what manual sais, but who knows why? Because winching with a nose hook causes a glider to porpoise. Which other gliders are not allowed to be winched by the nose? Any glider with a CG hook. Many gliders are equipped with ONLY a CG hook. I was told that PW5 has front and rear ballast weights, how complicated is it? Probably not complicated at all. Who is resposible for checking weight and ballance, if for example student pilot has 3 hours (40 flights X 5min) of flight experience? There was nothing in the Gliding Magazine story about this level of experience. However, 40 flights and 3:20 of instruction should have been plenty for a rated pilot to make the transition to winch launch. The pilot in command is always responsible for weight and balance. This post and the Gliding Magazine story seems to suggest that there is something wrong with the use of a CG hook. In fact, there is a great deal wrong with NOT using a CG hook for winch launch. A very FEW older gliders exhibit a behavior where the nose will pitch up uncontrollably if the winch acceleration is too strong. These gliders usually have high CG's, low CG hooks and small tail surfaces and/or all moving tails that limit down elevator authority. Good winch drivers know about them and reduce acceleration accordingly. I don't know if the PeeWee exhibits these characteristics - since it is a modern design, I doubt that it does. There have been a couple of incidents in OZ with PW-5s responding badly to aggressive winch acceleration. I don't know the details though. Cheers, John G. |
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