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#11
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Wing Launch - Can it pull your wings off?
Derek C wrote:
The consequence of using a 10% weaker link would be a greater chance of a broken weak link and a failed launch, which might be hazardous in itself under some circumstances. No, never! A cable brake is routine and *never* hazardous in *any* circumstances. If it is, then something in your operation is seriously flawed. But a cable brake (or weak link brake) is always an annoyance, as it interrupts the operation. |
#12
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Wing Launch - Can it pull your wings off?
On Aug 14, 11:30*am, John Smith wrote:
Derek C wrote: The consequence of using a 10% weaker link would be a greater chance of a broken weak link and a failed launch, which might be hazardous in itself under some circumstances. No, never! A cable brake is routine and *never* hazardous in *any* circumstances. If it is, then something in your operation is seriously flawed. Depends on the size and nature of the airfield. Our site at Lasham in the UK is large and flat, and gives you a wide range of options after a winch launch failure. I have flown at a small sloping German site where they launched without a weak link because having a weak link failure was considered a serious hazard. Having said that the speed control and quality of their winch launches was very good. Derek C |
#13
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Wing Launch - Can it pull your wings off?
On Aug 14, 3:30*am, John Smith wrote:
No, never! A cable brake is routine and *never* hazardous in *any* circumstances... I do envy your faith in the ubiquity of human competence. Thanks, Bob K. |
#14
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Wing Launch - Can it pull your wings off?
Derek C wrote:
On Aug 14, 11:30 am, John wrote: No, never! A cable brake is routine and *never* hazardous in *any* circumstances. If it is, then something in your operation is seriously flawed. Depends on the size and nature of the airfield. Our site at Lasham in the UK is large and flat, and gives you a wide range of options after a winch launch failure. I have flown at a small sloping German site where they launched without a weak link because having a weak link failure was considered a serious hazard. Hmmmmm... I've experienced firsthand a fair number of rope brakes on the winch (but interestingly not a single weak link break), and hence consider a rope break pretty much SOP when winching. So I'm not sure I'd want to fly at that German site. I have no problem with an airfield where a cable brake puts me in a difficult situation which requires special procedures but a cable brake shall never be hazardous. |
#15
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Wing Launch - Can it pull your wings off?
On Aug 14, 9:36*am, Bob Kuykendall wrote:
On Aug 14, 3:30*am, John Smith wrote: No, never! A cable brake is routine and *never* hazardous in *any* circumstances... I do envy your faith in the ubiquity of human competence. Thanks, Bob K. Bob, John Smith is correct. If a cable break appears hazardous for a particular pilot, then that pilot is seriously under-trained. Almost 90% of winch training is directed to safely handling rope breaks and a good winch instructor just won't sign a pilot off until a safe outcome is assured. Note that I said "rope" since steel cable is no longer insurable in the US. Breaks should be totally routine and pilots should handle them instinctively. |
#16
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Wing Launch - Can it pull your wings off?
On Aug 13, 12:00*pm, bildan wrote:
If your glider was certified with an Approved Flight Manual, as all JAR-22 gliders are, FAR's require you to operate in compliance with that manual. Please be more specific. What particular FAR requires me to operate my experimental (racing and exhibition) ASW-28 in compliance with the flight manual? The Experimental Operating Limitations contain specific extracts from the flight manual that I am required to comply with. If content of the flight manual was not extracted and included in the Experimental Operating Limitations I am not aware that is has any regulatory significance. The flight manual extracts included in my limitations relate only to maximum gross weight, allowable CG range, and maximum operating speeds. Sure, I recognize that it would be good practice to read and comply with the flight manual, but that is not the same as being required to do so by federal regulation. Andy |
#17
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Wing Launch - Can it pull your wings off?
On Aug 14, 5:28*pm, Andy wrote:
On Aug 13, 12:00*pm, bildan wrote: If your glider was certified with an Approved Flight Manual, as all JAR-22 gliders are, FAR's require you to operate in compliance with that manual. Please be more specific. *What particular FAR requires me to operate my experimental (racing and exhibition) ASW-28 in compliance with the flight manual? The Experimental Operating Limitations contain specific extracts from the flight manual that I am required to comply with. *If content of the flight manual was not extracted and included in the Experimental Operating Limitations I am not aware that is has any regulatory significance. The flight manual extracts included in my limitations relate only to maximum gross weight, allowable CG range, and maximum operating speeds. Sure, I recognize that it would be good practice to read and comply with the flight manual, but that is not the same as being required to do so by federal regulation. Andy Every E&R Experimental operations limitations letter I've seen requires operation in compliance with the AFM. FAR Part 91.9(a) requires operation in compliance with an AFM if one is part of the original airworthiness certification. (i.e JAR-22) I'm very sure (based on FAA interpretations) if an E&R airworthiness certificate is issued for a glider which had a standard airworthiness certificate with AFM in it's country of origin, the mere issuance of a US E&R airworthiness certificate does not excuse the owner of the glider from compliance with the AFM. |
#18
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Wing Launch - Can it pull your wings off?
On 8/14/2010 8:17 AM, Derek C wrote:
On Aug 14, 11:30 am, John wrote: Derek C wrote: The consequence of using a 10% weaker link would be a greater chance of a broken weak link and a failed launch, which might be hazardous in itself under some circumstances. No, never! A cable break is routine and *never* hazardous in *any* circumstances. If it is, then something in your operation is seriously flawed. Depends on the size and nature of the airfield. Our site at Lasham in the UK is large and flat, and gives you a wide range of options after a winch launch failure. I have flown at a small sloping German site where they launched without a weak link because having a weak link failure was considered a serious hazard. Having said that the speed control and quality of their winch launches was very good. Derek C Out of genuine curiosity, can you share more details of "small sloping...site"? I have difficulty imagining a winch site unsuitable for either a straight ahead landing following an 'early-early' launch problem not also suitable for a 360-to-a-return-at-the-launch-point for a 'later-in-time' launch problem. I am assuming a 'reasonably powered winch' of course, which I imagine is the German norm. Short of an anemic winch with the winch/line stashed down a road in a copse of woods, my imagination fails me here. My experience in the western U.S. (generally 5000' msl) is any field considered 'distance-suitable' for (even marginal) aerotowing is - in a launch-emergency sense - far more 'emergency-option-friendly' than aerotowing, because you never get dragged at low altitude over completely unlandable terrain...which is definitely *not* the case in these parts with aerotowing. Are there folks winch launching from postage-stamp-sized-fields surrounded by unlandable terrain using a beyond-the-boundary-winch? Curiously, Bob W. |
#19
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Wing Launch - Can it pull your wings off?
On Aug 14, 3:43*pm, bildan wrote:
Bob, John Smith is correct. *If a cable break appears hazardous for a particular pilot, then that pilot is seriously under-trained. *Almost 90% of winch training is directed to safely handling rope breaks and a good winch instructor just won't sign a pilot off until a safe outcome is assured. *Note that I said "rope" since steel cable is no longer insurable in the US. Breaks should be totally routine and pilots should handle them instinctively. I'm sorry, Bill, I'm still not buying it. It's the word "never" that rings my bell. I don't much hold with either "always" or "never." All dangers are relative. The added hazards of a cable break may be fairly low, but I am confident that rigorous analysis will demonstrate them to be statistically significant. Even the most competent pilots have their off days and off minutes, and the intersection of those times and trying circumstances can and too often will be troublesome. Note that I do not argue that winch launching is to any great degree dangerous. That is not the case. I believe that, when executed conscientiously, winch launching can equal or better the safety record of aerotow. What I do argue is that every soaring operation entails non-trivial risk, and that those risks can only be greater when things do not go as planned or expected. Thanks, Bob K. |
#20
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Wing Launch - Can it pull your wings off?
On Aug 14, 5:24*pm, John Smith wrote:
Derek C wrote: On Aug 14, 11:30 am, John *wrote: No, never! A cable brake is routine and *never* hazardous in *any* circumstances. If it is, then something in your operation is seriously flawed. Depends on the size and nature of the airfield. Our site at Lasham in the UK is large and flat, and gives you a wide range of options after a winch launch failure. I have flown at a small sloping German site where they launched without a weak link because having a weak link failure was considered a serious hazard. Hmmmmm... I've experienced firsthand a fair number of rope brakes on the winch (but interestingly not a single weak link break), and hence consider a rope break pretty much SOP when winching. So I'm not sure I'd want to fly at that German site. I have no problem with an airfield where a cable brake puts me in a difficult situation which requires special procedures but a cable brake shall never be hazardous. The site in question is a narrow strip 800 metres long, sloping downhill at about 1 in 10, on top of a hill and totally surrounded by small unlandable vineyards. They always launched downhill, irrespective of wind direction. Once above about 200ft, but below circuit height, the only cable break option to get back onto site was a 180 degree turn (teardrop circuit) to land back uphill. The alternatives were a controlled crash into a vineyard or a water landing on the local river. I have also winch launched at a very small UK site called Sandhill Farm near Shrivenham in Wiltshire, which wasn't much better. At certain heights you only option was to land in one of the surrounding fields. They have since given up winch launching as they felt that the risk to reward (700-800ft launches) ratio was too great. The only problem with winch launching (of which I am a great fan) is that you need a reasonable large airfield to get decent heights and to do it safely without presenting pilots with extremely critical judgement decisions in the event of a launch failure. Derek C |
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