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#51
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Over the last 15 years or so our instrument panels
have become much more interesting, displaying vastly more information than previously. During the same period there has been a significant increase in the number of pilots with the skill (and willingness) to soar very close to other sailplanes. The accidents are caused by our willingness to fly in a close proximity to other gliders, that produces the level of risk that produces the accidents we have. A gadget that worked, if such were possible, would probably have us all flying closer and closer together until we got back up to the same (maximum acceptable) perceived level of risk. At 23:54 01 May 2004, Mark James Boyd wrote: In article , Mike, The FLARM concept has been painfully obvious, from a technology point of view, since the introduction of low-cost GPS. In fact, it could even have been partially implemented with LORAN, but those receivers were expensive and were never widely deployed. Unfortunately, FLARM-type collision avoidance is only going to work if it's deployed to virtually all aircraft, which would require the authorities to insist on it. This won't happen: ADS-B is the chosen approach. Sort of important to this approach is 'is it worth it?' and 'does the solution cause more death than the problem?' Kind of like parachutes. If the added weight increases the marginal stall speed to the point it causes .001% more fatal accidents, but only saves .0092% more pilots in breakups, then it was a bad idea. Of course it's extremely unlikely anyone can prove the extra 15 pounds was the cause of fatality, right? How many added fatalities will there be because the pilot is distracted by the bleepy noise, even though the aircraft would have missed by six inches if neither pilot was aware? How many will die because of the distraction itself? This is just too hard to calculate. Huge numbers (hours of flight)multiplied by tiny estimated numbers (risk of midair) makes for a tough comparison. Now instead of risk use cost in $$$$s to implement, and the true cost vs. benefit is very difficult to estimate correctly... -- ------------+ Mark Boyd Avenal, California, USA |
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Andy Durbin wrote:
trajectory of each aircraft, but also predict collisions based on all possible future trajectories for the next say 30 seconds. Try Say 15 seconds, rather. I think it's useless to predict what will happen in 30 seconds. Even if concentration is not at its maximum for a moment, 15 seconds should be more than sufficient to avoid a collision IF YOU SEE THE OTHER A/C. resolving that mess when there are 30+ gliders at the top of the same thermal waiting for a contest start. The false alarm rate would be unacceptable. I don't think so. I was at the ``kickoff-meeting'' of FLARM at the ETH Zuerich, and I can assure you that the developers are very well aware of this problem and have adressed it. There are algorithms which perform well in that kind of situation and given that the workload is divided among all 30+ FLARMs CPU performance is expected to be sufficient. The developers cited extensive simulations which they did with IGC traces and it seems that the ``false alarm'' rate was low. That said, of course I can at the moment only cite and trust the developers, and a system like FLARM needs to prove itself in practice. There are too many factors which influence collision probability that I'd dare a prediction here. But it's an interesting concept and if the technical/regulatory question marks can be cleared up, we'll soon have some data on whether it can help reducing accident rates or not. Kind regards, -Gerhard -- Gerhard Wesp o o Tel.: +41 (0) 43 5347636 Bachtobelstrasse 56 | http://www.cosy.sbg.ac.at/~gwesp/ CH-8045 Zuerich \_/ See homepage for email address! |
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Chris Rollings wrote:
Over the last 15 years or so our instrument panels have become much more interesting, displaying vastly more information than previously. During the same period there has been a significant increase in the number of pilots with the skill (and willingness) to soar very close to other sailplanes. The accidents are caused by our willingness to fly in a close proximity to other gliders, that produces the level of risk that produces the accidents we have. A gadget that worked, if such were possible, would probably have us all flying closer and closer together until we got back up to the same (maximum acceptable) perceived level of risk. What situations are you thinking of where this would be true? I don't think it would be true for thermalling together, especially in contests, as I believe we already fly as close as practical. Flying closer would make it too hard to maintain safe separation (because of turbulence, the need to maneuver some, and the inability to hold a perfect circle), even with a warning device. Possibly, we would even fly farther apart to reduce the number of alarms (this would likely depend on the precise behavior of the unit), or because we would realize we were not as safe as we thought. I believe this requires flight testing to determine. Perhaps it would be true for ridge soaring together, but again, maybe the alarms would actually cause us to maintain greater distance. -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
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At 11:30 02 May 2004, Gerhard Wesp wrote:
Say 15 seconds, rather. I think it's useless to predict what will happen in 30 seconds. something capable of predicting what a human being WILL do next whatever the time scale. Now that would be something. |
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"Eric Greenwell" wrote in message ... Don Johnstone wrote: It seems to me that several people think that the introduction of technology will be simple, it won't. The problem is extremely complex. Ony if you think the problem is 40 gliders instead of 3 or 4, which is all that was involved in the recent collisions. I'm not a programmer, but I work with them on a daily basis. It seems to me that even a 3 or 4 glider problem is highly complex because sailplanes fly in highly irregular paths. We don't even fly straight point to point--we weave left and right, we dolphin. A ship might be going (more or less) straight and a couple hundred feet below me. Not a threat, right? Maybe, maybe not--what if I'm in a thermal and he's seen me and plans to join me. He suddenly converts speed to altitude and he's in my blind spot. My GPS has a 4 second polling cycle. Ooops. What if two ships are in a thermal but maintaining separation. Everything's fine, right? Sure, until we get to the top of the lift band and he suddenly tightens his turn to go through the core as he heads out on course. Have you ever flown in a thermal with even 10 gliders? I have many times. I can not keep track of even 10 gliders, but I can still thermal safely when there are that many and more. We are not flying around at random, but circling in an orderly fashion. Only the nearby gliders are a threat that must be monitored. In any case, a system that deals with only a few gliders will cover most of the situations. Orderly? To you and I yes. To a program? Not really. Think about what happens at cloudbase in a contest gaggle. The (mostly) orderly and similar actions (mostly same speed & bank angle) get more random. Some pilots increase their radius purposefully suboptimizing climb rates, others deploy a bit of spoiler, others leave. How are these actions to be predicted? Even if I have a 1 second polling rate on my GPS & "traffic analysis/collision avoidance system", how many variables can change in that one second and how fast can my safe separation be erased? Still leaves the problem of how you keep the pilot informed, display in the cockpit? I don't think so. Having sorted out all that, what does a pilot do in response to an urgent warning of collision, turn into another glider which was not logged as a threat until the sudden evasive turn was made. Technology might give the warning but it is the human that has to react. These are not new questions, so you can be assured that people contemplating these systems are considering them. Systems do not spring fully featured and perfect from the mind of an engineer, but proceed through stages of development and testing. Exactly what problems and benefits will appear during this process can't be predicted very well. I personally don't think we have the technology or expertise to design such a system or indeed the expertise to put it in a small enough space to fit in a glider right now, and the cost could be more than the average glider is worth. I am not saying do nothing, what I am saying is do something realistic and achievable now. I have little doubt that what has been proposed will be with us in 10 years time but it is now that we have a problem. I stand by what I originally wrote, humans are the cause of accidents, humans can prevent accidents. Whether we have the will to do it is another matter entirely. What must we do? Propose something - we're listening. Here's my modest proposal, eat them. Sorry, trying again-- Don't ask the system to figure collision potential and don't introduce another screen. Just have a system call out "target NNW, same altitude, closing @ x". If I see it, I say something like "clear" or "check" and the system stops alerting me to the known target. If I don't acknowledge the target the system continues to provide information at regular intervals to help me find it. I might be re-notified of "cleared" targets if we continue to fly in proximity to one another. Frankly, I can't imagine a user interface that would be useful in a large gaggle. That's probably OK because that's where we're likely to be most alert to this type of threat. Brent |
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303pilot wrote:
"Eric Greenwell" wrote in message Ony if you think the problem is 40 gliders instead of 3 or 4, which is all that was involved in the recent collisions. I'm not a programmer, but I work with them on a daily basis. It seems to me that even a 3 or 4 glider problem is highly complex because sailplanes fly in highly irregular paths. But still more manageable the 40, right :} ? But to answer the question, and keeping in mind I don't know any details of the Flarm system, it may not be possible or necessary to have a TCAS-like system. Though several gliders flying at random may indeed be complex, the algorithms chosen can make simplifying assumptions based on the nature of glider flight. Also, the pilot arriving at a thermal might modify his arrival to keep the threat level low, compared to how he does it now, so as not to "alarm" the pilots already in the thermal (and for other situations, also, not just thermals). We don't even fly straight point to point--we weave left and right, we dolphin. A ship might be going (more or less) straight and a couple hundred feet below me. Not a threat, right? Maybe, maybe not--what if I'm in a thermal and he's seen me and plans to join me. He suddenly converts speed to altitude and he's in my blind spot. My GPS has a 4 second polling cycle. Ooops. Most GPS receivers we use emit at once a second, though _flight recorders_ might record at a slower rate (the newer ones will also record at once per second). Rate isn't a problem. What if two ships are in a thermal but maintaining separation. Everything's fine, right? Sure, until we get to the top of the lift band and he suddenly tightens his turn to go through the core as he heads out on course. This simple situation is likely easy to handle. It should cause some alarms in both cockpits, unless it is a diving exit, which would put him well below the still thermalling glider! I'm sure anyone contemplating these systems has thought of these situations and more, and intends to cope with them, and use extensive testing to validate the equipment. As I mentioned before, the equipment might cause changes in pilot behavior, perhaps because they wish to avoid causing alarms, or because they now realize better the dangers involved. Have you ever flown in a thermal with even 10 gliders? I have many times. I can not keep track of even 10 gliders, but I can still thermal safely when there are that many and more. We are not flying around at random, but circling in an orderly fashion. Only the nearby gliders are a threat that must be monitored. In any case, a system that deals with only a few gliders will cover most of the situations. Orderly? To you and I yes. To a program? Not really. Think about what happens at cloudbase in a contest gaggle. The (mostly) orderly and similar actions (mostly same speed & bank angle) get more random. Some pilots increase their radius purposefully suboptimizing climb rates, others deploy a bit of spoiler, others leave. How are these actions to be predicted? Even if I have a 1 second polling rate on my GPS & "traffic analysis/collision avoidance system", how many variables can change in that one second and how fast can my safe separation be erased? In one second? Very few. Gliders simply don't react quickly in roll, and pilots don't pitch rapidly in the cloudbase gaggle. The ones I've been in, everyone is changing direction smoothly and slowly. Away from a gaggle, pitch changes can occur rapidly, but one second still seems short enough to me. It would be better to seek the opinion of someone actually attempting this, of course! snip What must we do? Propose something - we're listening. Here's my modest proposal, eat them. Sorry, trying again-- Don't ask the system to figure collision potential and don't introduce another screen. Just have a system call out "target NNW, same altitude, closing @ x". If I see it, I say something like "clear" or "check" and the system stops alerting me to the known target. If I don't acknowledge the target the system continues to provide information at regular intervals to help me find it. If I were designing a system, I'd make this capability the first phase. Perhaps it would be good enough. I'd try a button on the stick before the confirmation. I might be re-notified of "cleared" targets if we continue to fly in proximity to one another. Frankly, I can't imagine a user interface that would be useful in a large gaggle. That's probably OK because that's where we're likely to be most alert to this type of threat. Brent -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
#57
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The FLARM device not only provides traffic advisories, it tracks ground
hazards like towers and wires. It's also a IGC logger. Most handheld computers do several million floating point operations per second (MIPS) Hundreds of MIPS are available on low power CPU's. That's enough to compute trajectories on 40+ gliders in the 1/2 second interval between GPS fixes. Having enough computer power is not a problem. There are a lot of smarter people than me who could do the programming but maybe I can help with a flowchart. Step one: Are there any targets within one kilometer? If yes, provide count. Step two: Are any of these targets within + or - 200 meters of my altitude? If yes, proceed to step three. If not, ignore. Step three: For any targets within + or - 200 meters of my altitude, is the slant range increasing or decreasing? If increasing, ignore. If decreasing go to step four. Step four: For targets within +- 200 meters and closing, is the relative bearing changing less than 10 degrees per second? If yes, sound alarm and provide relative bearing and range. If greater, do nothing. Step four is a bit of oversimplification, for example, the critical rate of change for relative bearing increases for closer targets, which would require a look-up table or formula. Still, this is not a complicated algorithm. Bill Daniels "Eric Greenwell" wrote in message ... 303pilot wrote: "Eric Greenwell" wrote in message Ony if you think the problem is 40 gliders instead of 3 or 4, which is all that was involved in the recent collisions. I'm not a programmer, but I work with them on a daily basis. It seems to me that even a 3 or 4 glider problem is highly complex because sailplanes fly in highly irregular paths. But still more manageable the 40, right :} ? But to answer the question, and keeping in mind I don't know any details of the Flarm system, it may not be possible or necessary to have a TCAS-like system. Though several gliders flying at random may indeed be complex, the algorithms chosen can make simplifying assumptions based on the nature of glider flight. Also, the pilot arriving at a thermal might modify his arrival to keep the threat level low, compared to how he does it now, so as not to "alarm" the pilots already in the thermal (and for other situations, also, not just thermals). We don't even fly straight point to point--we weave left and right, we dolphin. A ship might be going (more or less) straight and a couple hundred feet below me. Not a threat, right? Maybe, maybe not--what if I'm in a thermal and he's seen me and plans to join me. He suddenly converts speed to altitude and he's in my blind spot. My GPS has a 4 second polling cycle. Ooops. Most GPS receivers we use emit at once a second, though _flight recorders_ might record at a slower rate (the newer ones will also record at once per second). Rate isn't a problem. What if two ships are in a thermal but maintaining separation. Everything's fine, right? Sure, until we get to the top of the lift band and he suddenly tightens his turn to go through the core as he heads out on course. This simple situation is likely easy to handle. It should cause some alarms in both cockpits, unless it is a diving exit, which would put him well below the still thermalling glider! I'm sure anyone contemplating these systems has thought of these situations and more, and intends to cope with them, and use extensive testing to validate the equipment. As I mentioned before, the equipment might cause changes in pilot behavior, perhaps because they wish to avoid causing alarms, or because they now realize better the dangers involved. Have you ever flown in a thermal with even 10 gliders? I have many times. I can not keep track of even 10 gliders, but I can still thermal safely when there are that many and more. We are not flying around at random, but circling in an orderly fashion. Only the nearby gliders are a threat that must be monitored. In any case, a system that deals with only a few gliders will cover most of the situations. Orderly? To you and I yes. To a program? Not really. Think about what happens at cloudbase in a contest gaggle. The (mostly) orderly and similar actions (mostly same speed & bank angle) get more random. Some pilots increase their radius purposefully suboptimizing climb rates, others deploy a bit of spoiler, others leave. How are these actions to be predicted? Even if I have a 1 second polling rate on my GPS & "traffic analysis/collision avoidance system", how many variables can change in that one second and how fast can my safe separation be erased? In one second? Very few. Gliders simply don't react quickly in roll, and pilots don't pitch rapidly in the cloudbase gaggle. The ones I've been in, everyone is changing direction smoothly and slowly. Away from a gaggle, pitch changes can occur rapidly, but one second still seems short enough to me. It would be better to seek the opinion of someone actually attempting this, of course! snip What must we do? Propose something - we're listening. Here's my modest proposal, eat them. Sorry, trying again-- Don't ask the system to figure collision potential and don't introduce another screen. Just have a system call out "target NNW, same altitude, closing @ x". If I see it, I say something like "clear" or "check" and the system stops alerting me to the known target. If I don't acknowledge the target the system continues to provide information at regular intervals to help me find it. If I were designing a system, I'd make this capability the first phase. Perhaps it would be good enough. I'd try a button on the stick before the confirmation. I might be re-notified of "cleared" targets if we continue to fly in proximity to one another. Frankly, I can't imagine a user interface that would be useful in a large gaggle. That's probably OK because that's where we're likely to be most alert to this type of threat. Brent -- Change "netto" to "net" to email me directly Eric Greenwell Washington State USA |
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I can think of ways to filter for only the most proximate
threats, even in a gaggle (closest proximity, closing rate, etc). What seems to me would be difficult in a gaggle setting is figuring out what to do once everyone starts maneuvering in response to alerts - it could quickly get overwhelming. Even so, more information is likely better than less under most circumstances. 9B At 21:12 03 May 2004, Eric Greenwell wrote: 303pilot wrote: 'Eric Greenwell' wrote in message Ony if you think the problem is 40 gliders instead of 3 or 4, which is all that was involved in the recent collisions. I'm not a programmer, but I work with them on a daily basis. It seems to me that even a 3 or 4 glider problem is highly complex because sailplanes fly in highly irregular paths. But still more manageable the 40, right :} ? But to answer the question, and keeping in mind I don't know any details of the Flarm system, it may not be possible or necessary to have a TCAS-like system. Though several gliders flying at random may indeed be complex, the algorithms chosen can make simplifying assumptions based on the nature of glider flight. Also, the pilot arriving at a thermal might modify his arrival to keep the threat level low, compared to how he does it now, so as not to 'alarm' the pilots already in the thermal (and for other situations, also, not just thermals). We don't even fly straight point to point--we weave left and right, we dolphin. A ship might be going (more or less) straight and a couple hundred feet below me. Not a threat, right? Maybe, maybe not--what if I'm in a thermal and he's seen me and plans to join me. He suddenly converts speed to altitude and he's in my blind spot. My GPS has a 4 second polling cycle. Ooops. Most GPS receivers we use emit at once a second, though _flight recorders_ might record at a slower rate (the newer ones will also record at once per second). Rate isn't a problem. What if two ships are in a thermal but maintaining separation. Everything's fine, right? Sure, until we get to the top of the lift band and he suddenly tightens his turn to go through the core as he heads out on course. This simple situation is likely easy to handle. It should cause some alarms in both cockpits, unless it is a diving exit, which would put him well below the still thermalling glider! I'm sure anyone contemplating these systems has thought of these situations and more, and intends to cope with them, and use extensive testing to validate the equipment. As I mentioned before, the equipment might cause changes in pilot behavior, perhaps because they wish to avoid causing alarms, or because they now realize better the dangers involved. Have you ever flown in a thermal with even 10 gliders? I have many times. I can not keep track of even 10 gliders, but I can still thermal safely when there are that many and more. We are not flying around at random, but circling in an orderly fashion. Only the nearby gliders are a threat that must be monitored. In any case, a system that deals with only a few gliders will cover most of the situations. Orderly? To you and I yes. To a program? Not really. Think about what happens at cloudbase in a contest gaggle. The (mostly) orderly and similar actions (mostly same speed & bank angle) get more random. Some pilots increase their radius purposefully suboptimizing climb rates, others deploy a bit of spoiler, others leave. How are these actions to be predicted? Even if I have a 1 second polling rate on my GPS & 'traffic analysis/collision avoidance system', how many variables can change in that one second and how fast can my safe separation be erased? In one second? Very few. Gliders simply don't react quickly in roll, and pilots don't pitch rapidly in the cloudbase gaggle. The ones I've been in, everyone is changing direction smoothly and slowly. Away from a gaggle, pitch changes can occur rapidly, but one second still seems short enough to me. It would be better to seek the opinion of someone actually attempting this, of course! snip What must we do? Propose something - we're listening. Here's my modest proposal, eat them. Sorry, trying again-- Don't ask the system to figure collision potential and don't introduce another screen. Just have a system call out 'target NNW, same altitude, closing @ x'. If I see it, I say something like 'clear' or 'check' and the system stops alerting me to the known target. If I don't acknowledge the target the system continues to provide information at regular intervals to help me find it. If I were designing a system, I'd make this capability the first phase. Perhaps it would be good enough. I'd try a button on the stick before the confirmation. I might be re-notified of 'cleared' targets if we continue to fly in proximity to one another. Frankly, I can't imagine a user interface that would be useful in a large gaggle. That's probably OK because that's where we're likely to be most alert to this type of threat. Brent -- Change 'netto' to 'net' to email me directly Eric Greenwell Washington State USA |
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I don't think anyone would maneuver in response to the alert, they would
maneuver in response to what their eyes told them when they looked at the threat in response to the alert. Bill Daniels "Andy Blackburn" wrote in message ... I can think of ways to filter for only the most proximate threats, even in a gaggle (closest proximity, closing rate, etc). What seems to me would be difficult in a gaggle setting is figuring out what to do once everyone starts maneuvering in response to alerts - it could quickly get overwhelming. Even so, more information is likely better than less under most circumstances. 9B At 21:12 03 May 2004, Eric Greenwell wrote: 303pilot wrote: 'Eric Greenwell' wrote in message Ony if you think the problem is 40 gliders instead of 3 or 4, which is all that was involved in the recent collisions. I'm not a programmer, but I work with them on a daily basis. It seems to me that even a 3 or 4 glider problem is highly complex because sailplanes fly in highly irregular paths. But still more manageable the 40, right :} ? But to answer the question, and keeping in mind I don't know any details of the Flarm system, it may not be possible or necessary to have a TCAS-like system. Though several gliders flying at random may indeed be complex, the algorithms chosen can make simplifying assumptions based on the nature of glider flight. Also, the pilot arriving at a thermal might modify his arrival to keep the threat level low, compared to how he does it now, so as not to 'alarm' the pilots already in the thermal (and for other situations, also, not just thermals). We don't even fly straight point to point--we weave left and right, we dolphin. A ship might be going (more or less) straight and a couple hundred feet below me. Not a threat, right? Maybe, maybe not--what if I'm in a thermal and he's seen me and plans to join me. He suddenly converts speed to altitude and he's in my blind spot. My GPS has a 4 second polling cycle. Ooops. Most GPS receivers we use emit at once a second, though _flight recorders_ might record at a slower rate (the newer ones will also record at once per second). Rate isn't a problem. What if two ships are in a thermal but maintaining separation. Everything's fine, right? Sure, until we get to the top of the lift band and he suddenly tightens his turn to go through the core as he heads out on course. This simple situation is likely easy to handle. It should cause some alarms in both cockpits, unless it is a diving exit, which would put him well below the still thermalling glider! I'm sure anyone contemplating these systems has thought of these situations and more, and intends to cope with them, and use extensive testing to validate the equipment. As I mentioned before, the equipment might cause changes in pilot behavior, perhaps because they wish to avoid causing alarms, or because they now realize better the dangers involved. Have you ever flown in a thermal with even 10 gliders? I have many times. I can not keep track of even 10 gliders, but I can still thermal safely when there are that many and more. We are not flying around at random, but circling in an orderly fashion. Only the nearby gliders are a threat that must be monitored. In any case, a system that deals with only a few gliders will cover most of the situations. Orderly? To you and I yes. To a program? Not really. Think about what happens at cloudbase in a contest gaggle. The (mostly) orderly and similar actions (mostly same speed & bank angle) get more random. Some pilots increase their radius purposefully suboptimizing climb rates, others deploy a bit of spoiler, others leave. How are these actions to be predicted? Even if I have a 1 second polling rate on my GPS & 'traffic analysis/collision avoidance system', how many variables can change in that one second and how fast can my safe separation be erased? In one second? Very few. Gliders simply don't react quickly in roll, and pilots don't pitch rapidly in the cloudbase gaggle. The ones I've been in, everyone is changing direction smoothly and slowly. Away from a gaggle, pitch changes can occur rapidly, but one second still seems short enough to me. It would be better to seek the opinion of someone actually attempting this, of course! snip What must we do? Propose something - we're listening. Here's my modest proposal, eat them. Sorry, trying again-- Don't ask the system to figure collision potential and don't introduce another screen. Just have a system call out 'target NNW, same altitude, closing @ x'. If I see it, I say something like 'clear' or 'check' and the system stops alerting me to the known target. If I don't acknowledge the target the system continues to provide information at regular intervals to help me find it. If I were designing a system, I'd make this capability the first phase. Perhaps it would be good enough. I'd try a button on the stick before the confirmation. I might be re-notified of 'cleared' targets if we continue to fly in proximity to one another. Frankly, I can't imagine a user interface that would be useful in a large gaggle. That's probably OK because that's where we're likely to be most alert to this type of threat. Brent -- Change 'netto' to 'net' to email me directly Eric Greenwell Washington State USA |
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On Sun, 02 May 2004 00:19:47 GMT, "Bill Daniels"
wrote: Yes I do fly in the vast empty skies of the western USA, thank goodness. However, I'm also a pilot who has survived a mid-air with another glider while flying in those "empty" skies. Try to picture this. The little device goes "Beep" and when you look at it, the 20mm 2-digit LED display says "06" meaning 6 gliders are within one kilometer. My reaction is to look outside like crazy until I can see all six. It beeps again and displays 07 meaning that another glider has joined the gaggle. I look even harder. This uses the "Mark 1 eyeball" to it's maximum. Extremely accurate GPS data has nothing to do with this. If the error is that the 7th glider is really 1.005 Km away instead of 1.000 why would I care? If a glider joins the gaggle without this device there is a very good chance I will see him while looking for the others even though the device does not detect him. It is not necessary to compute the trajectories of all gliders in the gaggle to determine those with a collision probability. Those 500 feet above and below present no danger whatsoever. Now picture an advanced version. The device still displays "07" but it now sounds "deedle, deedle, deedle" and an LED at 8 O'clock illuminates meaning that there is a non-zero probability collision threat at that relative bearing. The "Mark 1 eyeballs" leap into action and I look over my left shoulder to see that the other glider will pass clear. Is this a "false alarm"? Not really. I really wanted to see him if he was that close. I appreciated the "heads up". The device need only compute probabilities for those targets near and closing while near the same altitude. Perhaps the problem is calling this an "Anti-Collision Device" when it is really a situational awareness aid. As for battery life, perhaps you noticed the news that a fully IFR equipped Kestral 17 flown by Gordon Boettger flew 1562 Kilometers in 11:15 from Minden, Nevada, USA to Steamboat Springs, Colorado. Most of the flight was in wave above 20,000 feet. Gordon's Kestral was transponder equipped as well as carrying a lot of other electronics to operate legally in positive control airspace. Battery capacity didn't seem to be a problem. The device I'm talking about would weigh less than 200 gms and run on four AA batteries for 50+ hours. The amount of time spent looking at it will be fractions of a second and then only when critical information is displayed. Bill Daniels "electronically enhanced see and avoid" is what we are really after here, not a 100% guaranteed collision prevention system. Nearly all gliders already have a GPS of some sort so part of the hardware already exists. For those who insist on greater than once per second updates go to the Garmin website and look at the new Garmin 16A engine which provides 5 Hz updates. This is however, unnecessary. As someone said here "the glider you don't see is the one that will get you".(not necessarily true) An electronic system will help with this which is why fighters got tail warning radar not long after the invention of radar itself. Advocating training or better behaviour by pilots probably won't work. If it did we'd know by now. The collisions we have are the ones left AFTER this has already been done. Could some people do better? - yes. This has been going on for 90 years now. Ask the victims of Manfred von Richthofen, Billy Bishop, Albert Ball and all the others. Even the aces got surprised occasionally and survived by luck(Adolph Galland) or not. You don't need any display in the cockpit, just a voice.(no panel space required) Some years ago we owned a Nimbus 3DM and it was remarkable how often a second pair of eyes would pick up something that one missed. The electronic systems like FLARM will provide that second pair of eyes in single seat gliders. It isn't necessary to have a 100% system. We already do that with parachutes and in the military, ejection seats. Neither are 100% effective. When the alternative is almost certain death even a 50% mitigator looks good. Any National gliding body responsible for regulation could trial such a system at any given site and then go on to require its use nationwide. Mike Borgelt |
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Anti collision light mod for Piper Arrow 1968 model? | Frode Berg | Owning | 4 | May 20th 04 05:16 AM |
New anti collision system for aircrafts, helicopters and gliders | Thierry | Owning | 10 | February 14th 04 08:36 AM |
USAF = US Amphetamine Fools | RT | Military Aviation | 104 | September 25th 03 03:17 PM |