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#1
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I was thinking about the ATSM and JAR-22 for Special Light Sport
Aircraft. Since SLSA are really between Standard and Experimental certificates, applying JAR-22 in its entirety seems overregulating. I noticed FAA US AC 21.17-2A invokes the JAR-22 standard for gliders as 3.0kg/meter squared. This means a 1320lb standard glider would need a 14.2 meter wingspan. Although this does give "good" glide performance, the intent of the Light Sport Aircraft standards are NOT good performance. The intent is "light" and "sport." I suggest the ATSM standard for Special Light Sport Aircraft be less restrictive. I suggest 6.0kg/meter squared is a better figure. This allows what is still a reasonable glide (15:1 or so), and gives a clear distinction between airplanes and gliders. The Diamond Katana DA-C1, which is right at the cusp between glider and airplane, has a 7.0 kg/meter squared ratio. Yet its glide ratio is between 12 and 14. There are a bunch of benefits to this relaxed requirement. One is that the resulting aircraft could have a span as little as 11 meters. This means it can go into what have become "airplane sized" hangars. A 14 meter wingspan just doesn't fit in a T-hangar. Clever designers could also make 2 meter tip extensions to be added at the pilot discretion, to make it a 15 meter glider. Maybe a clever way to store the extensions inside the aircraft in a "hat rack" setup so one could motor to Minden, then fly in wave at a wicked snot fast speed. Then land, put the extensions on, fill up to ballast at 1320lbs, and go thermal. All this without having to get an airplane license. And then fly home and put it in the hangar. The 3.0kg/meter sq restriction is certainly a good cutoff for high performance gliders, but for LSA, 6.0kg/meter sq results in only a 29% reduction in span, which is critical to meet the realities of standard hangars, but still clearly is an industry consensus standard for a difference between gliders and airplanes. Otherwise JAR-22 seems pretty good as one of the acceptable standards for LSA. Anybody on the NTSM standards committee interested? -- ------------+ Mark J. Boyd |
#2
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Ooops, the title should have said 6.0 kg/meter sq...
Sorry ![]() -- ------------+ Mark J. Boyd |
#3
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Hmmmmm.....
Since ATSM is "Acute Traumatic Stress Management," perhaps that is off topic. The better known "American Society for Testing and Materials (ASTM)" is the more relevant and less dyslexic group that is developing SLSA standards,right? ![]() In article 41bb4fbc$1@darkstar, Mark James Boyd wrote: I was thinking about the ATSM and JAR-22 for Special Light Sport Aircraft. Since SLSA are really between Standard and Experimental certificates, applying JAR-22 in its entirety seems overregulating. I noticed FAA US AC 21.17-2A invokes the JAR-22 standard for gliders as 3.0kg/meter squared. This means a 1320lb standard glider would need a 14.2 meter wingspan. Although this does give "good" glide performance, the intent of the Light Sport Aircraft standards are NOT good performance. The intent is "light" and "sport." I suggest the ATSM standard for Special Light Sport Aircraft be less restrictive. I suggest 6.0kg/meter squared is a better figure. This allows what is still a reasonable glide (15:1 or so), and gives a clear distinction between airplanes and gliders. The Diamond Katana DA-C1, which is right at the cusp between glider and airplane, has a 7.0 kg/meter squared ratio. Yet its glide ratio is between 12 and 14. There are a bunch of benefits to this relaxed requirement. One is that the resulting aircraft could have a span as little as 11 meters. This means it can go into what have become "airplane sized" hangars. A 14 meter wingspan just doesn't fit in a T-hangar. Clever designers could also make 2 meter tip extensions to be added at the pilot discretion, to make it a 15 meter glider. Maybe a clever way to store the extensions inside the aircraft in a "hat rack" setup so one could motor to Minden, then fly in wave at a wicked snot fast speed. Then land, put the extensions on, fill up to ballast at 1320lbs, and go thermal. All this without having to get an airplane license. And then fly home and put it in the hangar. The 3.0kg/meter sq restriction is certainly a good cutoff for high performance gliders, but for LSA, 6.0kg/meter sq results in only a 29% reduction in span, which is critical to meet the realities of standard hangars, but still clearly is an industry consensus standard for a difference between gliders and airplanes. Otherwise JAR-22 seems pretty good as one of the acceptable standards for LSA. Anybody on the NTSM standards committee interested? -- ------------+ Mark J. Boyd -- ------------+ Mark J. Boyd |
#4
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![]() "Mark James Boyd" wrote in message news:41bb4fbc$1@darkstar... snip Clever designers could also make 2 meter tip extensions to be added at the pilot discretion, to make it a 15 meter glider. Maybe a clever way to store the extensions inside the aircraft in a "hat rack" setup so one could motor to Minden, then fly in wave at a wicked snot fast speed. Then land, put the extensions on, fill up to ballast at 1320lbs, and go thermal. Or motor at wicked snot speed to a glider contest, then put on the wing tips and begin towing. All this without having to get an airplane license. And then fly home and put it in the hangar. The 3.0kg/meter sq restriction is certainly a good cutoff for high performance gliders, but for LSA, 6.0kg/meter sq results in only a 29% reduction in span, which is critical to meet the realities of standard hangars, but still clearly is an industry consensus standard for a difference between gliders and airplanes. Otherwise JAR-22 seems pretty good as one of the acceptable standards for LSA. Anybody on the NTSM standards committee interested? -- ------------+ Mark J. Boyd |
#5
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Please give people more information in your posts.
Your posts should have more substance, you should spend some time to write your opinion on the subject, you should include relevant links etc. Andre Mark James Boyd wrote: Ooops, the title should have said 6.0 kg/meter sq... Sorry ![]() -- ------------+ Mark J. Boyd |
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