FW: RE: [RCSE] how high really
Using a Timex alti watch in my Windsong it recorded 3700' AGL as the highest attained. Mark Soaring Is Life!! RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
RE: [RCSE] how high really--Sorta
On a somewhat related note, I know some individuals have used a series of variying width white stripes on the lower surface of the wing as a means of estimating altitude. Obviously this method does not work for very high altitudes when the aircraft is at the very limits of one's vision. For us mere mortals however, it might prove useful. Does anyone have a reference, guide or link to information how one might go about utilizing these stripes as an aid? Specifically I am looking for suggested widths and placement of the stripes. Thanks very much. Dan RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really--Sorta
. Does anyone have a reference, guide or link to information how one might go about utilizing these stripes as an aid? Specifically I am looking for suggested widths and placement of the stripes. On another related note, most hunting scopes (for rifles) have graduated lines on the cross hairs to determine distance, the line spacing is typically the length of an average deer (about 6' but you need the specs for the scope). If you buy a cheap $20 to $40 9 to 20 power scope with a 40mm objective lens, you should be able to get a good estimate of distance based on the wing span against the reference lines, you should be able to see the plane much better too. Many marine binoculars also have similar reference lines. Mark Mech www.aerofoam.com RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really--Sorta
The July 1998 issue of RC Soaring Digest described a pattern of chordwise stripes of varying widths (6 to 1/2) which can be used to estimate altitude. We'll make the article available as a downloadable PDF on the RCSD web site, hopefully tomorrow, Thursday. RCSE subscribers and rcsoaringdigest Yahoo! group members will be notified as soon as it's available. Thanks for the suggestion! On Wed, 30 Aug 2006 22:26:22 -0500 Dan Ashenfelter [EMAIL PROTECTED] wrote: On a somewhat related note, I know some individuals have used a series of variying width white stripes on the lower surface of the wing as a means of estimating altitude. Obviously this method does not work for very high altitudes when the aircraft is at the very limits of one's vision. For us mere mortals however, it might prove useful. Does anyone have a reference, guide or link to information how one might go about utilizing these stripes as an aid? Specifically I am looking for suggested widths and placement of the stripes. Thanks very much. Dan Bill Bunny Kuhlman http://www.rcsoaringdigest.com RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
RE: [RCSE] how high really
Take a look at the Zlog. http://www.hexpertsystems.com/zlog/index.html It is an altitude data logger for $70. Bill Groft -Original Message- From: Lighthorse [mailto:[EMAIL PROTECTED] Sent: Sunday, August 27, 2006 10:44 AM To: CapnCrunchie; Soaring @ airage.com Subject: Re: [RCSE] how high really This would probably be cool to use Suunto e203 http://www.suuntowatches.com/Suunto-Escape.pro -- Ken York County Soaring Lighthorse Team YCS Silence is Golden On 8/27/06, CapnCrunchie [EMAIL PROTECTED] wrote: A good source for the Suunto altimeter watch is http://www.rei.com/outlet . Keep your eye out at this site because they often go on sale at the end of the seasons (summer/winter). I picked up mine for about $120 'n change... ;^) Blue skies, Doug Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail. RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.405 / Virus Database: 268.11.6/428 - Release Date: 8/25/2006 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.405 / Virus Database: 268.11.6/428 - Release Date: 8/25/2006 RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
RE: [RCSE] how high really
When I got my specs redone, I got into this discussion with my eye doc (that happened to be an ex-flight surgeon / perception researcher at Wright Patt) about flying RC sailplanes, and how I don't see that great at distance. He brought up an example about experiments with the red flag exercises in which fighter pilots did spot, identify, and shoot combat. In their experiments, the pilots were evenly matched, and the numbers suggested that the results should have been pretty even. They weren't. What they've added to the equation now is how well your eyes work together to spot and track a moving object. All these guys were great at identifying a static object at a distance, but when you put them in motion, some guys were much better than others. Just thought that was interesting, lift! B. From: Robert Samuels [EMAIL PROTECTED] if anyone out there can give us some research based information on far a human can discern an object like a 3m sailplane I'd sure like to hear it. RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really - lost planes
Regis wrote: A few months ago I lost site of a 3M plane in blue sky. There were about five of us watching when it just `blinked out`. Of course I tried to spin down but it never reappeared. A few weeks latter, another flier recounted a similar experience on this list. That got me thinking and I have arrived at a possible explanation. I think we flew through a boundary layer. The temperature is different on each side - as well as humidity etc. That bends the light. We all were looking where (in the direction) we last saw it - not where it actually was. A mirage is the result of such phenomena. Regis One visual phenomena most are not familiar with: without a clear object to focus on the eye relaxes. The distance this relaxed focus brings into sharp vision is relatively close and nowhere near the range we are searching when we lost sight of the plane. A clear sky makes life VERY difficult as there is nothing definitive to focus on, hence the eye relaxes and you lose the focus/ability to see small, distant objects. One thing that can help is to glance briefly at the horizon and then quickly look back to the search area. Frequent glances at a distinct, distant object will help maintain the eye focus at a distance, perhaps enabling you to reacquire sight of the lost plane. It is possible, with practice, to keep the eye muscles focused on a distant area without having a distinct object to focus on, but it is not easy and seems to require constant practice to maintain this ability. Hope this helps. Jim Porter Johnston Iowa USA The airplane stays up because it doesn't have the time to fall. Orville Wright RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
RE: [RCSE] how high really
A good source for the Suunto altimeter watch is http://www.rei.com/outlet. Keep your eye out at this site because they often go on sale at the end of the seasons (summer/winter). I picked up mine for about $120'n change... ;^)Blue skies, Doug Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail.
Re: [RCSE] how high really
This would probably be cool to use Suunto e203 http://www.suuntowatches.com/Suunto-Escape.pro -- Ken York County Soaring Lighthorse Team YCS Silence is Golden On 8/27/06, CapnCrunchie [EMAIL PROTECTED] wrote: A good source for the Suunto altimeter watch is http://www.rei.com/outlet . Keep your eye out at this site because they often go on sale at the end of the seasons (summer/winter). I picked up mine for about $120 'n change... ;^) Blue skies, Doug Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail. RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
If money is no object and you want to keep track of your max altitudes without the need of a laptop, one can go to Paragear and get some very ruggedequipment. Check eBay also for the same things. These units are tough and take a LOT of abuse - mine is constantly getting dropped and knocked around while gearing up..Blue skies, Capn Crunchie All-new Yahoo! Mail - Fire up a more powerful email and get things done faster.
Re: [RCSE] how high really
This is straying a little from the topic, however when flying my Sagitta 900 yesterday, I managed to fly it to a how really high altitude. It got higher after I engaged the spoilers and, to make a long story short, I lost it. I eyeballed where it went in, but is really hard to get to from where I stood in the land of trees and ridges(western Pa). I managed to borrow a friend's Garmin GPSII and have a question. Can I stand where I was when it went in and shoot a line to it and then pick up that line after getting across the ridge where it went in? - Original Message - From: Daryl Perkins [EMAIL PROTECTED] To: [EMAIL PROTECTED]; Randall Brust [EMAIL PROTECTED]; soaring@airage.com Sent: Saturday, August 26, 2006 6:36 PM Subject: Re: [RCSE] how high really When I talk about being at 8500 ft... the stabs had long since disappeared, the wings were literally toothpicks, and were disappearing as well - the fuse RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
RE: [RCSE] how high really
I got dropped off at 2,000 feet with a scale ship, all white, on a dark blue sky day... I had trouble seeing it immediately. Took about 2 minutes to (and it hurts to type this) bleed off altitude to get it where I was seeing it again. I've since gotten 'scrip sunglasses in a reddish brown to help with contrast, but it's the first time I felt like I was over 40 flying... Just glad I had spotters to keep me from getting in trouble, hope that I'm better next time out. Bill's right, it's too stressful to not see a ship, especially something that big. Who's bright idea was it to make scale ships white, any way? Makes me wish I'd installed strobes on the underside (or found clouds to get under quicker)... Hats of to you all that can see as far as I'm reading here, it's sure not me. B. RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
RE: [RCSE] how high really
Hey Daryl, I agree with you on the enjoyment level of CC as the pilot. Nobody can keep track of a XC plane at altitude, while bouncing down a dirt road at 80+mph, like Joe. It's amazing. My fun from XC came from spec-ing the plane out before handing the tranny over to Joe to start the course and in playing navigator/tactician/spotter while on course. Plus he's a fun guy to fly with. But if you guys really want to know the secret to Joe's success as a XC pilot, it's his wife Jan leadfoot Wurts. We had to fly fast just to keep up with the truck! Norm (humble member of Joe's Acme Sailplane Racing Team) -Original Message- From: Daryl Perkins [mailto:[EMAIL PROTECTED] Sent: Saturday, August 26, 2006 10:29 PM To: Soaring@airage.com Subject: Re: [RCSE] how high really You guys don't have to believe me... I had a tough time believing it myself. But one of the arts of cross country flying is keeping the model in the correct location in relation to the vehicle - virtually directly overhead. The reason for this is to maintain visual. I've seen the guys in Muncie flying CC at close to 4,000 ft off the tug tows(according to the pics), and they weren't even close to what Joe used to do. I was serious about not enjoying CC due to the constant extreme eyesight checks. Let's assume as much as a 10% error in the telemetry watch - That's still over 7500 ft. Our little td models are fairly easily visible from a front perspective up to a mile... why do you have such a tough time buying 8500 ft straight overhead? And that's with about a 13 inch chord and flat black bottoms... Give me a pic sometime and an Insanity (nowhere near the size of a CC model - about 20% smaller), and I'll prove it. hugs, D __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
RE: [RCSE] how high really
Brent: I did the same thing at Nats with Paul's SB-XC. After his Level-V out-and-return, I launched and thermaled it up, thinking that we'd go back out on course. I hooked up and got into the wide-spread upper-level lift under some darkening cues that were prevalent. I went through 700 meters like a shot and at 750 I started getting that it's not my airplane and I'm having trouble seeing it feeling. Then I thought, gee, I could be into the bases of the clouds at any time, so as it went up through 800 meters, I deployed full flaps and down trim. It was still going up, so I started to fly away from the cloud base trying to get *out* of lift. I topped out at 850 meters, which is just shy of 2,800 ft. I could still see the airplane OK, but I'm guessing that my personal visibility limit is about 3,500 ft with the SB. My scale Gerasis ASW-27 and its white-bottom wings has a practical limit of about 3,000, based on the Muncie aerotow events and Johnny Berlin's monster tows. And then I always try to have it under cloud, or down sun. Blue sky and up-sun is a recipe for a vanishing act. As it turned out, we didn't have the battery to go for a lap-plus run, so I brought it down and landed. Lesson learned! XC is a blast! Even though we on the DARTS team crew didn't touch the sticks due to Paul's Level-V attempt, we are every bit as involved in calling air and helping to decide when to drive, i.e., when and how to shoot the 3/10ths blind spot through the trees. We recruited Jim Thomas for Paul's successful Level-V run and his XC experience was invaluable. Daryl is right about the fly-high advice -- we tend to limp along from low save to low save. The year that Skip Miller went 64 miles at Nats, he was skied every time we saw him. One word to the wise, if you ever do XC with Ed Franz and he brings jerky along, check it for claws before digging in! I came REAL close to noshing on road-kill on year! Also, beware of the guys from Torrey Pines Gulls, they pack heat! (squirt guns; Ron, Arthur Don P-) -- Rudy Siegel, AMA 131126 CD Civis Aerius Sum Subject: RE: [RCSE] how high really Message-ID: [EMAIL PROTECTED] I got dropped off at 2,000 feet with a scale ship, all white, on a dark blue sky day... I had trouble seeing it immediately. Took about 2 minutes to (and it hurts to type this) bleed off altitude to get it where I was seeing it again. I've since gotten 'scrip sunglasses in a reddish brown to help with contrast, but it's the first time I felt like I was over 40 flying... Just glad I had spotters to keep me from getting in trouble, hope that I'm better next time out. Bill's right, it's too stressful to not see a ship, especially something that big. Who's bright idea was it to make scale ships white, any way? Makes me wish I'd installed strobes on the underside (or found clouds to get under quicker)... Hats of to you all that can see as far as I'm reading here, it's sure not me. B. RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
The highest that I've verified was around 1850 m if I remember correctly, a couple of years ago with a Picolario. I used to put my Casio altimeter watch in my XC, and it had a max altitude, along with max rate of climb and summation of altitude gained.The highest I recorded with the watch was about 5500 ft AGL, and a typical summation of climbs was in the vicinity of 30,000 feet for a full day of flying. A more interesting point was that I had almost 2 miles of slant range once... The funny thing was on the highest flight with the watch, I knew that I had been considerably higher previously, but hadn't a way to quantify the height. One thing about XC. Back when I used to do a bit more of it, I would try to get out to the flying site a day early so that I could practice. The primary goal of the practice was to get comfortable with flying at extreme altitudes. When you get comfortable, you want to be finding your next thermal at about the height that the stabs disappear. It starts getting hard to fly when the fuselage disappears, and all you are flying is a miniscule little hair line way up there. It is easy to get into heading PIO's at this height due to the lack of orientation feedback. I remember at least once where I accidently had turned the airplane 180 degrees without realizing it (symptoms of TOO HIGH). Some day I'll have time to get back to XC and play some more. It is one of the most pure forms of soaring. No launching wars, no stupid spearing of landing spots, just pure flying and soaring. Joe PS New email is joewurts at sbcglobal dot net. I don't check this one very much anymore (massive spam influx). RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
In a message dated 8/25/2006 8:55:17 P.M. Eastern Standard Time, [EMAIL PROTECTED] writes: But if anyone out there can give us some research based information on far a human can discern an object like a 3m sailplane I'd sure like to hear it. That would be good! Also, it would be pertinent to know what testing folks have performed to verify that true ambient static pressure is indeed being sensed (by these wonderful miniature recording barographs we have available today) under actual dynamic, in-flight, conditions. Depending on fuselage shape, alignment to the airstream, and in/out "leakage" paths, etc,pressure at the sensor could be higher (altitude reads low) or lower (altitude reads high)than ambient. Good Lift!
Re: [RCSE] how high really
When using these altitude watches be sure to read the included instructions very closely. Many of the ~$100 watches take pressure readings periodically only once every 2 mins. (or greater)and are made primarily for hikers/skiers. Suuto makes watches that can be set by user to take readings in intervals up to every 10 secs. but at the cost of battery endurance.However, by the time you get to this level of watch performance the price is approaching that of a piccalario!But then again, I am not going be to taking my vario with me as I am launching off intoBlack Diamond mogul filled torture test in sub freezing temperatures, either! ;^O)I don't know how pressure-sensitive/mounting position criticalthese model altitude recorders are - but I do know that the altimeters used in skydiving are notthat sensitiveto location (wrist/helmet/chest) where dramatic pressure changes are constantlyoccuringduring the jump due to body position. Only when I roll over on to my back do Isee adifference occurwith a chest mount altimeter. I don't believe vario mounting position inside a sailplane isgoing to make any appreciable difference in the accuracy of the reading.Blue skies, Capn Crunchie Get your own web address for just $1.99/1st yr. We'll help. Yahoo! Small Business.
Re: Re: [RCSE] how high really
Hello all:A couple of year ago we went through this debate and I (was taken to task) learned a lot about the new $200 alitimeters. However, we are rarely fly overhead, but at some angle, which means we are much farther away than upHowever, a soarer came on, who had done his math (geometery) and he simple stated thatat the height/distance of someones claim, adiameter of 1/32 piano wire held at arms length would completely cover the image of a 2m ship (at that height - not distance!) So if the ship is 4 meters, a piece of 1/16 wireThe geometry doesnt lie!!! And this was assuming that you were looking at the ship perpendicular to the top or bottom, (or coming right at you, ye, sure!!!) not at the angle we usually see the ship. This distance was about 1/2 of the height claimed. My son held the two meter junioraltitude record, ca 1800ft during the 70s. He had at least 15/20 vision -none of us witnessing the claim could really see the ship well enough to take accurate readings, so he flew overheadtill we could see it and take readings with transits. I am sure at 2500ft directly overhead, not at an angle, (most people think 75-80 degrees is overhead) he would have had a very hard time.The biggest problem with the cheapies is that they are not temperature compensated, or VERY poorly so.Those of us who were involved with altitude records during the 70s and 80s learned very quickly that how high you think you are and how high a Winter Baragraph tells you are very different. Jack Hiners record of 5000 was skill, luck, good weather(no haze), and trememdous eyesightAND it took him many, many , many attempts. His ship was alsoBIG!!! enough to house a full scale Winter Baragraph!!! What could he have done with a 10 gram - quarter size baragraphGood luck and have funJim
Re: [RCSE] how high really
JAMES EALY wrote: The biggest problem with the cheapies is that they are not temperature compensated, or VERY poorly so. There are 2 types of temperature dependance with respect to electronic altimeters. The first is how temperature change affects the pressure sensor's ability to convert pressure into voltage. This relationship should be absolutely constant no matter what temperature the sensor is at, but in the real world this is not the case. The current state of the art solid state sensors, however, do have built in temperature compensation circuitry and do a pretty good job in removing this effect. A large portion of the remaining temperature effect is also cancelled out since the AGL altitude is computed by measuring absolute altitude in the air, measuring absolute altitude at ground level, and subtracting the two values. The second is how temperature affects the pressure to altitude algorithm that all pressure based altimeters use to calculate altitude. Altimeters measure pressure, not altitude, so a model of the atmosphere is used which predicts how pressure varies with altiude. This is an ideal model so it obviously cannot match the real atmosphere at any time and any place on earth. The models are also based on an ideal sea level air temperature of 59F. So, if you're not flying at 59F, the model will be off. There are algorithms to compensate for this temperature effect and that's why our FlightView software allows you to enter the temperature of the day you were flying. It should be noted that this error can be quite large (like 5%-10%) if you are flying on a very hot or very cold day. It should also be noted that on hot days, the altimeter will actually read low, so if you fly your non-temperature compensated altimeter on a summer day and it says you were at 2000ft, you were probably higher. I'd also like to relate the following observation. When we were developing the RAM altimeters, we were flying them in 1.5m discus launch gliders and taking them pretty high. The plots showed that we were getting to around 2000ft. We initially didn't believe this so we measured out 2000ft at the flying field and one of us held up a glider while the other observed it from 2000ft away. It was definitely flyable at that distance and looked about right compared to what we saw in the air. It is also very important to understand how important the conditions are when flying at altitude. Contrary to what many believe, the worst type of conditions is a clear dark blue sky. The best is a clear sky with nice dense cumulus clouds. If you get a cloud behind your glider, you can see it twice as high as you can with blue sky behind it. Just don't fly out from in front of the cloud or Poof! it will be gone. :-) Randy Soaring Circuits RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
I have been following this thread with some interest and would to contribute my two undervalued cents. First, SIZE does count. Second, a number of years ago, Don Patterson and I were flying our Jerry Mirlk's designed AstroJeff's on a perfect day for high altitude flying. High clouds and some high haze to help visibility. The Jeff's sported an 11.00 root cord and a 12.00' wingspan. Both Jeff's were high enough that all we could see was a cross shape formed by the fuse and wing. The stabs had disappeared. Later after Don and I regained our senses and both got our AstroJeff's down on the ground one of our club members (his name escapes me) drove in to the Gdshs club field in Troy, MI. and told Don and I that he had circled our AstroJeffs at slightly above 5000' with his 1:1 Piper Cherokee. That would put our Jeffs at or above 4400' from us, since our club field was 600' above sea level. That sorta supports Jack Hiner's comments that the stabs on an AstroJeff disappear around 5000'. Three, Size still counts I say. Regards, Dave, I wish I was in Muncie this weekend, Corven. -- Original message -- From: Randall Brust [EMAIL PROTECTED] JAMES EALY wrote:is The biggest problem with the cheapies is that they are not temperature compensated, or VERY poorly so. There are 2 types of temperature dependance with respect to electronic altimeters. The first is how temperature change affects the pressure sensor's ability to convert pressure into voltage. This relationship should be absolutely constant no matter what temperature the sensor is at, but in the real world this is not the case. The current state of the art solid state sensors, however, do have built in temperature compensation circuitry and do a pretty good job in removing this effect. A large portion of the remaining temperature effect is also cancelled out since the AGL altitude is computed by measuring absolute altitude in the air, measuring absolute altitude at ground level, and subtracting the two values. The second is how temperature affects the pressure to altitude algorithm that all pressure based altimeters use to calculate altitude. Altimeters measure pressure, not altitude, so a model of the atmosphere is used which predicts how pressure varies with altiude. This is an ideal model so it obviously cannot match the real atmosphere at any time and any place on earth. The models are also based on an ideal sea level air temperature of 59F. So, if you're not flying at 59F, the model will be off. There are algorithms to compensate for this temperature effect and that's why our FlightView software allows you to enter the temperature of the day you were flying. It should be noted that this error can be quite large (like 5%-10%) if you are flying on a very hot or very cold day. It should also be noted that on hot days, the altimeter will actually read low, so if you fly your non-temperature compensated altimeter on a summer day and it says you were at 2000ft, you were probably higher. I'd also like to relate the following observation. When we were developing the RAM altimeters, we were flying them in 1.5m discus launch gliders and taking them pretty high. The plots showed that we were getting to around 2000ft. We initially didn't believe this so we measured out 2000ft at the flying field and one of us held up a glider while the other observed it from 2000ft away. It was definitely flyable at that distance and looked about right compared to what we saw in the air. It is also very important to understand how important the conditions are when flying at altitude. Contrary to what many believe, the worst type of conditions is a clear dark blue sky. The best is a clear sky with nice dense cumulus clouds. If you get a cloud behind your glider, you can see it twice as high as you can with blue sky behind it. Just don't fly out from in front of the cloud or Poof! it will be gone. :-) Randy Soaring Circuits RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
When I talk about being at 8500 ft... the stabs had long since disappeared, the wings were literally toothpicks, and were disappearing as well - the fuse was non-existent. That's how Joe consistently beat the pants off all the CC guys for all those years. The plane was always in the optimum position - right behind the tailgate of the truck, and he would only stop to thermal in a hat sucker, and he never let the model get much lower. Like I say... to be successful at cross country - If you are EVER comfortable seeing the plane, you're NOT high enough... At Taft, many years ago, I had to put in a time for Joe on Friday (I'd never flown cross country - Joe was out of town, and just needed a time and could make up whatever I lost the following 2 days). I was at the far turn in record time, I had the thermals for the ride home marked, and we were haulin' ass. That was right when I lost Wiley... Wiley did come home the following day unscathed(somebody found it about 7 miles off course), but I'll never hear the end of it... I've never really enjoyed cross country becasue of that experience. __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
Daryl says 8500'. Several guys have said 4500-5000'. OK, fine. Might as well be 100K to me. Well guys we're getting older and I'm seeing the decline in eye sight myself. How about you folks? Personally, I can't stand flying when I'm uncomfortable. Too stressful. Bill Swingle Janesville, CA Like I say... to be successful at cross country - If you are EVER comfortable seeing the plane, you're NOT high enough... RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: Re: [RCSE] how high really
Hi Bill:At 8000 ft a 4 meter planes image could fit in the area of a 1/64 diameter circle (at arms length). I am not sure a hawk could see that. But hey,thats just geometry and optics!!!best to you and our poor eyesight!regards,JimOn Sat, 26 Aug 2006 17:30:46 -0700 Bill Swingle wrote:Daryl says 8500. Several guys have said 4500-5000. OK, fine. Might as well be 100K to me. Well guys were getting older and Im seeing the decline in eye sight myself. How about you folks? Personally, I cant stand flying when Im uncomfortable. Too stressful. Bill Swingle Janesville, CA Like I say... to be successful at cross country - If you are EVER comfortable seeing the plane, youre NOT high enough... RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to https://webmail2.psu.edu/webmail/main.cgi#. Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format Jim EalyEducation by Demonstration
RE: [RCSE] how high really
The documentation for every FAI altitude record must include a calibration/compensation report for the recording barograph used for the attempt. Prior to our record attempts, I studied all available hardware and decided on a Suunto altimiter watch based on its specifications. I contacted AMA and got approval to use it. I took the watch to a certified FAA instrumentation lab for testing. After the results were tallied, I asked the tech who had run the tests what he thought about the watch. He smiled and gestured at another instrument on the bench. That, he said, is an altimeter out of a Lear Jet. It costs in the neighborhood of forty thousand dollars. It's not as accurate as your watch - and it displays much more hysteresis. Sadly, I had to actually buy my watch (ebay). Suunto gave Bob and me each a hat and t-shirt for setting the record. The Suunto watch does have some nice features like the ability to download flight (ski run) history and graph, export to excelIt is a LOT smaller than the old paper-spool pen barographs! MM From: CapnCrunchie [mailto:[EMAIL PROTECTED] Sent: Sat 8/26/2006 4:41 AM To: soaring@airage.com Subject: Re: [RCSE] how high really When using these altitude watches be sure to read the included instructions very closely. Many of the ~$100 watches take pressure readings periodically only once every 2 mins. (or greater) and are made primarily for hikers/skiers. Suuto makes watches that can be set by user to take readings in intervals up to every 10 secs. but at the cost of battery endurance. However, by the time you get to this level of watch performance the price is approaching that of a piccalario! But then again, I am not going be to taking my vario with me as I am launching off into Black Diamond mogul filled torture test in sub freezing temperatures, either! ;^O) . Blue skies, Capn Crunchie Get your own web address for just $1.99/1st yr http://us.rd.yahoo.com/evt=43290/*http://smallbusiness.yahoo.com/domains . We'll help. Yahoo! Small Business http://us.rd.yahoo.com/evt=41244/*http://smallbusiness.yahoo.com/ . RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
My Dad was one of very few human beings that was born in Taft back when, in 1927 or thereabouts. I have heard a lot of tales about living in a tent, big cats trying to eat his little sister, Grandpa drilling the first hole deeper than a mile, and of course the legendary Kern Mesa Thermals. Dad says that he flew a lot of free flight very early in the morning. After the sun had been up an hour he packed everything up and went home. Why? When he first started he tried trimming out a few free flight planes after 8 AM. He lost 5 models one morning. He said that you could give a free flight a hand toss to check trim and watch the model disappear virtually every time. If your tool box wasn't nailed down it was probably going to be lost as well. Absolutely perfect conditions for XC, but devastating for a kid with a bunch of free flight planes and limited budget. XC is an acquired taste, like a triple fermented bottle conditioned ale. It takes a lot of effort and some heartache and failure to really appreciate it when it works right. Conditions must be right, equipment must be right, and the participants must be ready and have their heads in the right space to take advantage of the event. But when all of this happens it's magic without any equal. As far as how high can you get? You can get a LOT higher than anybody would believe. It's a Zen Thing that no instrumentation will ever capture. If you can see the stabs then you're not ready to get on course yet. If you think that you need to see the airplane to fly it then think less. happy trails - Rob G Date: Sat, 26 Aug 2006 15:36:05 -0700 (PDT) From: Daryl Perkins [EMAIL PROTECTED] To: [EMAIL PROTECTED], Randall Brust [EMAIL PROTECTED], soaring@airage.com Subject: Re: [RCSE] how high really Message-ID: [EMAIL PROTECTED] When I talk about being at 8500 ft... the stabs had long since disappeared, the wings were literally toothpicks, and were disappearing as well - the fuse was non-existent. That's how Joe consistently beat the pants off all the CC guys for all those years. The plane was always in the optimum position - right behind the tailgate of the truck, and he would only stop to thermal in a hat sucker, and he never let the model get much lower. Like I say... to be successful at cross country - If you are EVER comfortable seeing the plane, you're NOT high enough... At Taft, many years ago, I had to put in a time for Joe on Friday (I'd never flown cross country - Joe was out of town, and just needed a time and could make up whatever I lost the following 2 days). I was at the far turn in record time, I had the thermals for the ride home marked, and we were haulin' ass. That was right when I lost Wiley... Wiley did come home the following day unscathed(somebody found it about 7 miles off course), but I'll never hear the end of it... I've never really enjoyed cross country becasue of that experience. RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
I asked permission from the CD during our last contest for orbital re-entry...;-) At 10:47 PM 8/26/2006, [EMAIL PROTECTED] wrote: As far as how high can you get? You can get a LOT higher than anybody would believe. It's a Zen Thing that no instrumentation will ever capture. If you can see the stabs then you're not ready to get on course yet. If you think that you need to see the airplane to fly it then think less. Jim Downers Grove, IL Member of the Chicago SOAR club, and Team JR AMA 592537LSF 7560 Level IV R/C Soaring blog at www.jimbacus.net RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
You guys don't have to believe me... I had a tough time believing it myself. But one of the arts of cross country flying is keeping the model in the correct location in relation to the vehicle - virtually directly overhead. The reason for this is to maintain visual. I've seen the guys in Muncie flying CC at close to 4,000 ft off the tug tows(according to the pics), and they weren't even close to what Joe used to do. I was serious about not enjoying CC due to the constant extreme eyesight checks. Let's assume as much as a 10% error in the telemetry watch - That's still over 7500 ft. Our little td models are fairly easily visible from a front perspective up to a mile... why do you have such a tough time buying 8500 ft straight overhead? And that's with about a 13 inch chord and flat black bottoms... Give me a pic sometime and an Insanity (nowhere near the size of a CC model - about 20% smaller), and I'll prove it. hugs, D __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
Re: [RCSE] how high really
This will be tough to do as Superman has long passed awayDan Robert Samuels [EMAIL PROTECTED] wrote: I'm now a believer. I believe that people believe what they are telling us. But these distances certainly far exceed my weak vision.I'm not an expert at anything much less how far one can see an object. But if anyone out there can give us some research based information on far a human can discern an object like a 3m sailplane I'd sure like to hear it.Robert Samuels ... St. Louis_Get the new Windows Live Messenger! http://imagine-msn.com/messenger/launch80/default.aspx?locale=en-ussource=wlmailtaglineRCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format Talk is cheap. Use Yahoo! Messenger to make PC-to-Phone calls. Great rates starting at 1/min.
Re: [RCSE] how high really
From: Robert Samuels [EMAIL PROTECTED] if anyone out there can give us some research based information on far a human can discern an object like a 3m sailplane I'd sure like to hear it. == Well, it depends on lighting and contrast. For resolving front-lit objects like lines on a page, various sources say that the human eye can resolve a pair of parallel lines that subtend 1 or 2 arc minutes (let's say 2 to be conservative). That means that if you had two parallel lines 10 feet apart, the best human vision could tell that there were two lines and not a single line if the pair were 17000 feet away! When you look at stars against a black sky, you can resolve smaller arcs. Some exceptionally gifted people can resolve Jupiter and one of its moons, or the North Star and its twin (there are actually 2 stars there, 18 arc-seconds apart. There's a third too, but only Hubble can see it). But seeing a wing against the sky depends not on the span, but on the chord. If the chord is 1 foot, it will subtend 2 arc-seconds at 1700 feet. The contrast is better than that of front-lit lines on a page, of course, so the eye can keep going. At 3400 feet, the 1-foot chord wing subtends 1 arc-second. Only really good eyes can see that, and it will be dependent on the brightness and character of the background. As you go on from there, you're surely getting to the limit of most people's vision. Both Babe Ruth (on his best day) and Albert Pujols have been reported to have 20/7 vision, almost 3x as acute as that of the poor middle-aged glider flyer. Perhaps if you want an altitude record, you could catch Albert on his day off to help spot the plane. RCSE-List facilities provided by Model Airplane News. Send subscribe and unsubscribe requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
