The GPS-196 includes a really neat glide-ratio automated calculation and display, if you select it. In fact, if you select a target, it will tell you whether your glide will reach it. or not. By coincidence, while taking some review lessons last night, I discovered this ability and created one screen that displays ONLY this information. It shows four big blocks on the screen. They are
* GLIDE RATIO * GLIDE RATIO TO TARGET (required to reach the target) * COURSE TO TARGET * HEADING TO STEER (to target) PROCEDUE TO CREATE THIS PAGE; * Go to the numerical data page. (one of only 4 main pages) * PRESS "MENU" * SELECT "SET UP PAGE LAYOUT" * "ENTER" * SELECT "4 BIG FIELDS" OPTION * "ENTER" * PRESS "MENU" * SELECT "CHANGE DATA FIELDS" * "ENTER" TWICE * SELECT ONE OF THE FOUR BLOCK TITLES ABOVE FOR EACH BLOCK IN TURN * "ENTER" FOR EACH BOX AFTER SELECTING * PRESS "QUIT" TWICE Now you have an emergency glide display screen. You can keep it as one of your four main pages OR you can preserve it as an option for call-up only when you need it. In an emergency, if you have a desirable landing point available on the GPS, just select it as your destination and then bring up your nifty "glide screen". It will tell you in short order if you can reach your target, and it automatically includes field altitude in that calculation. (I do realize, of course, that if you find yourself without power and only a couple of thousand feet up, other issues will probably be more urgent.) This screen is also handy just for finding out what is your best distance glide-speed. Note that it does not tell you how to stay in the air for the longest time. It only tells you how to glide the longest distance. I suppose this ability must also be available on the 296, 396, and 496, but I did not confirm it. Dave Winters -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ed Burkhead Sent: Wednesday, January 21, 2009 1:07 PM To: [email protected]; ety Subject: [ercoupe-tech] Coupe glide ratio Darick, Clever idea, doing the measurement like that. It could give a useable number. Was that all at idle power? A confounding factor is that turns use energy and the steepness and radius of the turns determines how much energy is lost in the turn. However, that 8.5:1 ratio sounds like the ballpark glide ratio for the Coupe. The only really careful and accurate glide ratio testing I've heard of in the last 30 years was mine and it was all bollixed up due to the airspeed indicator I didn't know was faulty. The numbers I got were in that range too (after making guestimate adjustments for the ASI error), perhaps, better at a bit higher airspeeds. Your estimate of 8.5:1 is consistent with my best guess for glide ratio for around 70-80 mph. If someone would like to do rigorous glide ratio testing, here is a pretty good procedure - the old fashioned way. It's kind of tedious, but that's what's needed for rigorous testing of something like glide ratio. http://edburkhead. <http://edburkhead.com/Ercoupe/performance_information.htm> com/Ercoupe/performance_information.htm click on glide ratio testing. Some new electronic instruments will give a continuous readout of glide ratio based on altitude, temperature, indicated airspeed and altitude. My Stratomaster Extreme instrument package claims that ability but it'll be in my Challenger if I ever get that finished. For that matter, my Garmin GPS will also give a glide ratio readout. I bet many other good GPS units will do that, too. Hope several of you do some testing at various airspeeds and report the details (including details of your plane and its special drag features [venturi, landing gear fairings, landing gear mounted landing lights, etc.]). Hummmmm, the idea of doing this testing with a glide ratio readout GPS really sounds tempting. Go, people, Go! Ed
