I did forget, on base it is our procedure to "clear" the engine by throttling up and down once. This slight rpm increase for 1 or 2 seconds is the extent of any extra energy on the landing sequence. I don't even look at the tach...it may only increase the rpm to 1000 or 1200. But, that may minimize the lose due to the turns.
I have read your procedure and was intending to use it as part of my spring "training". It's been 6 months since I've flown! Darick ----- Original Message ----- From: "Ed Burkhead" <[email protected]> To: "c d gundy" <[email protected]>, "ety" <[email protected]> Sent: Wednesday, January 21, 2009 2:06:46 PM GMT -05:00 US/Canada Eastern Subject: 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.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
