----- Original Message ----- From: "c d gundy" <[email protected]> To: "Ed Burkhead" <[email protected]> Sent: Wednesday, January 21, 2009 1:38:58 PM GMT -05:00 US/Canada Eastern Subject: Re: [ercoupe-tech] coupe landing
Guys, I intend to test for the min. airspeed as soon as my engine is back together and get the correct number for my ASI. I have been using 80mph as a landing speed and I have room left on the yoke to pull back and make a nice soft landing. Yesterday, wondering what the glide ratio was, I went into google earth, used the "ruler" which measures feet on the ground from a line you have drawn and measured the distance I travel from abeam the numbers in the pattern, which is where I drop to idle, downwind, base and final. I could do this looking down on my home airport as there are definite landmarks where the pattern is located. I understand this is really approximate and just a ball park fiqure, but nontheless, an interesting exercise. I calculated 8.5 to 1. Darick ----- Original Message ----- From: "Ed Burkhead" <[email protected]> To: "ety" <[email protected]> Sent: Saturday, January 17, 2009 10:40:06 PM GMT -05:00 US/Canada Eastern Subject: RE: [ercoupe-tech] coupe landing Airslot4518 wrote: > Down final I never fly less than 80 indicated. And Bart wrote: > Just establish a STABILIZED SPEED on final, usually about 65-70 > mph, then bring the power to idle and flare, Too many Coupes have inaccurate airspeed indicators to give people advice based on a numerical airspeed number. When I first bought my Coupe, I used the best published numbers for airspeeds in the pattern. On the second flight, the gas line iced up and I glided to my landing in a plowed field. THEN PUBLISHED NUMBERS WERE WRONG FOR MY PLANE because the airspeed indicator was old and worn and gave numbers 10-15 mph higher than my true "indicated airspeed" should have been. When I got to the flare and pulled back there was no "back" to pull to - I was already AT minimum flying speed at 70 mph indicated. With a new, calibrated ASI, that plane had a 55 mph minimum flying speed and 70 mph on final did give me a decent glide and lots of energy to flare. Even 65 mph was an OK approach speed in calm conditions. All the numbers I gave in my landing "essay" were in relation to a "minimum flying speed" determined by getting THAT airplane up high, pulling the power to idle and finding out how slow it goes according to THAT airplane's airspeed indicator. Then multiply that number times 1.3 or 1.4 or 1.5 to get the cushion numbers you want. This is an approximation, but it's way better than just saying an airspeed number. Both of you, Airslot and Bart are citing _right_ numbers for your plane and approach and see how different they are! Airslot's commented that the Coupe has a high sink rate and, judging from context, I think he meant a high sink rate at 80 mph indicated on final. At a true 80 indicated a Coupe should have a fairly decent glide ratio - not to compare it to a long-wing Cessna but decent. When was your ASI last calibrated, Airslot? We should all calibrate our airspeed indicators from time to time. Mine was sure way off. http://www.csgnetwork.com/tasgpscalc.html True airspeed calculator I'll go with Bart's "stabilized speed." I'll agree that, for Airslot, 80 on final is right for his plane. But, when giving general advice, we've got to be careful about numbers. Ed
