FlyingMonkey Posted July 1, 2014 Report Posted July 1, 2014 Hey all... The POH for my CTSW lists best glide speed as 62 knots at 15° flaps. It seems to glide fine in that configuration, if a bit steeply. I have read some say that 78 knots at 0° works better. It *seems* that more flaps would increase drag enough that it would give less glide performance, but I have not done any testing to confirm that. Of course less flaps also gives less lift, but if you can go faster then that might not matter if you are trying to get longest glide distance. Since -6° is our lowest drag setting, the actual ideal might be something like 78-82 knots at that setting. Does anybody know for sure?
Ed Cesnalis Posted July 1, 2014 Report Posted July 1, 2014 One thing we know for sure is that more flaps means a shorter glide. All you have to do is set up a glide to your field and once you have the field made deploy the flaps. Now you won't make it.
FlyingMonkey Posted July 1, 2014 Author Report Posted July 1, 2014 So you would vote for a -6 glide then, at some unspecified speed? Is the POH just wrong or dumbed-down to give a slower speed glide approach?
Ed Cesnalis Posted July 1, 2014 Report Posted July 1, 2014 So you would vote for a -6 glide then, at some unspecified speed? Is the POH just wrong or dumbed-down to give a slower speed glide approach? Since I verified that Josh was right on the flap setting I have not determined best speed to use. Your numbers above 78kts @ 0° seems fast.
FlyingMonkey Posted July 1, 2014 Author Report Posted July 1, 2014 Since I verified that Josh was right on the flap setting I have not determined best speed to use. Your numbers above 78kts @ 0° seems fast. I agree, I just remember seeing that in another post somewhere (and also thinking it was fast at the time).
FlyingMonkey Posted July 2, 2014 Author Report Posted July 2, 2014 The LS lists 71kts with 0°. That seems like a more plausible number for a CTSW as well. I will try to do some testing this weekend.
FlyingMonkey Posted July 2, 2014 Author Report Posted July 2, 2014 Nobody has done any testing on this in a CTSW, or has any more insight? Best glide seems a pretty important aspect of our airplanes' performance, I can't believe nobody has explored this in detail...
CT4ME Posted July 2, 2014 Report Posted July 2, 2014 It was beaten to death a long while back, but may have been on the other CT forum. There were a couple of crashes on that old forum and a lot of very good information was lost. Numerous people reported their results of in-air tests. It's certainly worth posting again. **edit** searching the forum for "glide ratio", I see quite a bit of discussion. Check it out.
Tony & Rose Posted July 2, 2014 Report Posted July 2, 2014 We're comfortable with 68kts with zero flap on our CTsw. We've 'toyed' with 'engine-out' configurations and feel this is 'best legs for stretching' the distance as mentioned. We use this configuration all the way to the touchdown (will slip as needed to shorten approach and speed), preferring to have a constant feel of the AC and not wanting to get involved in mid-course configuration control corrections to 'hit the target'.
FlyingMonkey Posted July 2, 2014 Author Report Posted July 2, 2014 Thanks, Tony & Rose. That sounds like a pretty good number, actually, close to the CTLS factory number of 71kt at 0° flaps. As I said, I hope to get some testing in this weekend and will post results.
Anticept Posted July 2, 2014 Report Posted July 2, 2014 Best glide is usually really close to best rate of climb. The prop effects do influence best rate a little bit. As for flap settings: I *believe* the setting designations are arbitrary, so ignore what the setting actually says. Generally you want flaps to be out of the airstream as much as possible in a power off best glide. I am not sure which will go further, or what the speeds need to be.
FlyingMonkey Posted July 2, 2014 Author Report Posted July 2, 2014 Best glide is usually really close to best rate of climb. The prop effects do influence best rate a little bit. As for flap settings: I *believe* the setting designations are arbitrary, so ignore what the setting actually says. Generally you want flaps to be out of the airstream as much as possible in a power off best glide. I am not sure which will go further, or what the speeds need to be. Maybe that is the basis of the 78kt number I mentioned I read somewhere. POH lists best climb as 78 knots (can't remember if 0 or -6).
Ed Cesnalis Posted July 2, 2014 Report Posted July 2, 2014 As I said, I hope to get some testing in this weekend and will post results. http://spirit.eaa.org/bitsandpieces/articles/2012-12_test-flight-card-best-glide-speed.asp
FlyingMonkey Posted July 3, 2014 Author Report Posted July 3, 2014 Looks like this will have to wait until my prop gets repaired.
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