Glide should be better with the prop stopped rather than windmilling, Virg
On Sat, 11 Mar 2006 05:44:26 -0800 (PST) [email protected] writes: > Mark, > If you are doing landings from abreast the numbers with a big > slip, > you might make it with a dead engine. Did my landings the same way > in > the Mustang. When the engine quit for real, it amazed me how fast > it > came down with a prop stopped. Bobby > > > > > > > > Larry Flesner wrote: > > > >> I went for a short flight after work today and was going to check > my > >> speed > >> brake for you... > > > > I did that test for real today, since it was a calm day and I had > lots of > > time. Reality is closer to a 50% faster descent rate with flaps > than > > without, if you can believe what I did today. I'm not sure I do, > but it > > wouldn't surprise me either. Most of what I did today was good > > old-fashioned stopwatch and altimeter work, verified later by the > EIS > > altitude/time/speed/RPM record (the 26 data points per second > information > > that was used to create the plot at > > http://home.hiwaay.net/~langford/flights/flight98.gif ). > > > > I got my new replacement Sensenich 54x54 prop yesterday, so I also > did > > some > > more extensive speed and climb testing with the Sterba so I can > compare > > them > > after I put the Sensenich back on. I'm pretty confident with the > 162 mph > > true airspeed at 7500', which is what you'd call "cruise", I > guess. This > > is > > based on several 4-way GPS runs. Not bad considering I have no > spinner, > > wheelpants, or lots of other things that will further reduce drag > later. > > > > One thing I did test pretty carefully was glide ratio. Bottom > line from > > 8000' to 6000' is that I got 16.0:1 at 97 mph, which makes me feel > pretty > > good, considering how draggy my plane is at this point. That's an > average > > of 533'/min, so that tells me that I can climb out of the airport > and > > probably make it back if the engine croaks on climbout, since my > climb > > rate > > is an average of 750'/min from 800' to 5800' with full fuel at 90 > mph IAS > > (which is very close to TAS at low altitudes). > > > > Why am I doing all this testing knowing that it'll all be "wrong" > after I > > add wheelpants, etc.? Because I want to know how much difference > each > > improvement makes to the KR, so I'll know what I'm talking about > when I > > answer these questions > > > > I also worked on making my landings "power off" (idle, anyway) > from abeam > > the numbers to touchdown. This way if the engine quits I'll make > it > > anyway. > > I had to do several "maxed out" slips to get it down on the > numbers, but > > that was fun too. > > > > Since it's going to be warm but gusty tomorrow, maybe I'll start > doing a > > little body work, and clean up some of this drag...and also add a > blast > > tube > > to my Ellison's pressure regulator cover. > > > >> 198 hours at shutdown this evening with Langford gaining fast > !!!!! > > > > I did 2.3 hours today, so I'm now up to 158... > > > > Mark Langford, Harvest, AL > > see homebuilt airplane at http://www.N56ML.com > > email to N56ML "at" hiwaay.net > > > > > > > > > > _______________________________________ > > Search the KRnet Archives at > http://www.maddyhome.com/krsrch/index.jsp > > to UNsubscribe from KRnet, send a message to > [email protected] > > please see other KRnet info at http://www.krnet.org/info.html > > > > > _______________________________________ > Search the KRnet Archives at > http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to [email protected] > please see other KRnet info at http://www.krnet.org/info.html > > Virgil N. Salisbury - AMSOIL www.lubedealer.com/salisbury Miami ,Fl
