---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Fri 05/22/15: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:39 AM - Re: Best glide speed RV6A (Doug Gray) 2. 08:19 AM - Re: Best glide speed RV6A (Dave Gmail) ________________________________ Message 1 _____________________________________ Time: 07:39:09 AM PST US Subject: Re: RV-List: Best glide speed RV6A From: Doug Gray Skylor, Yes that is as I recall, I think the best glide angle speed corresponds to t he tangent intercept drawn from the origin on the ROD plot. I will need to c heck my books to confirm. I need to figure out the best way to test these. Also I don't think I could h ave flown my aircraft anywhere near smoothly enough during phase 1 to have c ollected useful data. Thanks, Doug Sent from my iPhone > On 22 May 2015, at 1:31 pm, Skylor Piper wrote: > > "Best glide" usually refers to best glide angle, i.e. the speed at which t he aircraft will cover the most distance for a given amount of altitude loss in still air. In engine out situations, this is usually what we're interes ted in because we want to go the most distance possible with the amount of a ltitude that we have. I believe best glide angle typically coincides with t he speed at which L/D is the greatest in still air. > > Best endurance is the speed at which the rate of descent is minimum. This is useful for getting the most time possible for troubleshooting, but not n ecessarily traveling the greatest distance. Best endurance can occur at a s ignificantly lower airspeed than best angle, so while the rate of descent ma y be minimized, less forward progress is made per unit time resulting in a s teeper glide angle. > > Skylor > > Sent from my iPhone. > >> On May 21, 2015, at 6:54 PM, Doug Gray wrote: >> >> When discussing best glide I am never sure if we are talking about best g lide endurance or best glide range. Which do we use? >> I have never tested these on my RV-6 but intend to do so now the engine h as a couple of hundred hours. If someone can point me to a recommended proce dure this would be helpful too. >> Doug Gray >> >> Sent from my iPad >> >>> On 21 May 2015, at 9:18 am, Denis Walsh wrote: >>> >>> Charlie, I have a 6A, and I agree with your ball park figure; however I would caution there are many variables: prop (cs or fixed), power status (s topped prop or windmill), airplane weight, Idle rpm of your engine, etc. Th ere are probably more. >>> >>> In my case I have an average weight 180hp with c/s prop and low idle spe ed. I use 80 to 90 knots for glide and across the fence 75K. That leaves a lot of speed to kill in the flare but I have a low idle speed and lots of d rag if windmilling. This is what I practice with. It gives a rather steep g lide and I am sure it would be quite different with a stopped prop or parti al power, but I feel these would make for a better glide which I could deal w ith. I always practice with the prop in max RPM so I have max drag. >>> >>> One can practice for the zero thrust, min drag glide if you fiddle with the throttle to establish zero thrust, but I consider this to be too tough f or me and of minimal value in an emergency which will almost certainly be di fferent than you practiced any way! My opinion is the same about practicing with coarse pitch glides. I don=99t think you can count on having en ough oil pressure to go coarse pitch in many engine failure scenarios. So I just practice the worst case, with low pitch low rpm, and glide at 80-90, u ntil the field is made then flare, add drag and land. I figure if my emerge ncy has better glide angle than I have practiced, I can put the flaps down s ooner or side slip. Coming up short on final is, on the other hand usually n ot a good option. >>> >>> I certainly don=99t claim this is the best or the only way to prac tice, it=99 s just the way I do it, as you asked, based on a lot of pr actice over the past 18 years and 3100 hours in the 6A. You would have thou ght i would have worn it out by now but it is still going strong.. >>> >>> I hope your shoulder heals soon. >>> >>> >>> Denis Walsh >>> denis.walsh@comcast.net >>> >>> >>> >>>> On 20May, 2015, at 11:07, wrote: >>>> >>>> Interesting article in Flying mag (may) re dead stick landings. I expe rimented with determining that quite bit when I first got my 6A, based at L ZU at the time. That was in late 04/early 05. I never felt I could absolutl y put a number on it, but settled on 75/80 mph, pretty much speed on final. This article got me thinking about it again, but due to very recent rt shou lder surg, I will no be flying for a while. ( think I could manage everythin g exept flaps but getting in and especially back out may take a while). Anyw ay, would like to hear from 6A drivers what they would use for dead stick ai r speed? Charlie H >>>> >>>> >>>> >>>> This email has been checked for viruses by Avast antivirus software. >>>> www.avast.com >>>> >>>> >>>> >>>> >>>> class="">http://www.matronics.com/Navigator?RV-List >>>> class="">http://forums.matronics.com >>>> class="">http://www.matronics.com/contribution >>>> >>> >>> >>> >>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> st"">http://www.matronics.com/Navigator?RV-List >>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> //forums.matronics.com >>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> ot;">http://www.matronics.com/contribution >>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> >> >> >> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> st"">http://www.matronics.com/Navigator?RV-List >> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> //forums.matronics.com >> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> ot;">http://www.matronics.com/contribution >> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> > > 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > ________________________________ Message 2 _____________________________________ Time: 08:19:37 AM PST US From: Dave Gmail Subject: Re: RV-List: Best glide speed RV6A Hi Charlie, Look up CAFE foundation, they did a full review of the RV6 6A back in 1993. Regards Dave Burnham > On May 22, 2015, at 9:15 AM, Doug Gray wrote: > > Skylor, > Yes that is as I recall, I think the best glide angle speed corresponds to the tangent intercept drawn from the origin on the ROD plot. I will need to check my books to confirm. > I need to figure out the best way to test these. Also I don't think I coul d have flown my aircraft anywhere near smoothly enough during phase 1 to hav e collected useful data. > Thanks, > Doug > > Sent from my iPhone > >> On 22 May 2015, at 1:31 pm, Skylor Piper wrote: >> >> "Best glide" usually refers to best glide angle, i.e. the speed at which t he aircraft will cover the most distance for a given amount of altitude loss in still air. In engine out situations, this is usually what we're interes ted in because we want to go the most distance possible with the amount of a ltitude that we have. I believe best glide angle typically coincides with t he speed at which L/D is the greatest in still air. >> >> Best endurance is the speed at which the rate of descent is minimum. Thi s is useful for getting the most time possible for troubleshooting, but not n ecessarily traveling the greatest distance. Best endurance can occur at a s ignificantly lower airspeed than best angle, so while the rate of descent ma y be minimized, less forward progress is made per unit time resulting in a s teeper glide angle. >> >> Skylor >> >> Sent from my iPhone. >> >>> On May 21, 2015, at 6:54 PM, Doug Gray wrote: >>> >>> When discussing best glide I am never sure if we are talking about best g lide endurance or best glide range. Which do we use? >>> I have never tested these on my RV-6 but intend to do so now the engine h as a couple of hundred hours. If someone can point me to a recommended proce dure this would be helpful too. >>> Doug Gray >>> >>> Sent from my iPad >>> >>>> On 21 May 2015, at 9:18 am, Denis Walsh wrote : >>>> >>>> Charlie, I have a 6A, and I agree with your ball park figure; however I would caution there are many variables: prop (cs or fixed), power status (s topped prop or windmill), airplane weight, Idle rpm of your engine, etc. Th ere are probably more. >>>> >>>> In my case I have an average weight 180hp with c/s prop and low idle sp eed. I use 80 to 90 knots for glide and across the fence 75K. That leaves a lot of speed to kill in the flare but I have a low idle speed and lots of d rag if windmilling. This is what I practice with. It gives a rather steep g lide and I am sure it would be quite different with a stopped prop or parti al power, but I feel these would make for a better glide which I could deal w ith. I always practice with the prop in max RPM so I have max drag. >>>> >>>> One can practice for the zero thrust, min drag glide if you fiddle wit h the throttle to establish zero thrust, but I consider this to be too tough for me and of minimal value in an emergency which will almost certainly be d ifferent than you practiced any way! My opinion is the same about practicin g with coarse pitch glides. I don=99t think you can count on having e nough oil pressure to go coarse pitch in many engine failure scenarios. So I just practice the worst case, with low pitch low rpm, and glide at 80-90, u ntil the field is made then flare, add drag and land. I figure if my emerge ncy has better glide angle than I have practiced, I can put the flaps down s ooner or side slip. Coming up short on final is, on the other hand usually n ot a good option. >>>> >>>> I certainly don=99t claim this is the best or the only way to pra ctice, it=99 s just the way I do it, as you asked, based on a lot of p ractice over the past 18 years and 3100 hours in the 6A. You would have tho ught i would have worn it out by now but it is still going strong.. >>>> >>>> I hope your shoulder heals soon. >>>> >>>> >>>> Denis Walsh >>>> denis.walsh@comcast.net >>>> >>>> >>>> >>>>> On 20May, 2015, at 11:07, wrote: >>>>> >>>>> Interesting article in Flying mag (may) re dead stick landings. I exp erimented with determining that quite bit when I first got my 6A, based at L ZU at the time. That was in late 04/early 05. I never felt I could absolutl y put a number on it, but settled on 75/80 mph, pretty much speed on final. This article got me thinking about it again, but due to very recent rt shou lder surg, I will no be flying for a while. ( think I could manage everythin g exept flaps but getting in and especially back out may take a while). Anyw ay, would like to hear from 6A drivers what they would use for dead stick ai r speed? Charlie H >>>>> >>>>> >>>>> >>>>> This email has been checked for viruses by Avast antivirus software. >>>>> www.avast.com >>>>> >>>>> >>>>> >>>>> >>>>> class="">http://www.matronics.com/Navigator?RV-List >>>>> class="">http://forums.matronics.com >>>>> class="">http://www.matronics.com/contribution >>>>> >>>> >>>> >>>> >>>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D >>>> st"">http://www.matronics.com/Navigator?RV-List >>>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D >>>> //forums.matronics.com >>>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D >>>> ot;">http://www.matronics.com/contribution >>>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D >>>> >>> >>> >>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> st"">http://www.matronics.com/Navigator?RV-List >>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> //forums.matronics.com >>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> ot;">http://www.matronics.com/contribution >>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >>> >> >> >> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> st"">http://www.matronics.com/Navigator?RV-List >> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> //forums.matronics.com >> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> ot;">http://www.matronics.com/contribution >> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> > > > 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv-list Browse Digests http://www.matronics.com/digest/rv-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.