KR> ground effect and stall speed?
Does anybody know if ground effect lowers your stall speed? +++ I always believed that it did not, so I was surprised to read the compelling evidence from John M, viz., "Mine actually lifts off at 37 knots in ground effect and will fly a foot or so above the ground however stall at altitude is at about 42 knots". I suspect that the TAS does not change, but the IAS does due to the ground effect on airflow around the pitot. Would be interesting to hear from the KR that has the pitot on top of the Fin. For your purposes right now, I guess the best answer is yes - what you will see on the ASI will be lower in ground effect (compared to readings observed at altitude). What have you decided regarding the canopy latch and the turtle deck attachments? Good luck Steve J
KR> ground effect and stall speed?
At 05:57 PM 5/28/2005, you wrote: >Does anybody know if ground effect lowers your stall speed? I would think >so, at least some small amount, but I don't know for sure. If so, how much? Technically speaking, the stall speed decreases asymptotically to zero the closer you get to the ground but you will never see that in a practical case. The coefficient of lift does not continue to increase at the same rate and positive sink rate means you eventually come down. In the practical case, the stall speed will be as much as 1/2 the normal stall. That is one reason that you can lift off so far behind the power curve and not be able to climb out. Don Reid - donreid "at" peoplepc.com Bumpass, Va Visit my web sites at: AeroFoil, a 2-D Airfoil Design And Analysis Computer Program: http://aerofoilengineering.com KR2XL construction: http://aerofoilengineering.com/KR/KR2XL.htm Aviation Surplus: http://aerofoilengineering.com/PartsListing/Airparts.htm EAA Chapter 231: http://eaa231.org Ultralights: http://usua250.org VA EAA State Fly-in: http://vaeaa.org
KR> ground effect and stall speed?
Steve Jacobs wrote: > What have you decided regarding the canopy latch and the turtle deck > attachments? I think my latches will be OK, but their attachment to the canopy frame is still suspect. I plan to epoxy an aluminum angle over the edge of the frame and connect the latch to it, rather than to the "post" that I have running into the frame now. I'd been thinking about running two layers of glass tape from the decks down to overlap the top longeron, mainly to keep water out and air in, so if I locally (at each end) make them out of three layers of carbon fiber and screw them into bosses at each end (epoxied just below the longeron) I won't worry about them any more... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net --
KR> ground effect
I don't think you can >get this plane out of ground affect. >Daniel R. Heath Ground effect would be equal to approx 1/2 the wingspan. I doubt that there is an airplane flying that can land without experiencing ground effect. Larry Flesner
KR> ground effect
Larry wrote- >I doubt that there is an airplane flying that can land without >experiencing ground effect. Wilga and Storch ;o) Oscar Zuniga San Antonio, TX mailto: taildr...@hotmail.com website at http://www.flysquirrel.net
KR> ground effect
At 07:57 AM 5/26/05 -0500, you wrote: >Larry wrote- >>I doubt that there is an airplane flying that can land without >>experiencing ground effect. >--- >Wilga and Storch ;o) >Oscar Zuniga ++ I doubt that even their wing is higher than half their wingspan above the ground. Close maybe, with little effect, but with all their highlift devices, I doubt they would notice it anyway. Larry Flesner
KR> ground effect
Larry wrote- >I doubt that even their wing is higher than half their wingspan >above the ground. Close maybe Span on a Wilga is 36'-6", making the half-span (one wing) about 18'. Half that wingspan is about 9'. Take a look at the chap standing next to the one at http://www.kiwiaircraftimages.com/pages/wilga8.html . If he's 6' tall, that wing is very close to being 8' off the deck, so it's pretty darn close (but the tail still flies in ground effect in landing configuration). It's an amazing aircraft. Nothing here for KRs; sorry... I've used up my "Friday privileges" and will shut up now. Oscar Zuniga San Antonio, TX mailto: taildr...@hotmail.com website at http://www.flysquirrel.net
KR> ground effect
I don't believe that the wing span is the determining factor. Take a glider with a 23 meter (75ft) wing span, there is no way your are in ground effect at 12 m (37ft) of the ground. Wing span, cord length, wing loading and spead must be in the calculation (guessing). Not being an expert, and not needing to the scinentific reasons, just nowing how to use it and/or deal with it is all I need know. :-) regards Barry Kruyssen Cairns, Australia RAA 19-3873 k...@bigpond.com http://www.users.bigpond.com/kr2/kr2.htm - Original Message - From: larry flesner To: KRnet Sent: Thursday, May 26, 2005 11:04 PM Subject: Re: KR> ground effect At 07:57 AM 5/26/05 -0500, you wrote: >Larry wrote- >>I doubt that there is an airplane flying that can land without >>experiencing ground effect. >--- >Wilga and Storch ;o) >Oscar Zuniga ++ I doubt that even their wing is higher than half their wingspan above the ground. Close maybe, with little effect, but with all their highlift devices, I doubt they would notice it anyway. Larry Flesner
KR> ground effect
At 07:48 AM 5/27/2005 +1000, you wrote: >I don't believe that the wing span is the determining factor. Take a >glider with a 23 meter (75ft) wing span, there is no way your are in >ground effect at 12 m (37ft) of the ground. Wing span, cord length, wing >loading and spead must be in the calculation (guessing). > >Not being an expert, and not needing to the scinentific reasons, just >nowing how to use it and/or deal with it is all I need know. :-) Sorry, but in both my classes in Aero in college, and during my training as an airline pilot, ground effect starts at 1/2 the wing span. (Drag due to lift reduces by 1/2 at the 1/2 wing span height because the down flow off the aft part of the wing is cut off.) Larry Severson Fountain Valley, CA 92708 (714) 968-9852 lar...@socal.rr.com
KR> ground effect
Correct Larry David Mikesell 23597 N. Hwy 99 Acampo, CA 95220 209-609-8774 skyguy...@skyguynca.com www.skyguynca.com - Original Message - From: "larry severson" To: "KRnet" Sent: Thursday, May 26, 2005 8:43 PM Subject: Re: KR> ground effect > At 07:48 AM 5/27/2005 +1000, you wrote: > >I don't believe that the wing span is the determining factor. Take a > >glider with a 23 meter (75ft) wing span, there is no way your are in > >ground effect at 12 m (37ft) of the ground. Wing span, cord length, wing > >loading and spead must be in the calculation (guessing). > > > >Not being an expert, and not needing to the scinentific reasons, just > >nowing how to use it and/or deal with it is all I need know. :-) > > Sorry, but in both my classes in Aero in college, and during my training as > an airline pilot, ground effect starts at 1/2 the wing span. (Drag due to > lift reduces by 1/2 at the 1/2 wing span height because the down flow off > the aft part of the wing is cut off.) > > > Larry Severson > Fountain Valley, CA 92708 > (714) 968-9852 > lar...@socal.rr.com > > > ___ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html
KR> Ground effect
Larry I am gonna knock just alittle more dust off. Ground effect actually begins the height above the ground that equals the width of the wingspan, and is most pronounced at half the width of the wingspan (where we feel its effects the most). Ground effect for fixed wing aircraft is defined as the effect that the proximity to the ground has on the airflow patterns about an aircraft's wings. It effects ALL fixed wing aircraft regardless of engine or not, or wingspan length. It has the gradually increasing effect of "straightening" the airflow out over the wings reducing drag giving a performance increase with out the associated drag component that exists at altitude. BY canceling the wingtip vortices, which restores tip lift, and smoothing airflow over the rest of the wing, reducing drag the airplane gets this performance increase. For more on this see The Airplane Flying Handbook printed by ASA and available at nearly any pilot shop, Sportys, AS&S, King Schools, and more. And while you are at it, check out the Handbook of Aeronautical Knowledge also printed by ASA. It will remind all pilots of the basics and bring you up to speed if it has been awhile since you looked at the Regs etc... Colin Rainey Sanford, FL Almost all the Corvair parts in, ready to assemble Trailer gone with Jim Ferris to pickup his KR2S
KR> Ground effect
>Ground effect actually begins the height above the ground that equals the >width of the wingspan, and is most pronounced at half the width of the >wingspan (where we feel its effects the most). Ground effect for fixed >wing aircraft is defined as the effect that the proximity to the ground >has on the airflow patterns about an aircraft's wings. It effects ALL >fixed wing aircraft regardless of engine or not, or wingspan length. It >has the gradually increasing effect of "straightening" the airflow out >over the wings reducing drag giving a performance increase with out the >associated drag component that exists at altitude. BY canceling the >wingtip vortices, which restores tip lift, and smoothing airflow over the >rest of the wing, reducing drag the airplane gets this performance >increase. For more on this see The Airplane Flying Handbook printed by >ASA and available at nearly any pilot shop, Sportys, AS&S, King Schools, >and more. And while you are at it, check out the Handbook of Aeronaut That is why much of the early part of the flight of the Voyager around the world flight was down next to the water. However, the 1/2 figure is where pilots first notice the effect. Larry Severson Fountain Valley, CA 92708 (714) 968-9852 lar...@socal.rr.com
KR> Ground effect
Not many of you are old enough to remember a gentleman named Max Conrad who set many long distance records in the 50's and 60's. He claimed to have achieved these long distance flights by flying only a few feet above the sea and staying in ground (sea) effect. Must have worked OK for him. John Sickafoose Naples, Fl
KR> ground effect and stall speed?
Does anybody know if ground effect lowers your stall speed? I would think so, at least some small amount, but I don't know for sure. If so, how much? Thanks, Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net --
KR> ground effect and stall speed?
Hi Mark Mine actually lifts off at 37 knots in ground effect and will fly a foot or so above the ground however stall at altitude is at about 42 knots. I try not to rotate and climb until about 55 -60 knots and I figured if it climbs out at that then I can safely approach using the same numbers in my earlier flights. any slower and the nose gets really high affecting visibility. John The Martindale Family 29 Jane Circuit TOORMINA NSW 2452 AUSTRALIA phone: 61 2 66584767 email: johnja...@optusnet.com.au - Original Message - From: "Mark Langford" To: "KRnet" Sent: Sunday, May 29, 2005 7:57 AM Subject: KR> ground effect and stall speed? > Does anybody know if ground effect lowers your stall speed? I would think so, at least some small amount, but I don't know for sure. If so, how much? > > Thanks, > > Mark Langford, Huntsville, Alabama > see KR2S project N56ML at http://home.hiwaay.net/~langford > 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 krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html
KR> ground effect and stall speed?
Mine would normally stall around 45 MPH at altitude. I have tried to stick the tail on landing before at 35 indicated feeling sure that it was way below stall speed and it just climbed right on up. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -Original Message- From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net]On Behalf Of Mark Langford Sent: Saturday, May 28, 2005 5:57 PM To: KRnet Subject: KR> ground effect and stall speed? Does anybody know if ground effect lowers your stall speed? I would think so, at least some small amount, but I don't know for sure. If so, how much? Thanks, Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford 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 krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
KR> ground effect and stall speed?
At 04:57 PM 5/28/2005 -0500, you wrote: >Does anybody know if ground effect lowers your stall speed? I would think >so, at least some small amount, but I don't know for sure. If so, how much? No, only drag. Larry Severson Fountain Valley, CA 92708 (714) 968-9852 lar...@socal.rr.com
