---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Thu 10/13/11: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:40 AM - Re: Re: Landing RV-8 (Dale Ensing) ________________________________ Message 1 _____________________________________ Time: 04:40:34 AM PST US Subject: Re: RV-List: Re: Landing RV-8 From: Dale Ensing Well said Bob and I second that! Thank you Kevin for your contribution to t he RV crowd over the years. Dale Ensing RV-6A Sent from my iPhone On Oct 12, 2011, at 20:41, "bcollinsrv7a@comcast.net" wrote: > Just a note to say I think I learn more about flying airplanes from Kevin H orton than anyone I know, and just wanted to thank him publicly for outstand ing information. > > Do not archive > > Connected by DROID on Verizon Wireless > > > -----Original message----- > From: Kevin Horton > To: rv-list@matronics.com > Sent: Wed, Oct 12, 2011 23:01:11 GMT+00:00 > Subject: Re: RV-List: Re: Landing RV-8 > > > Two comments: > > 1. Each homebuilt aircraft has its own, individual ASI instrument error an d static system position error. The sum of these errors may be more than 10 k t on some aircraft. Thus the final approach IAS that is perfect for one airc raft may be completely wrong on another aircraft. Be careful taking someone e lse's numbers as the gospel and assuming that they will work for you in your aircraft. > > 2. The 1.3 Vso "rule" is not universally correct. Large aircraft have hist orically used an approach speed of 1.3 times the stall speed, with both spee ds measured in calibrated airspeed, not indicated airspeed (there has been a recent change to 1.23 times the stall speed, but they changed the way the s tall speed is measured, so the approach speeds haven't really changed). Most aircraft have large static source position errors at the stall speed, and t he sense of the usual error is to make the indicated speed lower than the ca librated speed. I used to fly a C182 that had a ridiculously low indicated a irspeed at the stall. If I were to fly final at 1.3 times the indicated stal l speed I would be much too slow in that aircraft, and would risk having a h ard landing if there was the slightest wind gust. > > We need to keep in mind that this 30% margin over the stall speed is actua lly quite a few knots on a big aircraft, as the stall speed is fairly high. B ut 30% of a 50 mph stall speed is a much smaller margin than 30% of a 100 mp h stall speed. A 20 mph wind gust will cause both aircraft to lose 20 mph o n final, so the smaller aircraft may need more than 30% speed margin to allo w for the gusts. > > In my opinion, the best way to figure out the best approach speed for your aircraft is to simply try approaches at ever slower speeds on a calm day. R educe the approach speed by one or two mph each time. The plane will talk to you, and you'll figure out where the lowest practical approach speed is. No w, for "every day" flying, you should add a small buffer above the demonstra ted lowest practical approach speed, to allow for a bit of pilot inattention , or minor wind gusts. In flight testing, we have to demonstrate that the ai rcraft can be landed safely when the approach speed is 5 kt less than the re commended one. Operators typically add another 5 kts over the recommended sp eed, so they are actually flying 10 kt faster than was shown to be safe duri ng flight testing. > > And of course if the winds are gusting, you all know you need to add even m ore speed. > > And we know that you need a higher approach speed at higher weights. And w e also know that the stall speed (and thus the required approach) is higher a t forward CG than it is at aft CG. Note: the aircraft will handle differentl y at forward and aft CG, and these handling changes may require different ap proach speeds at different CGs. > > -- > Kevin Horton > RV-8 > Ottawa, Canada > http://www.kilohotel.com/rv8 > > > On 2011-10-12, at 17:58 , Scott wrote: > > > Doesn't 80 knots sound a bit fast? With listed stall speeds of 51-58 MP H, I would expect final to be at about 60-65 knots (1.3 X Vso)??? Of course, one has to take into account any gusts, etc.... > > > > > > > > On 10-12-2011 17:09, Matt Tucciarone wrote: > >> Thanks Bill and others who have been commenting. > >> > >> I did get some time in a Citabria before going to the rv and it is simi lar. Just a little slower on approach. I have been coming in around final at around 80 knots. > >> > >> The best landing I have made to date was a tail low wheel landing. > >> > >> Hopefully soon I will get the hang of this > >> > >> Bill Judge wrote: > >> > > > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > > > )=89-=C3=8A=EF=AC=82=C2=A2{l=C3=A37=88=82r=C3=A2h=C3=98M4=9D M=1Fi=C2=AB=C3=BA=C2=A2=C3=8D=9Az=CF=EF=AC=81=C2=A1 .=C3=86'=C2=B4N =17=C3=ABT=88=8F=C2=A8=C2=A5I=C3=B6=C3=A4Qh=C3=86=C3=88=C3=AE=C2=B1=C3=8E ax=88=86=89-=C3=86=C3=A2=9Ar=C2=AC=9A=89=A4=94^ j=82=AC=C2=B4z=88=9AZ=C3(=1A=88=82=C3=A4=C3=8C=C2=B0=88=AB=C3 =8B=C2=AC=C2=AB=89-=C3'=C3=88=C3=B6=C3=BC"=9A=89=A4=82=AC =89-=C3=A4X=89-=C3=A2=C3=8E,=CF=C2=BBZ=88=9E=88=8F=C2=A8=C2 =B5I=CB=87J=C3=8A=C3=8Fr=88=8F=C2=A9=88=82*'=02=88=91!=C3=A4=CB=9C=C3 =ADy=84=A2=B9=C3=91:0=C3=BBZ=1Aw=88=9E=81=84=C2=BB=1A=C3=8B=C2 =AC=C2=AB=C3=87=C3'=C2=B4E=01=03=C2=B7=C2=A2=81=84,=C3'=84=A2=EF=AC =81jwf=CF=C2=BBf=CF=C2=BBf=C2=A2=88=91=C3=B6=C3=9C=88=91=C3=BC=C3 =9C=82=ACi=CB=87=C2=B80=C2=ACf=89-=C3=86=C3=A2=9Ar=C2=AB(=C3=B5 =C3=9BZ=C3(=1A=88=82=C3=A4=94T=88=8F=C2=A8=88=82=1Bm=C3=9F =CB=87=EF=A3=88=9A =C3=B6=88=82=88=AB'=C3=A2=C3=1C=C2 =A2o=C3-j=C2=AF-j=81=84+ER=9A=89=A4=EF=AC=82=81=840 =04=948=9C=02Ia=01=14=B0T1$=C3=B6=C3=B4=C3=8B+y=C2=B4\=C2=A2 {^=C3=BB=C3=B7=A2=89=A4=C3=9C=C3=98j)ZnW=C3=98=C3=A2=C2=B4ayg=C3=B5 =16=C3=A4=C3=93=C3=B6=88=86=C2=B0=89-=C3=81=C2=B7=88=82=81=84=7F =CB=9D=CB=99+=88=ABk&j=81=84=C3=8B=C3=BB',r=C3=A2=C2=B0=88=82=81 =84=7F=CB=9D=CB=99+=88=ABk&j=81=84=C3=8B=C3=BB',r=C3=A2=C3=B8h=88=8F =C2=A8=C2=A5*'=88=82=88=8F=C3=B5=88=AB=C3=C2=AE=C3=B9g=C3=B5J+^N =16=C3=9F=C3=AC*.~=C3=A4=C3=9A=C2=A2=C3=8D=A1zw=C2=B4=C2=A2=C3=8E,=88 =AB=C3=B6h=C3=86=9D=1A=88=82=93=C3=8EjY^.+-=01=C5=B8=C2=A2=C3 =B9=C2=AEky=C2=AFm=88=82=C3=BC=CB=87=88=9A=0C&j=81=84=C3=8B=C3=BB', r=C3=A2=C3=B8r=C3=A2=C3=8C=C3=86&=C3=93=88=82*'=C3=9C=82=ACi=CB=87=C2=B8 0=C2=ACf=89-=C3=86=C3=A2=9Ar=C2=AB(=C3=B5=CB=9C(=C3=BB=81=84 =9An=C3=8Eb=C2=A2=7F=81=84=CB=9D=C3=B8=EF=AC=82=C2=A2{=7F=C2=B6=88=91 =C3=B8n=C3=A1r=CB=9B=1Bf ------------------------------------------------------------------------------------- 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.