---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Tue 01/09/18: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:08 AM - Re: Are Vne and Va IAS or TAS? (William Daniell) 2. 04:36 AM - Fuel Inlet Pipe repacement on 914 XS (willydewey) 3. 09:34 AM - Re: Are Vne and Va IAS or TAS? (Pete) 4. 04:02 PM - Re: Fuel Inlet Pipe repacement on 914 XS (Tim Ward) ________________________________ Message 1 _____________________________________ Time: 04:08:51 AM PST US From: William Daniell Subject: Re: Europa-List: Are Vne and Va IAS or TAS? Bud thanks, sets my mind at rest. William Daniell LONGPORT +57 310 295 0744 On Sun, Jan 7, 2018 at 11:09 PM, Bud Yerly wrote: > Will, > I'm still on the road but here goes. > Short answer: > Q is force, whereas True is just speed. > Long Answer: > Think of it this way. The mono cruises at 175 TAS at 18,000 with a 914. > The indicated is only 125 ish. You cannot pull enough G to achieve 6 Gs > before you stall or have a vertical gust break the plane. Is the mono abo ve > VNE, at 175 TAS, NO. Heck you are not at Vno or about 131 KIAS which is > your green arc for gust factor(turbulent speed). > > That gust factor is what you need to be aware of in the turbulence of the > mountains. > > "Aircraft Performance" by Domash explains it. > So does the FAA. For finding high speed affects, the USAF F104 VN diagra m > is on Wikipedia and shows how Mach affects figure in for high TAS. > > TAS is important in turn rate, radius, navigation, and determining your > Mach and Q velocity. But it is your Q (dynamic pressure), aka IAS, that > affects, flutter, structural deformation, and your stall and not to exce ed > speeds. This means what you read on your airspeed indicator is what you > need to know for the plane. TAS and Ground Speed affect your pilotage > which is a different topic. > > Again, in mountain flying, you need to know your turn diameter when valle y > flying, high altitude patterns (wider pattern necessary), lead turns to a > radials etc. (especially In high speed aircraft) and in light aircraft in > very high elevations. Engine performance vs airspeed bleed off becomes a > factor as well. > > Regards, > > Bud Yerly > Custom Flight Creations > > > From: William Daniell > Sent: Friday, January 5, 4:07 PM > Subject: RE: Europa-List: Are Vne and Va IAS or TAS? > To: europa-list@matronics.com > > > Bud > Does this apply even at the upper altitude range ....say 13k or 15k? > Will > > > On Jan 4, 2018 22:19, "Bud Yerly" @msn.com > > wrote: > > Yep Graham, > Airplanes only feel air pressure, not the velocity of the molecule alone. > Dynamic pressure is =C2=BD Density times Velocity Squared or IAS (actua lly you > have calibrated then equivalent) is what the airplane feels. Those RV gu ys > got all hung up on this and confused everyone. > > Bottom line, what you read on the airspeed indicator counts. TAS is > important (actually Mach number) as the skin heats up due to friction whi ch > is a different ball of wax. I was always a slow speed aero guy to match my > mind. > > Regards, > Bud Yerly > > > Sent from Mail > > for Windows 10 > > *From:* owner-europa-list-server@matronics.com matronics.com> on behalf of Pete > @zutrasoft.com > > *Sent:* Thursday, January 4, 2018 5:49:37 PM > > *To:* europa-list@matronics.com > *Subject:* Re: Europa-List: Are Vne and Va IAS or TAS? > > Hi Ivan, just to confirm, Vd IAS @8000ft DA? > > Thanks again! > Pete > > On Jan 4, 2018, at 5:21 PM, > @btinternet.com > @btinternet.com > wrote : > > All our company aircraft were tested to Vd, 10% over Vne. And not just > taken to the speed but then tested [short stick and rudder raps] to see i f > any flutter mode could be excited at Vd. I have performed these tests at/ up > to 8000ft . We have never experienced any flutter mode. I also tested the > tail plane underbalanced and over balanced with the same results. To my > knowledge we have not had any reported flutter incidence on the entire > fleet. As you mentioned Pete did exceed Vd on a few occasions. > > Ivan > > ________________________________ Message 2 _____________________________________ Time: 04:36:12 AM PST US Subject: Europa-List: Fuel Inlet Pipe repacement on 914 XS From: "willydewey" I am considering replacement of the rubber connector from the tank to the cobra fitting.. Engineering suggest that the existing rubber pipe requires inspection before the next flight. My anxiety is squeezing or removing this item will destroy it in any event hence the need to order an aluminium tube and connecting rubbers ASAP I gather someone is taking orders for the tube for delivery from NZ and the rubbers are from Tim Ward. I would like to be included in these bulk orders. willydewey@gmail.com Bill Dewey G-IANI -------- Give a wise man knowledge and he will be yet wiser Read this topic online here: http://forums.matronics.com/viewtopic.php?p=477195#477195 ________________________________ Message 3 _____________________________________ Time: 09:34:00 AM PST US From: Pete Subject: Re: Europa-List: Are Vne and Va IAS or TAS? Not to be argumentative, but as i understand it, Bud's explanation ignores t he issue reported/described in the other articles, namely that at altitude t here is less flutter damping for the same reasons Bud explains wrt the struc tural limits. So for flutter specifically it is TAS that is the determining limit, and not IAS. Taken to the extreme, the U2 sometimes operates near " coffin corner" where flutter speed is very near stall speed (IAS is indicati ng near stall, but they are so high and the air so thin that they are near t he risk of flutter). It is also why the http://www.perlanproject.org/ glide r is heavily instrumented to detect the onset of flutter as they go higher a nd higher in their record attempts. Taht said, it is comforting to know that Ivan has tested Vd with stick excit ation to 8000 feet, so i would assume that this could be used as the deratin g baseline when going to higher TAS's. Cheers, Pete A239 > On Jan 9, 2018, at 7:08 AM, William Daniell w rote: > > Bud thanks, sets my mind at rest. > > William Daniell > LONGPORT > +57 310 295 0744 > >> On Sun, Jan 7, 2018 at 11:09 PM, Bud Yerly wrote: >> Will, >> I'm still on the road but here goes. >> Short answer: >> Q is force, whereas True is just speed. >> Long Answer: >> Think of it this way. The mono cruises at 175 TAS at 18,000 with a 914. The indicated is only 125 ish. You cannot pull enough G to achieve 6 Gs be fore you stall or have a vertical gust break the plane. Is the mono above VN E, at 175 TAS, NO. Heck you are not at Vno or about 131 KIAS which is your g reen arc for gust factor(turbulent speed). >> >> That gust factor is what you need to be aware of in the turbulence of the mountains. >> >> "Aircraft Performance" by Domash explains it. >> So does the FAA. For finding high speed affects, the USAF F104 VN diagra m is on Wikipedia and shows how Mach affects figure in for high TAS. >> >> TAS is important in turn rate, radius, navigation, and determining your M ach and Q velocity. But it is your Q (dynamic pressure), aka IAS, that affec ts, flutter, structural deformation, and your stall and not to exceed speed s. This means what you read on your airspeed indicator is what you need to k now for the plane. TAS and Ground Speed affect your pilotage which is a dif ferent topic. >> >> Again, in mountain flying, you need to know your turn diameter when valle y flying, high altitude patterns (wider pattern necessary), lead turns to a r adials etc. (especially In high speed aircraft) and in light aircraft in ver y high elevations. Engine performance vs airspeed bleed off becomes a facto r as well. >> >> Regards, >> >> Bud Yerly >> Custom Flight Creations >> >> >> >> From: William Daniell >> Sent: Friday, January 5, 4:07 PM >> Subject: RE: Europa-List: Are Vne and Va IAS or TAS? >> To: europa-list@matronics.com >> >> >> Bud >> Does this apply even at the upper altitude range ....say 13k or 15k? >> Will >> >> >>> On Jan 4, 2018 22:19, "Bud Yerly" wrote: >>> Yep Graham, >>> Airplanes only feel air pressure, not the velocity of the molecule alone . Dynamic pressure is =C2=BD Density times Velocity Squared or IAS (actua lly you have calibrated then equivalent) is what the airplane feels. Those R V guys got all hung up on this and confused everyone. >>> >>> Bottom line, what you read on the airspeed indicator counts. TAS is imp ortant (actually Mach number) as the skin heats up due to friction which is a different ball of wax. I was always a slow speed aero guy to match my mind .. >>> >>> Regards, >>> Bud Yerly >>> >>> >>> Sent from Mail for Windows 10 >>> >>> From: owner-europa-list-server@matronics.com on behalf of Pete >>> Sent: Thursday, January 4, 2018 5:49:37 PM >>> >>> To: europa-list@matronics.com >>> Subject: Re: Europa-List: Are Vne and Va IAS or TAS? >>> >>> Hi Ivan, just to confirm, Vd IAS @8000ft DA? >>> >>> Thanks again! >>> Pete >>> >>> On Jan 4, 2018, at 5:21 PM, wrote: >>>> All our company aircraft were tested to Vd, 10% over Vne. And not just t aken to the speed but then tested [short stick and rudder raps] to see if an y flutter mode could be excited at Vd. I have performed these tests at/up to 8000ft . We have never experienced any flutter mode. I also tested the tail plane underbalanced and over balanced with the same results. To my knowledg e we have not had any reported flutter incidence on the entire fleet. As you mentioned Pete did exceed Vd on a few occasions. >>>> >>>> Ivan > ________________________________ Message 4 _____________________________________ Time: 04:02:36 PM PST US Subject: Re: Europa-List: Fuel Inlet Pipe repacement on 914 XS From: Tim Ward Hi Bill, The aluminium elbow I distribute is for the XS both Monowheel and Tri Gear. It also can be used for the Monowheel Classic which has incorporated the Baggage Mod and MTOW increase. It connects with the white plastic cobra from the fuel inlet, supplied by the XS Kit, replacing the rubber elbow, to the tank inlet. I can put you on the list. Once a UKLAA Mod. approval is reached and the cost is of production is agreed upon, then I shall let you know. Cheers, Tim Tim Ward 12 Waiwetu Street, Fendalton, Christchurch, 8052 New Zealand ward.t@xtra.co.nz Mob +64 210640221 > On 9/01/2018, at 4:35 AM, willydewey wrote: > > > I am considering replacement of the rubber connector from the tank to the cobra fitting.. Engineering suggest that the existing rubber pipe requires inspection before the next flight. > My anxiety is squeezing or removing this item will destroy it in any event hence the need to order an aluminium tube and connecting rubbers ASAP > I gather someone is taking orders for the tube for delivery from NZ and the rubbers are from Tim Ward. I would like to be included in these bulk orders. > willydewey@gmail.com > Bill Dewey G-IANI > > -------- > Give a wise man knowledge and he will be yet wiser > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=477195#477195 > > > > > > > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message europa-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Europa-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/europa-list Browse Digests http://www.matronics.com/digest/europa-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.