---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Mon 07/01/13: 26 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:56 AM - Re: Re: wing lift/drag pins (houlihan) 2. 01:29 AM - Re: Gumpy visits Wales (& there be dragons Kevin) (Carl Pattinson) 3. 01:55 AM - Re: Re: wing lift/drag pins (Roger Sheridan) 4. 02:41 AM - Re: wing lift/drag pins (Alan Carter) 5. 06:31 AM - Re: where to locate fuel pressure sensor (richard) 6. 06:54 AM - Re: Fuel tank sensor opening problem (richard) 7. 07:22 AM - SV: Re: wing lift/drag pins (Sidsel & Svein Johnsen) 8. 07:29 AM - Re: Fuel tank sensor opening problem (Fred Klein) 9. 07:37 AM - Re: SV: Re: wing lift/drag pins (Frans Veldman) 10. 07:43 AM - Re: Fuel tank sensor opening problem (Frans Veldman) 11. 07:53 AM - Re: SV: Re: wing lift/drag pins (GRAHAM SINGLETON) 12. 08:05 AM - Re: Fuel tank sensor opening problem (Bob Harrison) 13. 08:14 AM - Re: Re: wing lift/drag pins (Frans Veldman) 14. 08:24 AM - SV: SV: Re: wing lift/drag pins (Sidsel & Svein Johnsen) 15. 08:37 AM - SV: Re: wing lift/drag pins - ADDITION (Sidsel & Svein Johnsen) 16. 09:23 AM - Re: SV: SV: Re: wing lift/drag pins (Raimo Toivio) 17. 09:49 AM - Re: SV: SV: Re: wing lift/drag pins (Frans Veldman) 18. 10:00 AM - SV: SV: SV: Re: wing lift/drag pins (Sidsel & Svein Johnsen) 19. 10:05 AM - Water ballast (andrew cullum) 20. 10:36 AM - Re: wing lift/drag pins (Alan Carter) 21. 10:49 AM - SV: SV: SV: Re: wing lift/drag pins (Sidsel & Svein Johnsen) 22. 03:25 PM - Re: wing lift/drag pins (rparigoris) 23. 03:54 PM - Re: wing lift/drag pins (Alan Carter) 24. 11:01 PM - Official Europa-List FAQ (Frequently Asked Questions) (Matt Dralle) 25. 11:06 PM - Official Europa-List Usage Guidelines (Matt Dralle) 26. 11:23 PM - SV: Re: wing lift/drag pins (Sidsel & Svein Johnsen) ________________________________ Message 1 _____________________________________ Time: 12:56:53 AM PST US Subject: Re: Europa-List: Re: wing lift/drag pins From: houlihan Hi Alan. A few comments, 1, wings that have been demonstrated to fly OK for many thousands of hours do not usualy fail in normal flight , it should only happen in extreme circumstances so forget about your 1 "G" straight and level situation. 2, your comments about the WW2 bomber do not demonstrate failure due to aerodynamic loading., During the bomb release phase of flight it would be in 1"G" straight and level flight. the failure occurred because the fuselage holding the wings apart was removed allowing them to react as you describe. 3, there are lots of things in life I do not understand like high energy physics and brain surgery but when people who know about these things try and explain to me I try to listen and learn. you seem to have rejected all the explanations put forward by knowledgeable contributors to this forum. So when you find the answer from other sources please let us know the outcome so that we can all learn something. 4, If a Cessna 150 was over stressed in a high "G" maneuver to the extent that the mainplanes failed they would also fold forwards and upwards probably outboard of the struts.. Tim On 1 July 2013 01:01, Alan Carter wrote: > > > > Hi Graham. > I understand a little in what you a saying. > In the tail slip the wing is falling backwards to normal flight condition. > The pin would stop the wing from pulling out. > > But in normal level flight i see this bar in compression. > At this moment in time, i just can not see how you would get a forward > force. > > I find Europa.s notes mentioning words like "tie bar", > but i find many of Europa,s notes not to clear as to exactly what the > situation is. > > I think this bar is say, in compression 90% of the time and 10% in tension > some of the time, hence the pin. > But what the hell do i know, but im not giving up yet. > > Need a little micro transducer between the front wing root to see which > the bios is. > > Best Regards. > Alan > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=403665#403665 > > ________________________________ Message 2 _____________________________________ Time: 01:29:00 AM PST US From: "Carl Pattinson" Subject: RE: Europa-List: Gumpy visits Wales (& there be dragons Kevin) Talybont used to be owned by Bill Wynn, one of our first Europa builders and past Europa Club chairman (for many years). There was always a welcome for Europa owners wanting to drop in for a cup of tea and a chat. Don't have his contact details any more but might be in Pooleys or the farm strip guide. Many in the Europa community knew Bill well and may still be in contact. -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of graeme bird Sent: 30 June 2013 16:11 Subject: Europa-List: Gumpy visits Wales (& there be dragons Kevin) Some great views yesterday approaching Welshpool over Church Stretton, Long Mynd and then west to the coast at Aberdovey. Turned back before Talybont - anyone landed there? Look you though; there were hills, and clouds. Been thinking about the stopping the prop discussion. Gliders also like the hills, threatening clouds and thermal weather. Things we power pilots all seem to shy away from. -------- Graeme Bird G-UMPY Mono Classic/XS 912S/Woodcomp 3000/3W Newby: 75 hours 18 months g(at)gdbmk.co.uk Read this topic online here: http://forums.matronics.com/viewtopic.php?p=403650#403650 Attachments: http://forums.matronics.com//files/dsc03443_1_145.jpg ________________________________ Message 3 _____________________________________ Time: 01:55:34 AM PST US From: Roger Sheridan Subject: Re: Europa-List: Re: wing lift/drag pins Surely in gliding flight the wings must be pulling the fuselage forwards..........otherwise you would stop! On 1 Jul 2013, at 08:55, houlihan wrote: > Hi Alan. > > A few comments, > 1, wings that have been demonstrated to fly OK for many thousands of hours do not usualy fail in normal flight , it should only happen in extreme circumstances so forget about your 1 "G" straight and level situation. > > 2, your comments about the WW2 bomber do not demonstrate failure due to aerodynamic loading., During the bomb release phase of flight it would be in 1"G" straight and level flight. the failure occurred because the fuselage holding the wings apart was removed allowing them to react as you describe. > > 3, there are lots of things in life I do not understand like high energy physics and brain surgery but when people who know about these things try and explain to me I try to listen and learn. you seem to have rejected all the explanations put forward by knowledgeable contributors to this forum. So when you find the answer from other sources please let us know the outcome so that we can all learn something. > > 4, If a Cessna 150 was over stressed in a high "G" maneuver to the extent that the mainplanes failed they would also fold forwards and upwards probably outboard of the struts.. > > Tim > > > On 1 July 2013 01:01, Alan Carter wrote: > > Hi Graham. > I understand a little in what you a saying. > In the tail slip the wing is falling backwards to normal flight condition. > The pin would stop the wing from pulling out. > > But in normal level flight i see this bar in compression. > At this moment in time, i just can not see how you would get a forward force. > > I find Europa.s notes mentioning words like "tie bar", > but i find many of Europa,s notes not to clear as to exactly what the situation is. > > I think this bar is say, in compression 90% of the time and 10% in tension some of the time, hence the pin. > But what the hell do i know, but im not giving up yet. > > Need a little micro transducer between the front wing root to see which the bios is. > > Best Regards. > Alan > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=403665#403665 > > > > > > > > ========== > target="_blank">http://www.matronics.com/Navigator?Europa-List > ========== > http://forums.matronics.com > ========== > le, List Admin. > ="_blank">http://www.matronics.com/contribution > ========== > > > > > > > ________________________________ Message 4 _____________________________________ Time: 02:41:37 AM PST US Subject: Europa-List: Re: wing lift/drag pins From: "Alan Carter" Hi Bob. Thats seem,s reasonable , and a windmill goes round, So dose that mean a wing in flight is contributing or generating forward thrust. Tim. What you are saying to me, is, i don,t have the right to ask questions or challenge a reply. I accept there a fare more knowledgeable contributors than me on the forum. But i am still part of it and have the right to reply and ask, why or how dose this occur. I accept wings don,t fall off in normal flight, and this pin is probably for abnormal flight conditions, But if you go back to the beginning of this topic, it indicated to me the in level flight the wing provided some forward force, ie helping the propeller to pull the plane alone. Maybe it does , as Bob said about the glider, so this bar is in tension all the time if in the glide. or may be its in tension only some of the time, I don,t know, Regard . Alan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=403683#403683 ________________________________ Message 5 _____________________________________ Time: 06:31:06 AM PST US From: "richard" Subject: Re: Europa-List: where to locate fuel pressure sensor Hi Rowland I along with most agree that the eye watering prices charged for Rotax parts is scandalous but here I am sure you have asked for the wrong part . However if you would like it I can copy my fuel system layout and send it to you , I have completed 45hrs to date with no problems, if you do then contact me off line at rcollings@talktalk.net . Regards Richard -----Original Message----- From: Rowland Carson Sent: Friday, June 21, 2013 6:04 PM Subject: Re: Europa-List: where to locate fuel pressure sensor On 13 Jun 2013, at 12:13, richard wrote: > new rotax engines are supplied with just such a manifold, contact Conair > for a price Richard - I spoke with Conair and although I wasn't able to identify _all_ the part numbers for the fuel manifold, the total for those I found came to 578.55 sterling so I think I will be seeking cheaper options! > For what its worth I modified the fuel pipe runs, dispensing with the > rubber pipes in favour of proper aircraft aluminium see Mod No 13304 Where can I find info on Mod 13304? It doesn't appear on the LAA website anywhere I can find. I checked the list of all prototype mods (which only shows up to Mod 12403 for Europas) and the list of Standard Mods for Europas. in friendship Rowland | Rowland Carson ... that's Rowland with a 'w' ... | http://www.rowlandcarson.org.uk | Skype, Twitter: rowland_carson Facebook: Rowland Carson | pictures: http://picasaweb.google.com/rowlandcarson ________________________________ Message 6 _____________________________________ Time: 06:54:15 AM PST US From: "richard" Subject: Re: Europa-List: Fuel tank sensor opening problem Hi Frans I suggest you contact LAA and ask them for a copy of Mod 10602 which Ian Rickard had approved. This mod introduces a flange plate and seal assembly into the top of the tank. The important thing is that the flange seal is on the inside of the tank so no fuel contacts the out side or the cut edge. Hope this helps Regards Richard Europa xs Tri-gear 45hrs -----Original Message----- From: Frans Veldman Sent: Thursday, June 20, 2013 2:36 PM Subject: Europa-List: Fuel tank sensor opening problem Dear friends, In my fuel tank I have cut two small openings for fuel sensors. Serious fuel leaks started to develop, so I have removed the sensors to have a look. What I discovered is that in the area around the cut outs the tank wall has become swollen and seriously distorted. I remember some discussion on this forum about the treatment the fuel tank received, that this treatment was only on the surface and once you cut a hole in the tank the fuel can reach the unprotected material. I tank mogas and the ethanol in it doesn't help either. The question is now, what should I do? Is there any way to rescue the affected material, or should I cut it out? If I cut out the area, I have a new cut and will face the same problem but on a larger scale, unless there is some way to treat the newly cut opening. If I make a new cut, how can I prevent it from happening again? Of course, replacement of the fuel tank is something I want to avoid at all costs (and even then, I want to have fuel sensors in the new tank so I will have to deal with the same problem anyway). Is there any quick fix possible? This is the flying saison and I don't want to spoil it if there is a way to postpone a more long lasting repair until the winter. Thanks in advance for some great ideas, Frans ________________________________ Message 7 _____________________________________ Time: 07:22:10 AM PST US From: "Sidsel & Svein Johnsen" Subject: SV: Europa-List: Re: wing lift/drag pins This has been an interesting discussion, but it appears to me that it got off-track somewhere because "forward" has two meanings (see the attached illustrations): (i) The LIFT does not have a "forward" component, under any circumstances, if FORWARD means the direction of the aircraft's flight. Reason: LIFT is by definition always perpendicular to the direction of flight, as DRAG is always opposite to the direction of flight (i.e. perpendicular to the LIFT). (ii) If, however, one refers to FORWARD as the direction of the aircrafts centerline, then LIFT has a "forward" component as soon as the centerline points up at the nose relative to the direction of flight. The higher the nose points up, the greater this forward component is. At some point it may, as I read the discussion, become larger than the wing DRAG's component parallel to the centerline in the opposite direction, giving a net "forward" force on the wing. (iii) The LIFT does not contribute, under any circumstances, to moving the aircraft forward through the air, as there is no lift component parallel to the direction of flight. A glider is "propelled" by the forward - in the direction of flight - component of the aircraft's WEIGHT only. Regards, Svein LN-SKJ ________________________________ Message 8 _____________________________________ Time: 07:29:51 AM PST US From: Fred Klein Subject: Re: Europa-List: Fuel tank sensor opening problem On Jul 1, 2013, at 6:53 AM, richard wrote: > Hi Frans > I suggest you contact LAA and ask them for a copy of Mod 10602 which Ian Rickard had approved. This mod introduces a flange plate and seal assembly into the top of the tank. The important thing is that the flange seal is on the inside of the tank so no fuel contacts the out side or the cut edge. Hope this helps > Regards Richard > Europa xs Tri-gear 45hrs All, Though still just a the builder, I'm following this topic w/ keen interest and full sympathy for flyers who are experiencing fuel tank leaks and deformation. When I read about the introduction of tank mods such as #10602, am I correct in assuming that work of this nature is done AFTER slicing off the top of the CM, say, 1/2 inch down from the top flat surface?...or perhaps after slicing off one of the head rests, say 1/2 inch up from the top flat surface of the CM? Also...long ago I installed the Europa capacitance fuel gauge PRIOR to installing the tank in the CM. (At the time I was astounded to read the instructions' claim that it is possible to install the gauge AFTER installing the CM by working thru the access hole in the side of the head rest...I salute anyone who managed to do that!) If I recall correctly, the installation included an internal flange plate which I now surmise should prevent fuel contacting the cut edge...much appreciation if anyone can confirm this. Fred A-194 ________________________________ Message 9 _____________________________________ Time: 07:37:02 AM PST US From: Frans Veldman Subject: Re: SV: Europa-List: Re: wing lift/drag pins On 07/01/2013 04:21 PM, Sidsel & Svein Johnsen wrote: > This has been an interesting discussion, but it appears to me that it > got off-track somewhere because "forward" has two meanings (see the > attached illustrations): How does an autogyro (autocopter?) work? What is causing the blades to move forward? > A glider is > propelled by the forward in the direction of flight component of > the aircrafts WEIGHT only. Ok, got it. But without wings (but still with the majority of the weight) will the glider still be propelled forwards? I guess not. Then what exactly is exercising a forward pulling force on the glider's fuselage? The fuselage has only drag. So something must be pulling it forward. Frans ________________________________ Message 10 ____________________________________ Time: 07:43:53 AM PST US From: Frans Veldman Subject: Re: Europa-List: Fuel tank sensor opening problem On 07/01/2013 04:29 PM, Fred Klein wrote: > If I recall correctly, the installation included an internal flange > plate which I now surmise should prevent fuel contacting the cut > edge...much appreciation if anyone can confirm this. I did not have the internal flange. I just riveted 5 anchor nuts to the tank and assumed this would be plenty for such a small surface. Well, it is not. I now have made an internal flange myself and hope that with the tank wall locked in between the sensor cap and internal flange that it won't leak anymore. Still the fuel can access the cut line but as this has already happened I'm not sure whether it makes sense to seal it now. Also, you need 5 holes through the tank wall to attach the whole thing, making it even harder to achieve a leak free fit. So, I will leave it as is and if it doesn't leak anymore I'm happy with it. Frans ________________________________ Message 11 ____________________________________ Time: 07:53:56 AM PST US From: GRAHAM SINGLETON Subject: Re: SV: Europa-List: Re: wing lift/drag pins Good point Svein=0AGraham=0A=0A=0A=0A=0A________________________________=0A From: Sidsel & Svein Johnsen =0ATo: europa-li st@matronics.com =0ASent: Monday, 1 July 2013, 15:21=0ASubject: SV: Europa- List: Re: wing lift/drag pins=0A =0A=0A=0AThis has been an interesting disc ussion, but it appears to me that it got off-track somewhere because "forwa rd" has two meanings (see the attached illustrations):=0A=C2-=0A(i)=C2- =C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2 -=C2-=C2-=C2- The LIFT does not have a =9Cforward=9D co mponent, under any circumstances, if FORWARD means the direction of the air craft=99s flight.=C2- Reason:=C2- LIFT is by definition always pe rpendicular to the direction of flight, as DRAG is always opposite to the d irection of flight (i.e. perpendicular to the LIFT).=0A=C2-=0A(ii)=C2- =C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2 -=C2- If, however, one refers to FORWARD as the direction of the aircra fts centerline, then LIFT has a =9Cforward=9D component as soon as the centerline points up at the nose relative to the direction of fligh t.=C2- The higher the nose points up, the greater this forward component is.=C2- At some point it may, as I read the discussion, become larger tha n the wing DRAG=99s component parallel to the centerline in the oppos ite direction, giving a net =9Cforward=9D force on the wing.=0A =C2-=0A(iii)=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2- =C2-=C2-=C2-=C2- The LIFT does not contribute, under any circumstan ces, to moving the aircraft forward through the air, as there is no lift co mponent parallel to the direction of flight.=C2- A glider is =9Cpro pelled=9D by the forward =93 in the direction of flight =93 component of the aircraft=99s WEIGHT only.=0A=C2-=0A=C2-=0ARe gards,=0ASvein=0ALN-SKJ ________________________________ Message 12 ____________________________________ Time: 08:05:44 AM PST US From: "Bob Harrison" Subject: RE: Europa-List: Fuel tank sensor opening problem Hi! Fred My oval hole cut in the tank top is protected by the plate internally and a silicone seal round the edges and I have had no problems of the swelling kind except I had a leak once from the pressure "head" by leaving a column of fuel right up the "cobra" filler over night . Better attention to the silicone casket and more intelligent filling seem to have prevented a repeat. No one advised me to ensure that the cut edge should be kept free from fuel contact. However early tanks had to have fuel stored and so be encouraged to " swell" prior to installation into the fuselage/cockpit module over a period of many weeks restrained by a strong frame surrounding it. So movement can be expected but by arranging suitable clamps and tight fixings I would have thought would restrain the swelling anyway. My Kit No is 337 but I know that a number of builders have suffered split tanks . I believe likely caused by letting the tank dry out after the impregnation by fuel . Keep fuel in and such swelling stays stable. (I think !) Regards to all in strife ! Bob Harrison. G-PTAG From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of Fred Klein Sent: 01 July 2013 15:29 Subject: Re: Europa-List: Fuel tank sensor opening problem On Jul 1, 2013, at 6:53 AM, richard wrote: Hi Frans I suggest you contact LAA and ask them for a copy of Mod 10602 which Ian Rickard had approved. This mod introduces a flange plate and seal assembly into the top of the tank. The important thing is that the flange seal is on the inside of the tank so no fuel contacts the out side or the cut edge. Hope this helps Regards Richard Europa xs Tri-gear 45hrs All, Though still just a the builder, I'm following this topic w/ keen interest and full sympathy for flyers who are experiencing fuel tank leaks and deformation. When I read about the introduction of tank mods such as #10602, am I correct in assuming that work of this nature is done AFTER slicing off the top of the CM, say, 1/2 inch down from the top flat surface?...or perhaps after slicing off one of the head rests, say 1/2 inch up from the top flat surface of the CM? Also...long ago I installed the Europa capacitance fuel gauge PRIOR to installing the tank in the CM. (At the time I was astounded to read the instructions' claim that it is possible to install the gauge AFTER installing the CM by working thru the access hole in the side of the head rest...I salute anyone who managed to do that!) If I recall correctly, the installation included an internal flange plate which I now surmise should prevent fuel contacting the cut edge...much appreciation if anyone can confirm this. Fred A-194 ________________________________ Message 13 ____________________________________ Time: 08:14:49 AM PST US From: Frans Veldman Subject: Re: Europa-List: Re: wing lift/drag pins On 07/01/2013 11:41 AM, Alan Carter wrote: > I don,t know, Just assume your wings fall off. What is your fuselage going to do? It will fall straight down after the short moment it looses its forward speed. Now keep the wings attached. Switch off the engine. Where is the fuselage going? It moves forward and keeps on moving forward. As the fuselage has drag, why is it moving forward against the drag? Who is pulling it? Is the connecting bar between the two rear sockets under compression or unter tension? Frans ________________________________ Message 14 ____________________________________ Time: 08:24:28 AM PST US From: "Sidsel & Svein Johnsen" Subject: SV: SV: Europa-List: Re: wing lift/drag pins Frans, Our postings are crossing a little, but I think the below covers also your last one: > > How does an autogyro (autocopter?) work? What is causing the blades to > move forward? > See http://en.wikipedia.org/wiki/Autogiro > > A glider is > > "propelled" by the forward - in the direction of flight - component of > > the aircraft's WEIGHT only. > > Ok, got it. But without wings (but still with the majority of the > weight) will the glider still be propelled forwards? I guess not. Again: What is meant by "forward"? Without wings, the glider will still be propelled forwards, and still by gravitational force. Unfortunately for the pilot, however, "forward" now means more or less vertical towards the ground .......... > Then what exactly is exercising a forward pulling force on the glider's > fuselage? The fuselage has only drag. So something must be pulling it > forward. > I may be stating the obvious, but a glider is always going down, or rather gliding down - down relative to the air mass through which it moves. If the air mass is moving upwards (thermals) faster than the glider moves downwards through that air mass, the glider climbs relative to the ground even though it goes down relative to the air mass. All the time, it is the gravity that causes it to move, and movement through the air creates lift (if the wings are still on), so that the glider does not fall like a stone through the surrounding air mass. When the total drag on the glider equals the gravity's component in the direction of flight, the glider does not accelerate any more, it has reached constant speed. Same thing with an airplane with engine, if the engine quits. As long as the engine works, though, and we fly level, the engine gives enough pull to equal the total drag, so that we don't need any assistance by the gravity to create speed. At level flight, the lift and the down force by the stabilizer are vertical. Gravity is always vertical. I.e. no fore-or-aft force component from any of these three forces. Only drag, which equals propeller pull at constant speed. Regards, Svein ________________________________ Message 15 ____________________________________ Time: 08:37:19 AM PST US From: "Sidsel & Svein Johnsen" Subject: SV: Europa-List: Re: wing lift/drag pins - ADDITION In my most recent posting, I wrote: "...a glider is always going down, or rather gliding down - down relative to the air mass through which it moves". The exception is of course if using the mass inertia of the glider for a short-duration movement up through the air. This is when the in-the-direction-of-the-centerline forward force on the wing may exceed the opposite-direction wing drag component, and the cross tie bar comes under tension, not compression. Regards, Svein ________________________________ Message 16 ____________________________________ Time: 09:23:41 AM PST US From: "Raimo Toivio" Subject: Re: SV: SV: Europa-List: Re: wing lift/drag pins > > A glider is > > "propelled" by the forward - in the direction > > of flight - component of > > the aircraft's WEIGHT only. And thats why they (gliders) obviously fill also sometimes their watertanks - to get more load, to feed gravity and to get speed? Cheers, Raimo -----Alkuperinen viesti----- From: Sidsel & Svein Johnsen Sent: Monday, July 01, 2013 6:24 PM Subject: SV: SV: Europa-List: Re: wing lift/drag pins Johnsen" Frans, Our postings are crossing a little, but I think the below covers also your last one: > > How does an autogyro (autocopter?) work? What is > causing the blades to > move forward? > See http://en.wikipedia.org/wiki/Autogiro > > A glider is > > "propelled" by the forward - in the direction > > of flight - component of > > the aircraft's WEIGHT only. > > Ok, got it. But without wings (but still with > the majority of the > weight) will the glider still be propelled > forwards? I guess not. Again: What is meant by "forward"? Without wings, the glider will still be propelled forwards, and still by gravitational force. Unfortunately for the pilot, however, "forward" now means more or less vertical towards the ground .......... > Then what exactly is exercising a forward > pulling force on the glider's > fuselage? The fuselage has only drag. So > something must be pulling it > forward. > I may be stating the obvious, but a glider is always going down, or rather gliding down - down relative to the air mass through which it moves. If the air mass is moving upwards (thermals) faster than the glider moves downwards through that air mass, the glider climbs relative to the ground even though it goes down relative to the air mass. All the time, it is the gravity that causes it to move, and movement through the air creates lift (if the wings are still on), so that the glider does not fall like a stone through the surrounding air mass. When the total drag on the glider equals the gravity's component in the direction of flight, the glider does not accelerate any more, it has reached constant speed. Same thing with an airplane with engine, if the engine quits. As long as the engine works, though, and we fly level, the engine gives enough pull to equal the total drag, so that we don't need any assistance by the gravity to create speed. At level flight, the lift and the down force by the stabilizer are vertical. Gravity is always vertical. I.e. no fore-or-aft force component from any of these three forces. Only drag, which equals propeller pull at constant speed. Regards, Svein browse Un/Subscription, FAQ, http://www.matronics.com/Navigator?Europa-List Forums! List Admin. ________________________________ Message 17 ____________________________________ Time: 09:49:29 AM PST US From: Frans Veldman Subject: Re: SV: SV: Europa-List: Re: wing lift/drag pins On 07/01/2013 05:24 PM, Sidsel & Svein Johnsen wrote: >> Then what exactly is exercising a forward pulling force on the glider's >> fuselage? The fuselage has only drag. So something must be pulling it >> forward. >> > I may be stating the obvious, but a glider is always going down, I guess it is also obvious that it is going down much quicker without the wings, and with less forward velocity. So the question remains, if the fuselage without wings has a lower forward speed than a fuselage with wings, can't we just say that this means that the wings are pulling the fuselage forwards? No way that the fuselage itself will maintain a forward speed of 100 knots or so, the drag is quite substantial, so something is pulling it forward against the drag. And in the few examples where the wings detached during flight, it is indeed observed that the wings fold forwards. The wings MUST BE pulling the fuselage forwards, because the fuselage would never do this by itself. I can't see how one could argue against that. > All the time, it is the gravity that > causes it to move, Yes, gravity is providing the energy that makes it happen. No doubt about that. But this is something else than saying that the wings play no role in it. Sure the wings play a role in it: they counter partly the gravity and redirect the energy to propel the aircraft forward. > Same thing with an airplane with engine, if the engine quits. As long as > the engine works, though, and we fly level, the engine gives enough pull to > equal the total drag, The engine provides extra energy, so we don't loose altitude while "going down". Frans ________________________________ Message 18 ____________________________________ Time: 10:00:14 AM PST US From: "Sidsel & Svein Johnsen" Subject: SV: SV: SV: Europa-List: Re: wing lift/drag pins > > > A glider is > > > "propelled" by the forward - in the direction of flight - component > > > of the aircraft's WEIGHT only. > > And thats why they (gliders) obviously fill also sometimes their watertanks - > to get more load, to feed gravity and to get speed? > > Cheers, Raimo > Yes, Raimo, that is one of the main reasons for the water ballast. At the same glide ratio, you get higher speed with than without ballast. Just look at the bottom illustration in my first e-mail: Higher weight gives larger gravity component in direction of flight at the same angle of flight vs. horizontal. Larger pulling force gives higher speed - the glider accelerates until the higher pulling force equals the increasing drag. Higher speed gives higher lift (square of speed increase) to carry the higher weight, so that you can maintain the glide ratio (direction of flight vs. horizontal). Regards, Svein ________________________________ Message 19 ____________________________________ Time: 10:05:43 AM PST US Subject: Europa-List: Water ballast From: andrew cullum Yes Raimo, You are correct,the water ballast actually increases the gliders "inertia", and as a consequence,the glide angle is better at higher speeds. The trade off of course is poorer climb Performance in lift,but on good days, The advantage of carrying water out-weighs this. However pilots may find they have to Dump some or all of their water to climb And get home if soaring conditions get Worse. Best Regards Andy Cullum. Sent from my iPhone ________________________________ Message 20 ____________________________________ Time: 10:36:58 AM PST US Subject: Europa-List: Re: wing lift/drag pins From: "Alan Carter" Hello Frans. Who is pulling it. Gravity It will move is an arc towards the ground. A wing is similar to a sail on a sailing boat. You can not sail directly into wind you can get to about 30 degrees of it. Sorry Frans but at the moment i am still puzzled. At the moment i am thinking this bar has three purposes, 1. to prevent the drag pulling the wing back, which is most of the time. 2. two provide the rigidity to the structure so keeping the front pin locked into its mounting. 3. to stop the wing coming "forwards" in abnormal wing loadings, Possible very high A/A, near the stall, or gusts, or abnormal flight attitudes. This puts this bar in compression , tension and neutral loads But i am willing to change my mind,as i have used up ask a friend, may be its time to ask the audience, Regards . Alan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=403725#403725 ________________________________ Message 21 ____________________________________ Time: 10:49:44 AM PST US From: "Sidsel & Svein Johnsen" Subject: SV: SV: SV: Europa-List: Re: wing lift/drag pins Frans, The forces are as illustrated in my first posting. If you throttle back the engine, all properly designed and built aircraft automatically pitches down to gain speed. The pitch-down is of course the result of the stabilizer's design and angle of incidence vs. the wings' . Why gain speed: To give required lift. To get enough speed to give the required lift, the pulling force must be kept up. Lost propeller thrust must be compensated by something. As lift CANNOT give force in the direction of flight (remember, BY DEFINTION it is perpendicular to the direction of flight, thus it has no forwards nor backwards component flight-direction-wise). What is this "something" force that compensates for engine power? Look at the bottom illustration in my first posting: To create a forward force (forward meaning in the direction of flight) to maintain speed to maintain lift, the only possible force available is the gravity's flight-direction component. The steeper the pitch-down, the larger this force becomes, and the faster down you fly. This creates more lift (perpendicular to the flight direction), of course, but the vertical component of the lift remains the same - equal to the weight of the aircraft plus the vertical component of the downward stab. force. The gravity component acts on every atom in the structure's molecules, but we commonly consider them all grouped together at what we refer to as the center of gravity (CG), and uses this as point as the one common point where the total pulling force acts. Neither the fuselage nor the wings pull the aircraft forward, good ol' gravity does it all by itself! Do this, Frans: Shake off all your conceptions. Look ONLY at my illustrations. The global airplane forces are actually this simple. Alan, Right on! Regards, Svein ________________________________ Message 22 ____________________________________ Time: 03:25:51 PM PST US Subject: Europa-List: Re: wing lift/drag pins From: "rparigoris" Hi Group I have been following this thread with interest. I have been picking the brain of an ex Grumman X-29 FSW lead wind tunnel engineer as far as our Europa wings trying to move fore or aft, and all I know at the moment (pun intended) is how much I don't know. He asked a few pointed questions about the Europa, can you help me out with answering them?: **** What percent chord is the main spar at? **** What wing section does the aircraft use? **** What is the relationship (distance) between the main spar and the aft fitting? Once I provide him with these details, he will come back with his take on the subject. I will post his answer along with other comments he has made already. Thx. Ron Parigoris BTW Frans, I have always thought of a Gyrocopter as an aeroplane with a big pancake of a wing above you. When you spin up the blades, they don't allow much in the way of airflow through the spinning blades. Think of a big disk you put at a positive angle of attack above you. Kinda neat concept, not very efficient, takes a lot of pushing energy to keep your rotors spinning up to make it act like a solid disc. Here is an E-Mail I sent: Hey Guyz A Europa member was trying to explain to another member why at high angles of attack the wings want to sweep forward. There are other members that tried to explain in words, one just said well, it's the same reason why a Gyrocopter rotor spins in the direction that it does which with little thought seems to be spinning in the wrong direction. Attached is a diagram that is a pretty good visualization. Ron P. Here's his reply: No its not (a good visualization) You have to apply real numbers to those phoney scalers on that figure. At high AOA the drag is significantly higher than shown, but lift not so much so. This would pull the L/D resultant much father aft. Those two plots are implying that the L/D of a wing is the same at cruise and at high AOA which we all KNOW is not true! (the reason you never fly a high performance sailplane near Cl Max!) There is one good reason for putting fwd sweep in a wing planform. It allows less use of washout to keep the tip from stalling. If the wing is swept TOO far fwd, the twist actually reverses! The root must be a lower AOA than the tip, sometimes by a lot. The biggest DISADVATAGE to FSW planform wings is structural divergence. Load the wing up, and without a sufficiently strong wing box structure, the wing tip will twist to a higher AOA producing more twist repeat as necessary until failure (catastrophic I might add!) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=403743#403743 ________________________________ Message 23 ____________________________________ Time: 03:54:01 PM PST US Subject: Europa-List: Re: wing lift/drag pins From: "Alan Carter" Hi Ron. Glad you are interested. If you read the topic from the beginning it imply,s that the sole purpose of this bar was to prevent the wings from being pulled forward all the time during flight. I,m getting to old for all of this, but as an instructor many years ago i use to draw all the forces on the blackboard,and i never drew a wing vector added to the thrust vector, So got me thinking why, and i slowly began to come round to thinking there may be some forward component but not occurring in normal flight. The tie bar came in with the weight increase mod, with the bigger spar pins, the swivelling rear fuselage pin socket and the tie strap on the spar. Then when we had the in flight break up the tie bar became a mandatory mod for all Europa's with the extra long rear wing pins with big washer and nut inside the wing root. I think its purpose is as i have stated, and re enforces the whole structure around the wing and mounting points, and i believe this weak spot was part of the break up, May not have been the initial cause, that may well have been something to do with the Stabalator. I may be wrong, I have never built an aeroplane, and im just a simple country boy,with a pair of eye,s, but do have the right to post my opinion, I am polite, never make fun of, or discourage any member from posting, and always willing to listen to another point of view, I am just interested in this particulate topic, and will look forward to your posting, sorry i can,t give you the information you requested, I just fly the plane. Regards. Alan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=403746#403746 ________________________________ Message 24 ____________________________________ Time: 11:01:31 PM PST US From: Matt Dralle Subject: Europa-List: Official Europa-List FAQ (Frequently Asked Questions) Dear Listers, Please read over the Europa-List Frequently Asked Questions (FAQ) below. The complete Europa-List FAQ including the Usage Guidelines can be found at the following URL: http://www.matronics.com/FAQs/Europa-List.FAQ.html Thank you, Matt Dralle Matronics Email List Administrator [ Note: This FAQ was designed to be displayed with a fixed width font such as Courier. Proportional fonts will cause display formatting errors. ] This FAQ can also be viewed in HTML online at the following address: http://www.matronics.com/FAQ/Europa-List.htm ************************************************************ ******* LIST POLICIES AND FREQUENTLY ASKED QUESTIONS ******* ************************************************************ PLEASE READ. This document contains Europa-List policies and information for new and old subscribers. Understanding the Europa-List policies will minimize problems for the Administrator, and will help keep the Europa-List running smoothly for all of us. ****************************************** *** Quick Start Guide to List Features *** ****************************************** There are many features available on the Matronics Email Lists and each one is described in detailed below. However, using the List Navigator you can quickly access the complete set of features available for this List. The List Navigator can be found at the following URL: http://www.matronics.com/Navigator?Europa-List **************************************** *** How to Subscribe and Unsubscribe *** **************************************** Simply go to the Web Page shown below and enter your email address and select the List(s) that you wish to subscribe or unsubscribed from. You may also use the handy "Find" function to determine the exact syntax of your email address as it is subscribed to the List. Please see the complete instructions at the top of the Web Page for more information. The Subscribe/Unsubscribe web page is: http://www.matronics.com/subscribe Note that you will receive TWO conformation emails regarding your subsciption process. The first verifies that your subscription/unsubsciption request was received, and the second confirms that the process has been completed. You should receive the first email within a few minutes of your request. The second conformation will arrive in less than 24 hours. You cannot post until you receive the second conformation email message. ***************************** *** How to Post a Message *** ***************************** Send an email message to: europa-list@matronics.com Your message will be redistributed to everyone currently subscribed to the List. ***************************************************** *** SPAM Fighter - You Must be Subscribed to Post *** ***************************************************** When a new post is received by the system, the From: line of the message is checked and compared against the current subscription list. If the email address is found, the message is passed on to the List Processor. If the email address isn't found in the current list of subscribers, it is dumped. This serves to very effectively thwart 99% of the SPAM that gets posted to the Lists. Remember, however, that the syntax of your email address is very important with regard to the configuration of your email application such as Outlook or Eudora. For example, the following two email addresses may be functionally equivalent, but only one would pass the Matronics Email SPAM test depending on which was syntax was subscribed to the given List: smith@machine.domain.com smith@domain.com Either email address syntax is alright, just be sure that you configure your email application to match *exactly* the address you've subscibed to the List. ************************************** *** Enclosure Support on the Lists *** ************************************** Limited posting of enclosures such as pictures, documents, and spreadsheets is supported on the Lists. There are a number of restrictions, and these are detailed below. Please abide by the rules put forth regarding the content of enclosures. These are some of the features and limits of enclosures on the Matronics Lists: 1) Enclosures will only be posted to the Real Time version of the Lists. 2) Enclosures will NOT be included in the Daily Digest version of the Lists. 3) Enclosures WILL BE forwarded on to the BBS Forum Web site. 4) Enclosures will NOT be appended to the Archives. 5) Enclosures will NOT be available in the List Browse feature. 6) Only the following file types and extensions will be allowed: bmp doc dwg dxf gif jpg pdf png txt xls All other enclosures types will be rejected and email returned to sender. The enclosure types listed above are relatively safe from a virus standpoint and don't pose a particularly large security risk. 7) !! All incoming enclosures will be scanned for viruses prior to posting to the List. This is done in real time and will not slow down the process of posting the message !! Here are some rules for posting enclosures. Failure to abide by these rules could result in the removal of a subscriber's email address from the Lists. 1) Pay attention to what you are posting!! Make sure that the files you are enclosing aren't HUGE (greater that 1MB). Remember that there are still people checking they're email via dial up modem. If you post 30MB worth of pictures, you are placing an unnecessary burden on these folks and the rest of us, for that matter. 2) SCALE YOUR PICTURES DOWN!!! I don't want to see huge 3000 x 2000 pictures getting posted that are 3 or 4MB each. This is just unacceptable. Use a program such as Photoshop to scale the picture down to something on the order of 800 x 600 and try to keep the file size to less-than 200KB, preferably much less. Microsoft has a really awesome utility available for free that allows you to Right-Click on a picture in Explorer and automatically scale it down and resave it. This is a great utility - get it, use it! http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx Look for the link "Image Resizer" 3) !! This would seem to go without saying, but I'll say it anyway. Do not post anything that would be considered offensive by your grandmother. And you know what I'm saying; I don't want to see anything even questionable. !! 4) REMEMBER THIS: If you post a 1MB enclosure to a List with 1000 members subscribed, your 1MB enclosure must be resent 1000 times amounting to 1MB X 1000 = 1 Gigabyte of network traffic!! BE CAREFUL and BE COURTEOUS! Also see the section below on the Matronics Photo and File Share where you can have your files and photos posted on the Matronics web server for long time viewing and availability. ******************* *** Digest Mode *** ******************* Each day, starting at 12 midnight PST US, a new 'digest' will be started. This digest will contain the same information that is currently appended to the archive file. It has all of the headers except for the "From:" and "Subject:" lines removed, and includes a message separator consisting of a line of underscores. Each day at 23:55 PST US, the day's messages as described above will be combined and sent as a single message to everyone on the digest email list. To subscribe to the digest list, use the same subscription web form described above, and just select the Digest version of the List. http://www.matronics.com/subscribe Note that you *can* be subscribed to both the realtime and digest versions of the List at the same time. This is perfectly acceptable. Now some caveats: * Messages sent to "europa-list-digest" will be forwarded to the standard email list. In other words, you cannot post messages only to the digest List. * If you are subscribed to both the regular List and the digest List, you will receive the realtime postings as well as the digest at the end of the day. * If you reply to the digest email, your message will be forwarded to the normal list associated with the digest. Important Note: Please change the subject line to reflect the topic of your response! Also, please *do not include all or most of the digest in your reply*. **************************** *** List Digest Browser *** **************************** An archive of all the List Digests can be found online in either plain text or HTML format. These archives contain the exact Digest that was posted to the Digest email list on the given day. The Digest Archives can be found at the following location: http://www.matronics.com/digest ***************************************** *** The "DO NOT ARCHIVE" Message Flag *** ***************************************** At times, your message may concern something that is revelent only to a very small number of persons or to a limited area, and you may not wish to archive it. In such a case, simply put the following phrase anywhere in the message: do not archive Your message will not be appended to the archive, but will be sent to List email distribution as normal. ********************************************** ***** READ THIS - Automatic Unsubscribes ***** ********************************************** Note that if your email address begins to cause problems such as bounced email, mailbox is filled, or any other errors, your address will be promptly removed from the List. If you discover that you are no longer receiving messages from the Europa-List, go to the following Web page, and look for your email address and a possible reason for your removal. The Matronics Email List uses utility called the "Email Weasel" that automatically looks though the day's bounced email for addresses that caused problems due to common things like "user is unknown", "mailbox full", etc. If the Email Weasel removes your email address from the Lists you will find record of it at the following URL: http://www.matronics.com/unsubscribed If the problem listed on the web site above has been resolved, please feel free to resubscribe to the Lists of your choice. ******************************* *** List Member Information *** ******************************* If you have not done so already, please email me your phone numbers and paper mail address in the following format: smith@somehost.com Joe Smith 123 Airport Lane Tower, CA 91234-1234 098-765-1234 w 123-456-7890 h Please forward this information to the following email address: requests@matronics.com I have a file of such things, that I typically use to contact you when there are problems with your email address. The information will NOT be used for any other commercial purpose. **************************************** *** Realtime Web Email List Browsing *** **************************************** Recent messages posted to the Europa-List are also made available on the Web for realtime browsing. Seven days worth of back postings are available with this feature. The messages can be sorted by Subject, Author, Date, or Message Thread. The Realtime List Browser indexes are updated twice per hour at xx:15 and xx:45. You can also reply to a message or start a new message directly from the List Browser Interface (coming soon). You do not have to be subscribed to the given list to use the List Browser Interface in view-mode. http://www.matronics.com/browselist/europa-list ******************************************* *** Web Forums Bulletin Board Interface *** ******************************************* A phpBB BBS web Forums front end is available for all Europa-List content. content. The Forums contain all of the same content available via the email distribution and found on the various archive viewing formats such as the List Browse, etc. Any posts on the web Forums will be cross posted to the respective email List, and posts to the Email List will be cross posted to the web Forums. You may view all List content on the Forums without any special login. If you wish to post a message via the Web Forum interface, however, you will need to Register. This is a simple process that takes only a few minutes. A link to the Registration page can be found at the top of the main web Forums page. Note that registering on the Forum web site also enables you to send email posts to the Lists as well. You will also need to Subscribe to the respective Email List as described above to receive the Email Distribution of the List, however. The Matroincs Email List Web BBS Forums can be found at the following URL: http://forums.matronics.com ********************************* *** Matronics Email List Wiki *** ********************************* In an attempt to make it easy to store and find structured and often accessed information, Matronics has installed a Wiki at: http://wiki.matronics.com The Wiki allows individuals to create web pages to contain useful information for other users of the mailing lists and web site. Unlike an ordinary web page where the content needs to be submitted to Matronics for inclusion, the Wiki permits the users to construct their own pages and have them visible immediately. While constructing pages for the Wiki is not difficult, some may not be comfortable building pages. In that case, simply prepare the text and any images and email it to: wiki-support@matronics.com One of the volunteers on that list will take your submission and construct a Wiki page for you. Often someone produces a particularly useful posting in email one one of the Lists that would be of general interest. In that case Matronics may take that post and convert it into a Wiki page. ********************* *** List Archives *** ********************* A file containing of all of the previous postings to the Europa-List is available on line. The archive file information is available via the Web and FTP in a number of forms. Each are briefly described below: * Europa-List.FAQ - Latest version of the Europa-List Frequently Asked Question page (this document). * Europa-Archive.digest.complete - Complete file with most of the email header info removed and page breaks inserted between messages. * Europa-Archive.digest.vol-?? - Same as the file above, but broken up into small sections that can more easily handled. * Europa-Archive.digest.complete.zip - Same as the Europa-Archive.digest.complete file above, but in PKZIP format. Use "binary" data transfer methods. * Europa-Archive.digest.complete.Z - Same as the Europa-Archive.digest.complete file above, but in UNIX compress format. Use "binary" data transfer methods. Download Via FTP ---------------- The archive file is available via anonymous FTP from ftp.matronics.com in the "/pub/Archives" directory. It is updated daily and can be found in a number of formats as described above. (All filenames are case sensitive.) ftp://ftp.matronics.com/pub/Archives Download Via Web ---------------- The archives are also available via a web listing. These can be found toward the bottom of the following web page: http://www.matronics.com/archives ****************************************** *** Complete List Web Archive Browsing *** ****************************************** All messages posted to the Europa-List are also available using the Email List Archive Browsing feature. With this utility, all messages in the List are indexed, and individual sub-archives can be browsed. http://www.matronics.com/archive/archive-index.cgi?Europa ***************************************** **** High-Speed Archive Search Engine *** ***************************************** You can use the custom, high-performance Matronics Email List Search Engine to quickly locate and browse any messages that have been posted to the List. The Engine allows the user to easily search any of the currently available List archives. http://www.matronics.com/search **************************** *** File and Photo Share *** **************************** With the Matronics Email List File and Photo Share you can share pictures and other data with members of the List without having to forward a copy of it to everyone. To share your Files and Photos, simply email them to: pictures@matronics.com !! ==> Please including the following information with each submission: 1) Email Lists that they are related to. 2) Your Full Name. 3) Your Email Address. 4) One line Subject description. 5) Multi-line, multi-paragraph description of topic. 6-x) One-line Description of each photo or file Prior to public availability of the files and photos, each will be scanned for viruses. Please also note that the process of making the files and photos available on the web site is a pseudo-manual process, and I try to process them every few days. Following the availability of the new Photoshare, an email message will be sent to the Email Lists enumerated in 1) above indicating that the new Share is available and what the direct URL to it is. For a current list of available Photoshares, have a look at the Main Index Page: http://www.matronics.com/photoshare ************************** *** List Archive CDROM *** ************************** A complete Matronics Email List Archive CD is available that contains all of the archives since the beginning of each of the Lists. The archives for all of the Lists are included on the CD along with a freeware search engine written by a list member. The CD is burned the day you order it and will contain archive received up to the last minute. They make great gifts! http://www.matronics.com/ArchiveCDROM ********************************** *** List Support Contributions *** ********************************** The Matronics Lists are run *completely* through the support of it members. You won't find any PopUpAds, flashing Banner ads, or any other form of annoying commercialism on either the Email Messages or the List web pages associated with the Matronics Email Lists. Every year during November I run a low-key, low-pressure "Fund Raiser" where, throughout the month, I ask List members to make a Contribution in any amount with which they are comfortable. I will often offer free gifts with certain contribution levels during the Fund Raiser to increase the participation. The gifts are usually donated by companies that are themselves List members. Your Contributions go directly to supporting the operation of the Lists including the high-speed, business-class Internet connection, server system hardware and software upgrades, and to partially offset the many many hours I spend running, maintaining, upgrading, and developing the variety of services found here. Generally Contributions range from $20 to $100 and are completely voluntary and non-compulsory. I ask only that if person enjoys the Lists and obtains value from them, that they make a Contribution of equal magnitude. Contributions are accepted throughout the year, and if you've just subscribed, feel free to make a Contribution when you've settled in. The website for making SSL Secure Contributions is listed below. There are a variety of payment methods including Visa and MasterCard, PayPal, and sending a personal check. If you enjoy and value the List, won't you make a Contribution today to support its continued operation? http://www.matronics.com/contributions Thank you! Matt Dralle Email List Administrator ****************************************************************************** Europa-List Usage Guidelines ****************************************************************************** The following details the official Usage Guidelines for the Europa-List. You are encouraged to read it carefully, and to abide by the rules therein. Failure to use the Europa-List in the manner described below may result in the removal of the subscribers from the List. Europa-List Policy Statement The purpose of the Europa-List is to provide a forum of discussion for things related to this particular discussion group. The List's goals are to serve as an information resource to its members; to deliver high-quality content; to provide moral support; to foster camaraderie among its members; and to support safe operation. Reaching these goals requires the participation and cooperation of each and every member of the List. To this end, the following guidelines have been established: - Please keep all posts related to the List at some level. Do not submit posts concerning computer viruses, urban legends, random humor, long lost buddies' phone numbers, etc. etc. - THINK carefully before you write. Ask yourself if your post will be relevant to everyone. If you have to wonder about that, DON'T send it. - Remember that your post will be included for posterity in an archive that is growing in size at an extraordinary rate. Try to be concise and terse in your posts. Avoid overly wordy and lengthy posts and responses. - Keep your signature brief. Please include your name, email address, aircraft type/tail number, and geographic location. A short line about where you are in the building process is also nice. Avoid bulky signatures with character graphics; they consume unnecessary space in the archive. - DON'T post requests to the List for information when that info is easily obtainable from other widely available sources. Consult the web page or FAQ first. - If you want to respond to a post, DO keep the "Subject:" line of your response the same as that of the original post. This makes it easy to find threads in the archive. - When responding, NEVER quote the *entire* original post in your response. DO use lines from the original post to help "tune in" the reader to the topic at hand, but be selective. The impact that quoting the entire original post has on the size of the archive can not be overstated! - When the poster asks you to respond to him/her personally, DO NOT then go ahead and reply to the List. Be aware that clicking the "reply" button on your mail package does not necessarily send your response to the original poster. You might have to actively address your response with the original poster's email address. - DO NOT use the List to respond to a post unless you have something to add that is relevant and has a broad appeal. "Way to go!", "I agree", and "Congratulations" are all responses that are better sent to the original poster directly, rather than to the List at large. - When responding to others' posts, avoid the feeling that you need to comment on every last point in their posts, unless you can truly contribute something valuable. - Feel free to disagree with other viewpoints, BUT keep your tone polite and respectful. Don't make snide comments, personally attack other listers, or take the moral high ground on an obviously controversial issue. This will only cause a pointless debate that will hurt feelings, waste bandwidth and resolve nothing. - Occasional posts by vendors or individuals who are regularly subscribed to a given List are considered acceptable. Posts by List members promoting their respective products or items for sale should be of a friendly, informal nature, and should not resemble a typical SPAM message. The List isn't about commercialism, but is about sharing information and knowledge. This applies to everyone, including those who provide products to the entire community. Informal presentation and moderation should be the operatives with respect to advertising on the Lists. ------- [This is an automated posting.] do not archive ________________________________ Message 25 ____________________________________ Time: 11:06:01 PM PST US From: Matt Dralle Subject: Europa-List: Official Europa-List Usage Guidelines Dear Listers, Please read over the Europa-List Usage Guidelines below. The complete Europa-List FAQ including these Usage Guidelines can be found at the following URL: http://www.matronics.com/FAQs/Europa-List.FAQ.html Thank you, Matt Dralle Matronics Email List Administrator ****************************************************************************** Europa-List Usage Guidelines ****************************************************************************** The following details the official Usage Guidelines for the Europa-List. You are encouraged to read it carefully, and to abide by the rules therein. Failure to use the Europa-List in the manner described below may result in the removal of the subscribers from the List. Europa-List Policy Statement The purpose of the Europa-List is to provide a forum of discussion for things related to this particular discussion group. The List's goals are to serve as an information resource to its members; to deliver high-quality content; to provide moral support; to foster camaraderie among its members; and to support safe operation. Reaching these goals requires the participation and cooperation of each and every member of the List. To this end, the following guidelines have been established: - Please keep all posts related to the List at some level. Do not submit posts concerning computer viruses, urban legends, random humor, long lost buddies' phone numbers, etc. etc. - THINK carefully before you write. Ask yourself if your post will be relevant to everyone. 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The List isn't about commercialism, but is about sharing information and knowledge. This applies to everyone, including those who provide products to the entire community. Informal presentation and moderation should be the operatives with respect to advertising on the Lists. ------- [This is an automated posting.] do not archive ________________________________ Message 26 ____________________________________ Time: 11:23:55 PM PST US From: "Sidsel & Svein Johnsen" Subject: SV: Europa-List: Re: wing lift/drag pins Ron, >From your message: > Attached is a diagram that is a pretty good visualization. > Ron P. > > Here's his reply: > No it=C3=A2=82=AC=84=A2s not=C3=A2=82=AC=C2 (a good visualization) > > You have to apply real numbers to those phoney scalers on that figure. > > At high AOA the drag is significantly higher than shown, but lift not so much > so. This would pull the L/D resultant much father aft. > > Those two plots are implying that the L/D of a wing is the same at cruise and > at high AOA which we all KNOW is not true! (the reason you never fly a high > performance sailplane near Cl Max!) > I assume it was my illustration that you forwarded to your friend. If so, I agree with his statement about L/D - the vectors are not to scale at all, and were not intended to be. I realize, however, that I should have emphasized this and also increased the length of the wing drag vector at the high AOA illustration, but this has no bearing on the lift component issue. My message =93 and illustration - had two purposes, which perhaps your friend was not aware of: - To show that lift has no component in the direction of flight, regardless of the angle of attack, while lift may have a =9Cforward=9D component, if "forward" means the direction the nose is pointing. - To show that a glider is pulled forward (in the direction of gliding flight) by gravity, not by any lift component. I have not made any calculation of the magnitude of the =9Cforward=9D lift component vs. drag on Europa or any other airplane, which is why I just referred to arguments and observations presented by others: "At some point it may, as I read the discussion, become larger than the wing DRAG=99s component parallel to the centerline in the opposite direction, giving a net =9Cforward=9D force on the wing." The magnitude of such a =9Cforward=9D component is only dependent on the magnitude of the lift and the angle between the centerline and the direction of flight. The magnitude of drag does not come in here. The resultant force on the wing, however, and whether it acts =9Cforward=9D or =9Cbackward=9D, depends also on the drag magnitude. I apologize if I have caused any confusion about wing L/D vs. AOA (I don=99t really think I have, though!) Regards, Svein ------------------------------------------------------------------------------------- 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.