[Aus-soaring] Mandl extractor - Is it snake oil or is there something to it?
It's referring to this: http://www.dg-flugzeugbau.de/mandl-absaugung-e.html Any comment from aeronautical engineering types? Have DG's results been independently verified? ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it?
Not sure about independent, but Jonker does the same thing for their JS1's, and I've heard of experimental ASW20 mods to add one. http://www.jonkersailplanes.co.za/index.php?pageid=36 -Matthew On Tue, Jun 5, 2012 at 3:48 PM, Texler, Michael michael.tex...@health.wa.gov.au wrote: It's referring to this: http://www.dg-flugzeugbau.de/mandl-absaugung-e.html Any comment from aeronautical engineering types? Have DG's results been independently verified? ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it?
An air extractor system definitely makes the cockpit quieter and the ventilation system work better - that along improves pilot comfort and performance. SDF On 05/06/2012, at 16:18, Texler, Michael michael.tex...@health.wa.gov.au wrote: It's referring to this: http://www.dg-flugzeugbau.de/mandl-absaugung-e.html Any comment from aeronautical engineering types? Have DG's results been independently verified? ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it?
At 04:40 PM 5/06/2012, you wrote: Not sure about independent, but Jonker does the same thing for their JS1's, and I've heard of experimental ASW20 mods to add one. http://www.jonkersailplanes.co.za/index.php?pageid=36 -Matthew No the JS-1 vent is not the same as the Mandl extractor although both aim to suck exit air out through a low pressure point. The Mandl device is on the bottom of the fuselage and looks to be in around the trailing edge of the wing location in the fore and aft sense. The JS-1 vent is on top of the fuselage not far aft of the canopy and it has a little wing in it to get the air to flow along the surface better. The JS-1 location is likely a lower pressure area (top of wing and fat part of fuselage) than the lower fuselage lined up with the wing TE where the pressure is about back to static pressure. Also the Mandl extractor doesn't seem to try to flow the exit air parallel to the airstream. Some tests with dye or tufts would be interesting as well as static pressure measurements. Don't forget also if you manage to put the vent in a low pressure area and close the inlet, cockpit pressure will be a fair bit lower than outside - maybe up to 100 feet or so altitude equivalent with consequent effects on the pressure altitude measured by your logger. This is by no means a new idea to have an exit vent. Wil Schumann used the back of the gear doors as an extractor on his H301b Libelle. I had an exit vent on my Mini Nimbus in 1978. Gliders are coming out with better cockpit ventilation nowadays. It took long enpough. failure to provide adequate ventilation in the cockpit is like failing to provide proper cooling for the engine in a powered aircraft. Mike Borgelt Instruments - design manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784: int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it?
I was surprised to see the JS-1 vent didn't have a nice funnel to guide the cockpit airflow in to it. Just cut off square inside. Don't know how much difference this mkes. Mike Borgelt Instruments - design manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784: int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it?
Air into the cockpit must equal air out. If you are ramming air into the cockpit and do not have a suitable exit, where does it go? Predominantly out around the edges of the canopy and worse still along through the wing roots and out the air brake box. In 'very bad' examples it is the equivalent of having the airbrakes unlocked (but not open) which is enough of a performance drop to be noticeable to the pilot. The solution is to provide a 'nice' way of exiting the air without disturbing the surface flow too much. The JS1 idea is very neat, but complex. The DG way is relatively crude. In older types , an air extractor is a way of getting your 34:1 Std Libelle (or similar) a bit back towards the quoted 38:1. Personally, I plan to have an extractor on the Bergfalke behind the (fixed) main wheel. I can't make the louvers like Jonkers, and detest the crudity of the DG design, so I am playing with the concept of making a true reverse NACA duct (which is NOT the same as having a NACA scoop facing backwards) behind the fixed main wheel. The reason why? It is impossible to completely seal the nose release in the Bergfalke. As I have air coming in continuously, I might as well have somewhere to dump it and the air behind the main wheel is already pretty disturbed (which may actually defeat the reverse NACA concept - the original NACA inlet duct design was for laminar flow). From: aus-soaring-boun...@lists.internode.on.net [mailto:aus-soaring-boun...@lists.internode.on.net] On Behalf Of Mike Borgelt Sent: Tuesday, 5 June 2012 5:44 PM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it? At 04:40 PM 5/06/2012, you wrote: Not sure about independent, but Jonker does the same thing for their JS1's, and I've heard of experimental ASW20 mods to add one. http://www.jonkersailplanes.co.za/index.php?pageid=36 -Matthew No the JS-1 vent is not the same as the Mandl extractor although both aim to suck exit air out through a low pressure point. The Mandl device is on the bottom of the fuselage and looks to be in around the trailing edge of the wing location in the fore and aft sense. The JS-1 vent is on top of the fuselage not far aft of the canopy and it has a little wing in it to get the air to flow along the surface better. The JS-1 location is likely a lower pressure area (top of wing and fat part of fuselage) than the lower fuselage lined up with the wing TE where the pressure is about back to static pressure. Also the Mandl extractor doesn't seem to try to flow the exit air parallel to the airstream. Some tests with dye or tufts would be interesting as well as static pressure measurements. Don't forget also if you manage to put the vent in a low pressure area and close the inlet, cockpit pressure will be a fair bit lower than outside - maybe up to 100 feet or so altitude equivalent with consequent effects on the pressure altitude measured by your logger. This is by no means a new idea to have an exit vent. Wil Schumann used the back of the gear doors as an extractor on his H301b Libelle. I had an exit vent on my Mini Nimbus in 1978. Gliders are coming out with better cockpit ventilation nowadays. It took long enpough. failure to provide adequate ventilation in the cockpit is like failing to provide proper cooling for the engine in a powered aircraft. Mike Borgelt Instruments - design manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com http://www.borgeltinstruments.com/ tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784 : int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] Mandl extractor
The DG website has a thread dating back to 2010 on the (Clemans) Mandl extractor. Go to http://www.dg-flugzeugbau.de/mandl-absaugung-e.html#Zulassung then scroll to the top of the loaded page for the start of the thread and some interesting comments by Holger Back along with the device's background. Best regards, Brian DuRieu From: Anthony Smith anthony.sm...@adelaide.on.net To: 'Discussion of issues relating to Soaring in Australia.' aus-soaring@lists.internode.on.net Sent: Tuesday, 5 June 2012 7:12 PM Subject: Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it? Air into the cockpit must equal air out. If you are ramming air into the cockpit and do not have a suitable exit, where does it go? Predominantly out around the edges of the canopy and worse still along through the wing roots and out the air brake box. In ‘very bad’ examples it is the equivalent of having the airbrakes unlocked (but not open) which is enough of a performance drop to be noticeable to the pilot. The solution is to provide a ‘nice’ way of exiting the air without disturbing the surface flow too much. The JS1 idea is very neat, but complex. The DG way is relatively crude. In older types , an air extractor is a way of getting your 34:1 Std Libelle (or similar) a bit back towards the quoted 38:1. Personally, I plan to have an extractor on the Bergfalke behind the (fixed) main wheel. I can’t make the louvers like Jonkers, and detest the crudity of the DG design, so I am playing with the concept of making a true reverse NACA duct (which is NOT the same as having a NACA scoop facing backwards) behind the fixed main wheel. The reason why? It is impossible to completely seal the nose release in the Bergfalke. As I have air coming in continuously, I might as well have somewhere to dump it and the air behind the main wheel is already pretty disturbed (which may actually defeat the reverse NACA concept – the original NACA inlet duct design was for laminar flow). From:aus-soaring-boun...@lists.internode.on.net [mailto:aus-soaring-boun...@lists.internode.on.net] On Behalf Of Mike Borgelt Sent: Tuesday, 5 June 2012 5:44 PM To: Discussion of issues relating to Soaring in Australia. Subject: Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it? At 04:40 PM 5/06/2012, you wrote: Not sure about independent, but Jonker does the same thing for their JS1's, and I've heard of experimental ASW20 mods to add one. http://www.jonkersailplanes.co.za/index.php?pageid=36 -Matthew No the JS-1 vent is not the same as the Mandl extractor although both aim to suck exit air out through a low pressure point. The Mandl device is on the bottom of the fuselage and looks to be in around the trailing edge of the wing location in the fore and aft sense. The JS-1 vent is on top of the fuselage not far aft of the canopy and it has a little wing in it to get the air to flow along the surface better. The JS-1 location is likely a lower pressure area (top of wing and fat part of fuselage) than the lower fuselage lined up with the wing TE where the pressure is about back to static pressure. Also the Mandl extractor doesn't seem to try to flow the exit air parallel to the airstream. Some tests with dye or tufts would be interesting as well as static pressure measurements. Don't forget also if you manage to put the vent in a low pressure area and close the inlet, cockpit pressure will be a fair bit lower than outside - maybe up to 100 feet or so altitude equivalent with consequent effects on the pressure altitude measured by your logger. This is by no means a new idea to have an exit vent. Wil Schumann used the back of the gear doors as an extractor on his H301b Libelle. I had an exit vent on my Mini Nimbus in 1978. Gliders are coming out with better cockpit ventilation nowadays. It took long enpough. failure to provide adequate ventilation in the cockpit is like failing to provide proper cooling for the engine in a powered aircraft. Mike Borgelt Instruments- design manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784 : int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it?
Hi Mike and others! It wasn't only Wil Schuemann who experimented with an air outlet. About 25 years ago Dick Buttler worked with Schleicher to fit an air extractor to his ASW 22. Martin Heide put an air outlet (similar to the Mandl device) on the undercarriage door of his ASH 25 prototype but was unable to measure a pressure difference in the cockpit. This undercarriage door is currently in my workshop in Adelaide. The US Schleicher agent has developed an air extractor for the ASG 29 in close cooperation with Michael Greiner, the designer of the aircraft. It feature a rather substantional funnel which is designed to accelerate the cockpit air prior to entering the free airstream. By doing so the turbulence around the air extractor is reduced and the drag is supposed to be minimised. The big question is whether the drag created by the turbulence around the air extractor is less than the drag caused by the escape of air around the canopy frame. In any case, a performance gain of anywhere near four L/D points is totally unrealistic. If only half true the LS10 would win every competition ... I hasten to add that cockpit ventilation is likely to be improved as the ventilation air can escape without finding its way through the tail boom to the rear of the fuselage. That in itself is an advantage - especially in a country like Australia. Kind regards to all Bernard - Original Message - From: Discussion of issues relating to Soaring in Australia. @lists.internode.on.net To:Discussion of issues relating to Soaring in Australia. Cc: Sent:Tue, 05 Jun 2012 18:13:59 +1000 Subject:Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it? At 04:40 PM 5/06/2012, you wrote: Not sure about independent, but Jonker does the same thing for their JS1's, and I've heard of experimental ASW20 mods to add one. http://www.jonkersailplanes.co.za/index.php?pageid=36 [1] -Matthew No the JS-1 vent is not the same as the Mandl extractor although both aim to suck exit air out through a low pressure point. The Mandl device is on the bottom of the fuselage and looks to be in around the trailing edge of the wing location in the fore and aft sense. The JS-1 vent is on top of the fuselage not far aft of the canopy and it has a little wing in it to get the air to flow along the surface better. The JS-1 location is likely a lower pressure area (top of wing and fat part of fuselage) than the lower fuselage lined up with the wing TE where the pressure is about back to static pressure. Also the Mandl extractor doesn't seem to try to flow the exit air parallel to the airstream. Some tests with dye or tufts would be interesting as well as static pressure measurements. Don't forget also if you manage to put the vent in a low pressure area and close the inlet, cockpit pressure will be a fair bit lower than outside - maybe up to 100 feet or so altitude equivalent with consequent effects on the pressure altitude measured by your logger. This is by no means a new idea to have an exit vent. Wil Schumann used the back of the gear doors as an extractor on his H301b Libelle. I had an exit vent on my Mini Nimbus in 1978. Gliders are coming out with better cockpit ventilation nowadays. It took long enpough. failure to provide adequate ventilation in the cockpit is like failing to provide proper cooling for the engine in a powered aircraft. Mike BORGELT INSTRUMENTS - design manufacture of quality soaring instrumentation since 1978 www.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784 : int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia @lists.internode.on.net Links: -- [1] http://www.jonkersailplanes.co.za/index.php?pageid=36 ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it?
Hank Nixon built the ASW24/W27/W28/G29 kits now approved by Schleicher at his shop in New Jersey. It can be found on USA Schleicher rep John Murray's website. http://www.easternsailplane.com/eastern/eastern.php/EasternSailplane/TheVent I had theNixon/Murray/Butler ventinstalled in the 27. The same shop has installed the kit in an LS8. The kit has a large removable funnel which slots into the vent and covers the baggage compartment (yet a 6 litre MSR Dromedary Bag still fits).Doubt it does anything for technical performance, but the air flow through the cockpit is greatly improved. The dark side, negative pressure will find anywhere that the cockpit isn't sealed and pull cold outside air in. Now we've used the Streifeneder canopy seal mod (4mm x 0.5mm silicone tubing in a routed slot around the canopy) and it's one of the best sealed gliders I've flown. As Mike pointed out, these ideas have been around for a while. Nimbus 3 ex- VH-VJS had an exhaust vent in the bottom of the rudder, which I thought was a Wil Scheuemann designed mod. Believe it worked well... Never tried flying with the exhaust taped up. The least expensive vent mod is the Quiet Vent by John Bumper Morgan. Adheres to the inside of the vent in the canopy window, smoothing the airflow and cutting down on noise. Works well in conjunction with the exhaust vent, and installs in a minute. For a laugh, look at the Eastern Sailplane catalog pages, click Sailplanes. You can add ASG29s, ASH30s, etc to your shopping cart with a buy now button. Jim From: ec...@internode.on.net ec...@internode.on.net To: Discussion of issues relating to Soaring in Australia. aus-soaring@lists.internode.on.net Sent: Tuesday, June 5, 2012 4:32 AM Subject: Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it? Hi Mike and others! It wasn't only Wil Schuemann who experimented with an air outlet. About 25 years ago Dick Buttler worked with Schleicher to fit an air extractor to his ASW 22. Martin Heide put an air outlet (similar to the Mandl device) on the undercarriage door of his ASH 25 prototype but was unable to measure a pressure difference in the cockpit. This undercarriage door is currently in my workshop in Adelaide. The US Schleicher agent has developed an air extractor for the ASG 29 in close cooperation with Michael Greiner, the designer of the aircraft. It feature a rather substantional funnel which is designed to accelerate the cockpit air prior to entering the free airstream. By doing so the turbulence around the air extractor is reduced and the drag is supposed to be minimised. The big question is whether the drag created by the turbulence around the air extractor is less than the drag caused by the escape of air around the canopy frame. In any case, a performance gain of anywhere near four L/D points is totally unrealistic. If only half true the LS10 would win every competition ... I hasten to add that cockpit ventilation is likely to be improved as the ventilation air can escape without finding its way through the tail boom to the rear of the fuselage. That in itself is an advantage - especially in a country like Australia. Kind regards to all Bernard - Original Message - From: Discussion of issues relating to Soaring in Australia. @lists.internode.on.net To:Discussion of issues relating to Soaring in Australia. Cc: Sent:Tue, 05 Jun 2012 18:13:59 +1000 Subject:Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it? At 04:40 PM 5/06/2012, you wrote: Not sure about independent, but Jonker does the same thing for their JS1's, and I've heard of experimental ASW20 mods to add one. http://www.jonkersailplanes.co.za/index.php?pageid=36 -Matthew No the JS-1 vent is not the same as the Mandl extractor although both aim to suck exit air out through a low pressure point. The Mandl device is on the bottom of the fuselage and looks to be in around the trailing edge of the wing location in the fore and aft sense. The JS-1 vent is on top of the fuselage not far aft of the canopy and it has a little wing in it to get the air to flow along the surface better. The JS-1 location is likely a lower pressure area (top of wing and fat part of fuselage) than the lower fuselage lined up with the wing TE where the pressure is about back to static pressure. Also the Mandl extractor doesn't seem to try to flow the exit air parallel to the airstream. Some tests with dye or tufts would be interesting as well as static pressure measurements. Don't forget also if you manage to put the vent in a low pressure area and close the inlet, cockpit pressure will be a fair bit lower than outside - maybe up to 100 feet or so altitude equivalent with consequent effects on the pressure altitude measured by your logger. This is by no means a new idea to have an exit vent. Wil Schumann used the back of the gear doors as an
Re: [Aus-soaring] Mandl extractor - Is it snake oil or isthere something to it?
More like: a robust platform that allows easy minor alterations for those inlcined to have a go. On Wed 06/06/12 9:32 AM , Derek drudd...@iinet.net.au sent: Did someone mention silk purses? FROM: aus-soaring-boun...@lists.internode.on.net [mailto:aus-soaring-boun...@lists.internode.on.net] ON BEHALF OF Anthony Smith SENT: Tuesday, 5 June 2012 7:43 PM TO: 'Discussion of issues relating to Soaring in Australia.' SUBJECT: Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it? Air into the cockpit must equal air out. If you are ramming air into the cockpit and do not have a suitable exit, where does it go? Predominantly out around the edges of the canopy and worse still along through the wing roots and out the air brake box. In ‘very bad’ examples it is the equivalent of having the airbrakes unlocked (but not open) which is enough of a performance drop to be noticeable to the pilot. The solution is to provide a ‘nice’ way of exiting the air without disturbing the surface flow too much. The JS1 idea is very neat, but complex. The DG way is relatively crude. In older types , an air extractor is a way of getting your 34:1 Std Libelle (or similar) a bit back towards the quoted 38:1. Personally, I plan to have an extractor on the Bergfalke behind the (fixed) main wheel. I can’t make the louvers like Jonkers, and detest the crudity of the DG design, so I am playing with the concept of making a true reverse NACA duct (which is NOT the same as having a NACA scoop facing backwards) behind the fixed main wheel. The reason why? It is impossible to completely seal the nose release in the Bergfalke. As I have air coming in continuously, I might as well have somewhere to dump it and the air behind the main wheel is already pretty disturbed (which may actually defeat the reverse NACA concept – the original NACA inlet duct design was for laminar flow). FROM: aus-soaring-boun...@lists.internode.on.net [1] [mailto:aus-soaring-boun...@lists.internode.on.net] [2] ON BEHALF OF Mike Borgelt SENT: Tuesday, 5 June 2012 5:44 PM TO: Discussion of issues relating to Soaring in Australia. SUBJECT: Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it? At 04:40 PM 5/06/2012, you wrote: Not sure about independent, but Jonker does the same thing for their JS1's, and I've heard of experimental ASW20 mods to add one. http://www.jonkersailplanes.co.za/index.php?pageid=36 [3] -Matthew No the JS-1 vent is not the same as the Mandl extractor although both aim to suck exit air out through a low pressure point. The Mandl device is on the bottom of the fuselage and looks to be in around the trailing edge of the wing location in the fore and aft sense. The JS-1 vent is on top of the fuselage not far aft of the canopy and it has a little wing in it to get the air to flow along the surface better. The JS-1 location is likely a lower pressure area (top of wing and fat part of fuselage) than the lower fuselage lined up with the wing TE where the pressure is about back to static pressure. Also the Mandl extractor doesn't seem to try to flow the exit air parallel to the airstream. Some tests with dye or tufts would be interesting as well as static pressure measurements. Don't forget also if you manage to put the vent in a low pressure area and close the inlet, cockpit pressure will be a fair bit lower than outside - maybe up to 100 feet or so altitude equivalent with consequent effects on the pressure altitude measured by your logger. This is by no means a new idea to have an exit vent. Wil Schumann used the back of the gear doors as an extractor on his H301b Libelle. I had an exit vent on my Mini Nimbus in 1978. Gliders are coming out with better cockpit ventilation nowadays. It took long enpough. failure to provide adequate ventilation in the cockpit is like failing to provide proper cooling for the engine in a powered aircraft. Mike BORGELT INSTRUMENTS - design COLOR: bluewww.borgeltinstruments.com tel: 07 4635 5784 overseas: int+61-7-4635 5784 mob: 042835 5784 : int+61-42835 5784 P O Box 4607, Toowoomba East, QLD 4350, Australia Links: -- [1] mailto:aus-soaring-boun...@lists.internode.on.net [2] mailto:[mailto:aus-soaring-boun...@lists.internode.on.net] [3] http://www.jonkersailplanes.co.za/index.php?pageid=36 ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
Re: [Aus-soaring] Mandl extractor - Is it snake oil or is there something to it?
There have been other enhancements to gliders in the previous century which offered theoretical improvements in performance. There was a spontaneous outbreak of aileron fences in the mid seventies, and serious consideration was given to fairings at the wing fuselage junctions for Libelles. I seem to recall that George Moffat started this with similar mods to the Nimbus 2 he flew at the Waikerie World comps in '74. I do remember trying to photograph a Libelle with tufts of wool in strategic areas and flown by Tim Knappstein from a chase plane (Minicab) in a particularly hilarious exercise during which Tim held up cards indicating his airspeed at that point, while we moved in to record the effects (if any). It was not a success, whether through failure of the photographic records or some other factor, I never really discovered. In the end it was easier to buy an up market aircraft which Tim eventually did - with good results at the Renmark National a few years later. As one pilot remarked (of aileron fences) at the time If you really believe that it gives you an edge, then it probably does regards, TN ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
[Aus-soaring] Solar plane completes maiden intercontinental trip
Intercontinental from Spain to Morocco. Might have been easier to hit the milestone by going from Gibraltar to Ceuta :) http://www.abc.net.au/news/2012-06-06/solar-plane-completes-maiden-intercontinental-trip/4054898 Now let's see them do London to New York. Might need to take a packed lunch or three. - mark ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
[Aus-soaring] Nigerian Glider(?)
http://www.theaustralian.com.au/news/breaking-news/witnesses-describe-nigerian-planes-death-plunge/story-fn3dxity-1226386187110 what are the odds the aircraft ran out of fuel...? ___ Aus-soaring mailing list Aus-soaring@lists.internode.on.net To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
