Re: [Aus-soaring] Susi Air crash
Thanks to all for your condolences as a result of the death of our summer tuggie from last year, Tomas Munk. Tomas was a great young man, an excellent pilot and was liked enormously by members and visitors alike at Lake Keepit. Our condolences and deepest sympathy also go to the family of Dave Cootes, the Captain of the flight. Ian Downes Manager Lake Keepit Soaring Club - Original Message - From: tom claffey To: aus-soaring Sent: Sunday, September 11, 2011 11:06 AM Subject: [Aus-soaring] Susi Air crash Sad news from Indonesia. It has been reported that Thomas Munk, Tuggie from Lake Keepit last season was lost in a crash while flying as an F/O. http://www.theage.com.au/national/fears-for-australian-pilot-after-indonesia-crash-20110910-1k2i9.html http://aviation-safety.net/database/record.php?id=20110909-0 Tom -- ___ 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
[Aus-soaring] Vomiting passengers
No nasty lingering smell in the cockpit here but there is the risk of getting it down the back of your shirt :-) http://www.gadling.com/2011/09/13/hang-glider-vomits-repeatedly-from-2-000-feet/___ 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] GPS vs Pressure Altitude
At 10:23 AM 14/09/2011, you wrote: I'm not sure that a mistake and misinformation are quite the same. Essentially they are. The mis-information is the result of the mistake. If the mistake was deliberate it would be dis-information. There is a push at IGC level to use GPS altitude for records above 50,000 feet. Very sensible as the change in pressure with altitude is very small up there. Around a 1/10 of the sea level value. Also for Silver and Gold height gains to be able to use GPS only. Eventually the IGC will get sensible and use it for everything. There will need to be specific testing of the characteristics of the GPS receiver though. They aren't all equal, even quite modern ones, unless set up for flight dynamics and 3D navigation full time and no Dead Reckoning. Mike Borgelt Instruments - manufacturers of quality soaring instruments since 1978 phone Int'l + 61 746 355784 fax Int'l + 61 746 358796 cellphone Int'l + 61 428 355784 email: mborg...@borgeltinstruments.com website: www.borgeltinstruments.com ___ 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] GPS vs Pressure Altitude
I'm not sure that a mistake and misinformation are quite the same. However I am happy to acknowledge that I am human, and to support in full the rest of Mike's comments. The trick to getting an altitude record at present is to fly to a place where the pressure is less than the last record. It doesn't matter much how high that is. Cheers /Tim/ /tra dire e fare c'รจ mezzo il mare/ On 13/09/2011 11:39, Mike Borgelt wrote: In the interests of mis - information being quashed: I was right about GPS vs Pressure altitude(PA). Tim advised me he had GPS and Pressure Altitude transposed in his spreadsheet. So his analysis of flight records now agrees with the theoretical analysis in my article and my manual analysis of the IGC files that a few very helpful people sent me. Thanks again guys. As we fly gliders mostly in summer when it is warmer than ISA, most of the time GPS altitude is greater than PA. Not necessarily so in winter on wave flights. If you find this isn't so it may be because you have an early GPS receiver in the FR with some heavy filtering (early Colibris in particular or weird processing of GPS and PA) or your pressure sensor in the FR is off significantly. It also looks to me like the pressure altitude is the anomaly in Geoff Vincent's Flarm. I'd need a few more files to be sure. If you want to compare GPS and PA do remember to take the offsets into account before takeoff and after landing. In this case the FRs that don't automatically start on movement or climb are probably better. Pressure varies from day to day and the pressure sensor in the FR is fixed to 1013 Hpa reference pressure. If you have an early Colibri don't attempt to use the GPS altitude for final glide calculations. Some other FRs seem to show gaps in the GPS altitude record or in the case of one recent FR design the GPS receiver seems to be one optimised for 2D navigation and ground vehicle dynamics with maybe some dead reckoning of GPS altitude under some circumstances . You can't really use that GPS altitude for final glides either. The CAI 302 traces seemed to be quite good with only the odd gap(Garmin module), the EW Microrecorder seems to have an excellent GPS receiver and I would expect FLARM GPS data to be very good also as the GPS module is one where the user can set it for flight dynamics and full time 3D navigation. Always assuming you have a good antenna location with no shielding by the airframe or your body. This is one of the reasons we use our own GPS module in the B500 and now B800 where we use GPS altitude for final glides. We know how the GPS is set up. The glider cares about geometric altitude for how far it can glide, not PA. PA is a requirement for airspace compliance. In my experience given that the surface pressure will change during the day and the errors inherent in using cockpit statics as well as other problems in electronic pressure sensing, GPS altitude is superior to PA for final glides. Do remember to give yourself a margin as your glider may not really glide as well as assumed in the polar in your electronic final glide computer. In some B800 configurations you'll get a real time display of how well it glides against the assumed polar on every glide. See the article on www.borgeltinstruments.com Mike Borgelt Instruments - manufacturers of quality soaring instruments since 1978 ABN: 75532924542 phone 0746 355784 fax 0746 358796 cellphones 0428 355784 0429 355784 email: mborg...@borgeltinstruments.com website: www.borgeltinstruments.com P.O.Box 4607 Toowoomba East, 4350 Queensland 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] GPS vs Pressure Altitude
Many thanks !! Best Regards, Mike Durrant VH-FQF On 13/09/2011, at 11:39 AM, Mike Borgelt wrote: > > In the interests of mis - information being quashed: > > I was right about GPS vs Pressure altitude(PA). Tim advised me he had GPS and > Pressure Altitude transposed in his spreadsheet. So his analysis of flight > records now agrees with the theoretical analysis in my article and my manual > analysis of the IGC files that a few very helpful people sent me. Thanks > again guys. As we fly gliders mostly in summer when it is warmer than ISA, > most of the time GPS altitude is greater than PA. Not necessarily so in > winter on wave flights. > > If you find this isn't so it may be because you have an early GPS receiver in > the FR with some heavy filtering (early Colibris in particular or weird > processing of GPS and PA) or your pressure sensor in the FR is off > significantly. > > It also looks to me like the pressure altitude is the anomaly in Geoff > Vincent's Flarm. I'd need a few more files to be sure. > > If you want to compare GPS and PA do remember to take the offsets into > account before takeoff and after landing. In this case the FRs that don't > automatically start on movement or climb are probably better. Pressure varies > from day to day and the pressure sensor in the FR is fixed to 1013 Hpa > reference pressure. > > If you have an early Colibri don't attempt to use the GPS altitude for final > glide calculations. Some other FRs seem to show gaps in the GPS altitude > record or in the case of one recent FR design the GPS receiver seems to be > one optimised for 2D navigation and ground vehicle dynamics with maybe some > dead reckoning of GPS altitude under some circumstances . You can't really > use that GPS altitude for final glides either. > The CAI 302 traces seemed to be quite good with only the odd gap(Garmin > module), the EW Microrecorder seems to have an excellent GPS receiver and I > would expect FLARM GPS data to be very good also as the GPS module is one > where the user can set it for flight dynamics and full time 3D navigation. > Always assuming you have a good antenna location with no shielding by the > airframe or your body. > > This is one of the reasons we use our own GPS module in the B500 and now B800 > where we use GPS altitude for final glides. We know how the GPS is set up. > > The glider cares about geometric altitude for how far it can glide, not PA. > PA is a requirement for airspace compliance. In my experience given that the > surface pressure will change during the day and the errors inherent in using > cockpit statics as well as other problems in electronic pressure sensing, GPS > altitude is superior to PA for final glides. Do remember to give yourself a > margin as your glider may not really glide as well as assumed in the polar in > your electronic final glide computer. In some B800 configurations you'll get > a real time display of how well it glides against the assumed polar on every > glide. > > See the article on www.borgeltinstruments.com > > > > Mike > Borgelt Instruments - manufacturers of quality soaring instruments since 1978 > ABN: 75532924542 > phone 0746 355784 > fax 0746 358796 > cellphones 0428 355784 > 0429 355784 > email: mborg...@borgeltinstruments.com > website: www.borgeltinstruments.com > P.O.Box 4607 Toowoomba East, 4350 > Queensland 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
