Please also consider increased likelihood of something going wrong on these big hot days where you will want to load up to the max. Higher all up weight also means more stress on the launching system (cable break etc).
High density altitude days equal reduced engine power from your launching engine when you will also need a higher TAS for the same IAS. Both factors result in much longer T/O runs and a lower ROC. An abort on the now reduced RWY length available at the higher groundspeed resulting from the higher TAS combined with a higher AUW will demand much more wheel breaking power to avoid the end fence. The lower rate of climb also reduces the available landing options and again the higher TAS for the same IAS gives the higher groundspeed that has to be dissipated somehow in your choosen landing area. These big days usually mean more glider activity to navigate through too. ln my accident, just when I thought I had it all under control the wheel brake bowden cable end stripped off under the load I was applying (I must have been stressed too) and I ran into a storm drain at very low speed but still wrote the glider off. I was very lucky to walk away from the wreck. I have come to the conclusion that water breaks gliders. I have to consider the above on every flight before I decide how much water I might load for optimal speed performance. On 13/07/2013 10:17 AM, "Adam Woolley" <[email protected]> wrote: > I think that's a valid point Anthony, Maurie Bradney suggests in flying > further & faster part 1 - to fly 2-3kg/sq.m heavier if you've got good > chance of having thermal markers at a comp. > > I'm working the polar10.xls spreadsheet atm to try & figure out optimum > loadings, though really just stumbling around. Most text books for memory > have always just said, look at your polar - but w/o ever showing exactly > how to do it.. > > > Cheers, > WPP > > On 13/07/2013, at 12:04, "Anthony Smith" <[email protected]> > wrote: > > > Depends: > > > > Classic MacCready climb and glide theory will predict an optimum wing > > loading for the average climb of a particular day for a particular glider > > type. > > > > More recently, optimum wing loading is also defined by how good you are > at > > finding the good air during the cruise. > > > > When you run a mathematical simulation, you get the classical MacCready > > theory optimum and a second optimum at the heavy wing loading end. > Whether > > the heavy end gives a better x-country speed depends on how much 'good > air > > in the cruise' you factor in (ie pilot skill). > > > > I expect that most of the hot pilots load up to full and then dump > > sufficient water to give them a climb rate in their comfort zone and > then > > go like stink without stopping to turn unless they absolutely have to. > > > > -----Original Message----- > > From: [email protected] > > [mailto:[email protected]] On Behalf Of Adam > > Woolley > > Sent: Saturday, 13 July 2013 8:58 AM > > To: Discussion of issues relating to Soaring in Australia. > > Subject: [Aus-soaring] Optimum wing loadings for climb rates? > > > > G'day All, > > > > Just wondering whether anyone know's how to calculate the optimum wing > > loading for an average climb rate? I've just bought a Ventus 1a (UKM) > and > > need to figure out how to fly optimally with water again! > > > > > > SeeYou, > > WPP > > _______________________________________________ > > Aus-soaring mailing list > > [email protected] > > To check or change subscription details, visit: > > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > > _______________________________________________ > > Aus-soaring mailing list > > [email protected] > > To check or change subscription details, visit: > > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > > _______________________________________________ > Aus-soaring mailing list > [email protected] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring >
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