Friday, December 5, 2014

Back in the Alps

I had not been flying in the alps since 2009... We came back for 2 weeks in  Aubenasson with the family (like in 2008...).

 

The airfield lies next to the Drome River, south east of Valence.


This is quite a nice place for mixing family & flying, with some days flying, and some days walking in the mountains around !


Saou forest - which provides nice slope just near to the airfield - is quite unique sight.


This year was the opportunity to discover a bit more Vercors mountains, with southern but also northern wind...



In term of big flight, weather was somehow choppy, still at the end of the saty it improves & reasonnably nice flights were possible, to le Verdon or Les ecrins.

I could check a few time that Pic de Bures Mountains is still the same serious-looking  moutain...


I was also happy to get my dad in Aubenasson's club Duodiscus to have a bit of "rock surfing".




 Also thanks to Christophe for letting me his nice Libelle - this was a first for me !



Well, those were nice holydays...

Sunday, December 8, 2013

Flying in Spain -2013

The now classical video from shot in spain in 2013.

Not the best weather ever this year, still some very nice flying experience, with friends or alone. There was a lot of north wind, hence very often wave related phenomenons... A good opportunity to test Butterfly vario !

Monday, February 18, 2013

Winter purchases...

This winter I have baught a new sailplane model, first time in years...  Helios was really a good choice. Amazing to see how are made those new DLG, and flying is superb !
Modern 2.4GHz radioset also now goes with downlink as a basis, that is you can have altimeter & variometer reading on the screen, and sound into an earplug !


More info on Helios : http://www.compositegliders.com/

Also play the game "spot the difference".



I have indeed baught the Butterfly "dream vario". It is very well built, installation of the sensor box requires some care... I will hopefully see in flight how this piece of technology is robust, and actually bring something to my flight technic !
I just hope I won't miss too much the 303 interface for simple but efficient navigation...

Saturday, December 8, 2012

Shots from 2012 v2 : in mountains

Some other shots from flying Pyrénées mountains this year.

Saturday, November 24, 2012

Shots from 2012

A video made from various flights along past season...

Monday, October 22, 2012

Flying with tufts

On a blue thermal day, I spent some time adding whool tufts at wing/fuselage junction of my LS6. Here is the result :


The objective was to visualize flow separation in the root of LS6 glider.

Result : flow in wing fuselage junction is sensitive to aoa & aileron:flap deflection.
It can be observed in stall :
Separation occurs at lower fuselage attitude when flap increase. Tip : visualize this by looking at tail position vs horizon when separation appears.
It can be observed in normal flight :
In straight flight, separation is not visible. Very slight tuft activity on the fuselage sides.
While circling, separation occurs quite often, particularly on the wing inside turn. This is likely driven by the additionnal aerodynamic load brought by aileron offset ut of the turn to keep bank angle.

Next time :
Tufts should be applied on both sides It could be interesting to pull some G's to see what happens

Sunday, April 22, 2012

Water & McCready setting

In the waiting of proper weather, here is a table that was derived while studying McCready ring value of various sailplane, with various wing loading. It gives you an equivalent additional Mc Cready setting to be representative of polar change due to waterballast.


This is the result of numerical investigation filtered by the "TAR"* method. For sure your marvelous onboard computer knows better...

The objective is to provide simple figures, easy to memorize, per family of glider (Club class/15m/18m/20m/unlimited), to be used with "Standart Mc Cready ring" (like the good old time).


Example : today I fill my LS6 with 80L of water. I should consider increasing by 0.4m/s my McCready setting due this additional wing loading - on top of other setting (80/100*0.5m/s=0.4m/s)

Don't hesitate to use this "enhanced rule of thumb" !

(& keep in mind it is always more efficient to have a McCready setting "a bit too less" than "a bit too much"...)




* "TAR"="That's About Right" method - i.e. there is a certain dose of approximation in all this.