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...

Shots from 2012 v2 : in mountains

Some other shots from flying Pyrénées mountains this year.

Flying in 2012 part 2 : Mountain from MScherrer on Vimeo.

Shots from 2012

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

Flying in 2012 part 1 : Flat Land from MScherrer on Vimeo.

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 :

 Flying LS6 glider with whool "tufts" from MScherrer on Vimeo.

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

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.

Still in the workshop

This year I am not exactly as early as wished at finishing yearly work on the LS6, already some good day were missed... Now my Pruefer is coming next week, everything should be fine !

 I am getting trained at using my Drift HD camera, interesting fish eye effect in the garage, which seems even more molded around the glider ;-)

French oldies

Not exactly sailplane stuff, nevertheless a few interesting views of french prototypes from the 50's, that I numerized from a VHS owned by Jean-Claude Fayer some years ago.

Rare images for some of them.