Following to 2022 first measurements & findings using XC vario, I have bought two TE probes from ESA systems last winter, to be flown & recorded over 2023 season. Venturi is the TE probes I have flown over years, it was my reference TE-RU is the "standart" bent TE antenna. It can be installed on tail either pointing up or down TE-DN is the double-head type of TE antenna. It can be installed either vertically either horizontally It means the same glider can be flown in 5 differents TE Antenna configurations, for comparison purpose. It is a bit difficult to judge from reading the ins ..read more

 Yaw string is a basic "equipement" of our gliders, that often questions the people out of gliding movement. My answer to such inquiry is to say "this is a low cost sideslip sensor" - with a tongue in cheek... Well yes yawstring relates to sideslip, but at the end do we really know how much the angle we observe  every flight relates to sideslip ? Yaw string under control... First let's define sideslip : it is as a convention the angle between the speed vector projected into wing plane & fuselage axis - a complicated way to describe that it quantify how much sideways the ..read more

As XC Vario is recording the different pressures available on my glider, namely static PS, dynamic pressure Q & TE probe PTE, it is possible to study them. Anemometric calibration curve of LS6 being quite good, as showing low error of IAS vs CAS, it means in particular than static measuremnt is of good quality. DLR-measured anemo calibration curves for LS6 (1986) As a result, it is possible to build TE pressure coefficient with a reasonable confidence in the absolute level. TE pressure coefficient is defined as follows : CP_TE=(PTE-PS)/Q To have a good compensation antenna, value ..read more

 In August this year, I had a bit of a rough landing, or at least it felt as such. It was the classical LS6 trap : too slow on final approach with Landing flap configuration extended, resulting into nose up attitude in flare to compensate for quasi-stalled status, and tails hitting the ground first. During 2022 season, quite a lot of data was recorded using the XC vario installed on the LS6. I have taken here the opportunity to have a survey on glider parameter during some of the landings, with the objective to analyse the specific rough landing event. In a first plot, indicated airspeed ..read more

 With XCVario, several speeds are measured : True AirSpeed (TAS) can be reconstructed from dynamic pressure & temperature measurements. GPS measurement (from FLARM at this stage) gives direct access to Ground Speed (GS)  --> Difference between both TAS & GS is then an estimate of instantaneous wind in direction of flight. As an illustration for this, the difference between TAS & GS is plotted during final landing phase, representing earth boundary layer above the airfield. A few observations can be made On the 8th of may : Both landings show a reclined boundary la ..read more

Temperature as well as static pressure are measured by XC vario. As a results, it is possible to plot temperature as function of pressure altitude.  Below are plotted a few time slices as recorded. Several observation can be made : Flying straight in sink or neutral zone results in measuring a certain gradient of temperature versus altitude - generally steeper than -6.5deg standart atmosphere gradient. Circling & climbing in a thermal shows a similar temperature gradient versus altitude compared to measured in straight flight, but with an offset corresponding to warmer air While ent ..read more

 As described in the former post, XCVario has onboard sensors of interest to analyse flight paths of a glider. With two other pilots, Jean-Luc & Guy-François, we are working on formulas & algorithms using those sensors to provide enhanced variometry measurement. As a first step, Jean-Luc & Guy-François have created a fork from XCVario software, that is providing in particular the emission on Bluetooth for parameters of interest, that can be recorded by a smartphone. Over the season, I could record more than a ten of flight hour on my LS6 glider, that can be analysed on over t ..read more

 At the begining of the season, I had dismantled the old C302 vario & have replaced it with a modern instrument : A XC Vario. The old generation out... ... replaced by a modern tool ! XCVario is in the family of open source varios, with the interest that a very neat hardware can be purchased, while software is opened. In the main features : Basic sensors covers pressures (static, total & antenna) & temperatures informations for standart altitude & speeds parameter construction Advanced sensors as options providing as well as 3axis acceleros & gyro ..read more

 A long dream come true : I did fly over the family house in Vercors mountains ! More at : https://www.weglide.org/flight/108138 "Eastern balcony" of Vercors Plateau, as flown staring from the south. "Hauts plateaux" prairies in approach ! Flying over the village of Correncon, and the family house Further north, city of Grenoble, were I was a pupil in the last century ..read more

 In this difficult sanitary period, it became legal to go out for sports as far as you stay in your department. And gliding was recorded as one of this sports ! After logging the day off at work, I took the trailer to Luchon-LFCB to have an out of the ordinary day. This was really worth the logistic effort ! In the season, snow is still very much present, but not blocking convection too much ..read more