I took off from Serres in the french Southern Alps in my Sparrowhawk with the goal to train flying in the upper Maurienne valley which I’m barely knowing. Thermal forcast was 4000m (13.000ft) with 20km/h (10 Kts) West wind, and stronger wind above the convective layer.
Entering in the Maurienne valley, it didn’t look nice so I changed my mind and decided to fly to the south.
I came back to the last good thermal and “fill up” my altitude (4250m / 14.000ft) under the nice cumulus, as it was completely blue southward.
During the smooth glide, over Briançon, the variometer became positive: 0,5m/s (100ft/min), I slowed down, and thinking it could be wave, reversed my track and followed my arriving flying line on the map of the Oudie 3, it climbed continuously. I made out and returns like that, noticing the maximum head wind during the turn was at around 35km/h facing west. I extended the legs to determine where the climb started to become weaker. And so on. Crossing 4000m / 13.000ft I switched my oxygen ON, but I started my flight with the bottle half empty… At 5300m / 13300ft I looked at my oxygen bottle behind me, the pressure was approaching the low of the white arc. I got up to 2m/s climb rate. At 5700m, in 50km/h (30Kts) West wind, I checked again my oxygen pressure: it was reaching the start of the red arc. So I decided to stop the climb and resumed gliding south in order to reach 4000m before my oxygen bottle is empty.
Nothing new in the gliding world, even ultralight: in 2009 Jim Payne made several wave flights with the Sparrowhawk along the Sierra Nevada, one of almost 1000km, but a great achievement for me 😀. I don’t regret having so few oxygen, as I was approaching the FL195 upper permitted limit I would anyway have had to stop the climb soon.
Here a short video of this flight: