Narrative:

I was flying my glider in a designated wave window with permission from center. I was climbing well while monitoring my blood oxygenation saturation from time to time with a pulse oxymeter while oxygen was being delivered from a chad oxygen conserving cannula. I was maintaining my saturation well; so I did not switch over to a mask as I climbed higher in the wave. Above 22000 ft my canopy began frosting over despite having my vent blowing on it constantly. At about 23000 ft I decided to change over to the mask to decrease frosting so I could maintain visibility. I very carefully attempted to remove the cannula tubing from the aerox brand flow meter that I have. While attempting to remove the cannula tubing which was quite cold at this point; the flow meter broke in two below the section where the tubing connects to the flow meter. The clear part of the flow meter sheared in two. At this point I turned up the oxygen as high as I could get it and held the end of the cannula tubing over the broken flow meter as tightly as I could. It was very clear when I had a fairly good seal or not. I then opened my spoilers and initiated an immediate descent to lower altitudes and safely landed back where the flight had originated. I was very glad I had taken the high altitude training course and flown in the altitude chamber. It was very helpful. Things I learned. 1) I will never fly wave again without a bail out bottle. 2) in talking with the people at aerox; I was told by them that by regulation I should have been on a mask above 18000 ft. I had a mask in the glider; but did not understand it was mandatory above 18000 ft. I was monitoring my saturation and doing well. I will go to a mask before any flights above 18000 ft in the future. 3) aerox has a new flow meter that they say is much more durable than the current one that I have which broke. It appears much thicker and is tested -50 and to a different tso. They reminded me that the flow meter came with a little yellow card that showed you how to carefully change the tubing. I was doing this; but the device is way too brittle when cold. I recommended to them to send out a notice to the soaring society of america to publish in their magazine that their old flow meter may not be suitable for flight in cold conditions such as wave flying and to recommend their new device. They are still however selling the older thinner style which I had trouble with. 4) wave flying is a very special type of soaring and has a very magical appeal; however it can become quite dangerous suddenly if you have a failure such as I did on this flight. I will always have a backup system from now on on such flights.callback conversation with reporter revealed the following information: reporter specified the unit that failed was an aerox part number 'fmnv.' he stated the material from which it was constructed was a type of plastic (perhaps acrylic) and that it took only modest pressure to precipitate the failure. He advised he was wearing gloves in deference to the temperature (approximately -23C) but had taken them off to perform the switch to the nose/mouth mask wearing only glove liners so as to allow adequate articulation.

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Original NASA ASRS Text

Title: SAILPLANE PILOT REPORTS THAT O2 FLOW METER FAILED WHEN ATTEMPTING TO SWITCH FROM CANNULA TYPE DELIVERY SYSTEM TO THE MASK REQUIRED FOR HIGHER ALTITUDES. CITES INCREASED BRITTLENESS DUE TO COLD TEMPERATURES.

Narrative: I WAS FLYING MY GLIDER IN A DESIGNATED WAVE WINDOW WITH PERMISSION FROM CENTER. I WAS CLIMBING WELL WHILE MONITORING MY BLOOD OXYGENATION SATURATION FROM TIME TO TIME WITH A PULSE OXYMETER WHILE OXYGEN WAS BEING DELIVERED FROM A CHAD OXYGEN CONSERVING CANNULA. I WAS MAINTAINING MY SATURATION WELL; SO I DID NOT SWITCH OVER TO A MASK AS I CLIMBED HIGHER IN THE WAVE. ABOVE 22000 FT MY CANOPY BEGAN FROSTING OVER DESPITE HAVING MY VENT BLOWING ON IT CONSTANTLY. AT ABOUT 23000 FT I DECIDED TO CHANGE OVER TO THE MASK TO DECREASE FROSTING SO I COULD MAINTAIN VISIBILITY. I VERY CAREFULLY ATTEMPTED TO REMOVE THE CANNULA TUBING FROM THE AEROX BRAND FLOW METER THAT I HAVE. WHILE ATTEMPTING TO REMOVE THE CANNULA TUBING WHICH WAS QUITE COLD AT THIS POINT; THE FLOW METER BROKE IN TWO BELOW THE SECTION WHERE THE TUBING CONNECTS TO THE FLOW METER. THE CLEAR PART OF THE FLOW METER SHEARED IN TWO. AT THIS POINT I TURNED UP THE OXYGEN AS HIGH AS I COULD GET IT AND HELD THE END OF THE CANNULA TUBING OVER THE BROKEN FLOW METER AS TIGHTLY AS I COULD. IT WAS VERY CLEAR WHEN I HAD A FAIRLY GOOD SEAL OR NOT. I THEN OPENED MY SPOILERS AND INITIATED AN IMMEDIATE DESCENT TO LOWER ALTITUDES AND SAFELY LANDED BACK WHERE THE FLIGHT HAD ORIGINATED. I WAS VERY GLAD I HAD TAKEN THE HIGH ALTITUDE TRAINING COURSE AND FLOWN IN THE ALTITUDE CHAMBER. IT WAS VERY HELPFUL. THINGS I LEARNED. 1) I WILL NEVER FLY WAVE AGAIN WITHOUT A BAIL OUT BOTTLE. 2) IN TALKING WITH THE PEOPLE AT AEROX; I WAS TOLD BY THEM THAT BY REGULATION I SHOULD HAVE BEEN ON A MASK ABOVE 18000 FT. I HAD A MASK IN THE GLIDER; BUT DID NOT UNDERSTAND IT WAS MANDATORY ABOVE 18000 FT. I WAS MONITORING MY SATURATION AND DOING WELL. I WILL GO TO A MASK BEFORE ANY FLIGHTS ABOVE 18000 FT IN THE FUTURE. 3) AEROX HAS A NEW FLOW METER THAT THEY SAY IS MUCH MORE DURABLE THAN THE CURRENT ONE THAT I HAVE WHICH BROKE. IT APPEARS MUCH THICKER AND IS TESTED -50 AND TO A DIFFERENT TSO. THEY REMINDED ME THAT THE FLOW METER CAME WITH A LITTLE YELLOW CARD THAT SHOWED YOU HOW TO CAREFULLY CHANGE THE TUBING. I WAS DOING THIS; BUT THE DEVICE IS WAY TOO BRITTLE WHEN COLD. I RECOMMENDED TO THEM TO SEND OUT A NOTICE TO THE SOARING SOCIETY OF AMERICA TO PUBLISH IN THEIR MAGAZINE THAT THEIR OLD FLOW METER MAY NOT BE SUITABLE FOR FLIGHT IN COLD CONDITIONS SUCH AS WAVE FLYING AND TO RECOMMEND THEIR NEW DEVICE. THEY ARE STILL HOWEVER SELLING THE OLDER THINNER STYLE WHICH I HAD TROUBLE WITH. 4) WAVE FLYING IS A VERY SPECIAL TYPE OF SOARING AND HAS A VERY MAGICAL APPEAL; HOWEVER IT CAN BECOME QUITE DANGEROUS SUDDENLY IF YOU HAVE A FAILURE SUCH AS I DID ON THIS FLIGHT. I WILL ALWAYS HAVE A BACKUP SYSTEM FROM NOW ON ON SUCH FLIGHTS.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER SPECIFIED THE UNIT THAT FAILED WAS AN AEROX PART NUMBER 'FMNV.' HE STATED THE MATERIAL FROM WHICH IT WAS CONSTRUCTED WAS A TYPE OF PLASTIC (PERHAPS ACRYLIC) AND THAT IT TOOK ONLY MODEST PRESSURE TO PRECIPITATE THE FAILURE. HE ADVISED HE WAS WEARING GLOVES IN DEFERENCE TO THE TEMPERATURE (APPROX -23C) BUT HAD TAKEN THEM OFF TO PERFORM THE SWITCH TO THE NOSE/MOUTH MASK WEARING ONLY GLOVE LINERS SO AS TO ALLOW ADEQUATE ARTICULATION.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.