Narrative:

Cannula flow adjustment knob on same axis as attaching male fitting. While opening flow knob the male fitting backed out!! This thing nearly killed me!! I filed a flight plan with tlh radio en route from ism to 4a9 requesting direct lgc J73 tlh J20 orl direct ism, FL230. The airplane was fueled to approximately 22 gals in the left tank and 32 in the right. I placed my navigation items in the copilot's seat. As a precaution, I placed a walk-around O2 bottle in the copilot's seat as well. The regular O2 mask that I would wear above 18000 ft was right behind me. WX was severe clear for the entire route. I put the cannula equipment in operation before takeoff and set O2 flow rate at 2.0 lpm. I placed the flow indicator right in front of myself for easy view. In retrospect, it does seem that the flow regulator knob had a stiffness about it. After normal takeoff, I contacted atl ATC and received my clearance as filed, FL230. Somewhere during climb I noticed that the O2 flow had stopped. Trouble shooting the system seemed simple enough and I discovered that the male fitting of the hose had backed out of the aircraft O2 outlet. I replaced it and added a firm clockwise twist or two, to assure that the fitting would not back out again. I asked for FL250 and seem to recall reporting out of FL203 ('20300 at 29.92') as I left that altitude. I do not remember where I discovered the O2 flow stoppage following my reconnection of the hose. I do remember that my reaction was an urgent checking of the main valve on and the fittings firmly in place. (I did not remember the walk-around bottle until the following afternoon!) I realize now that in the effort to ensure that the hose fitting was snug, I had rotated the flow knob to the off position as I tightened the bayonet fitting. I wanted to descend and seem to remember an attempt to put the aircraft into a descent and trying to communicate with center on the current frequency, the last frequency, and finally on 121.5. I did not hear any xmissions from ATC following the clearance to FL250. I cannot recall if I was nauseous at this time or not--I rather think so. It seemed to me that the aircraft had been put into a descent a my vision 'greyed out' from the edges. My next awareness was at about FL130. My first conscious perception was a very dark view through the windshield. My heading was into the sun and I could tell from the sea-state that I was over the gulf. The propeller was windmilling, obviously an empty fuel tank. I reduced the throttle and switched tanks.T he engine started immediately and I turned left to about 060 degrees--an intuitive course change to the closest land from wherever I was. I continued my descent to 2500 ft--wanted to get low enough to breathe heavy air, and yet be high enough to allow some fumbling space for altitude control nausea persisted and I 'lost my lunch.' I became aware that my LORAN was set on ism, and made a heading change toward home. About that time I became aware of an fgt Z(?) off my left wing and of xmissions on 121.5 from a coast guard aircraft (spc west). The coast guard aircraft announced his position and his intentions to take me to pie. I asked for a heading and the coast guard aircraft gave me heading, the pie VOR frequency, and an altimeter setting. Coast guard aircraft stayed with me to pie and gave me information on 121.5 while I worked approach and tower on my #1 communication. The landing was west/O incident and I taxied clear of the runway and to a large group of emergency vehicles. After talking briefly with the FSDO officer, I taxied to the FBO and shut down. The attending ambulance took me to the hospital where I was admitted into icu for extensive tests and observation that lasted through 3/tue/89. During my first night at the hospital the duty officer from the coast guard phoned me. I gave him some information which I thought would be of a confidential nature to fill in his report. Later I heard of fragmented media reports that seemed to be based upon what I had said. Conclusions: 1) I tried to do too many things on 1 flight. My interest in experiencing the cannula system should have been reserved for a single flight totally conducted at a lower altitude,say 13000 or 15000 ft. (And by the way, the owner of the aircraft had reminded me shortly before the flight that the cannula was of a 'lower altitude nature.' 2) my previous extensive experience in high altitude flight in various aircraft lulled me into overlooking the difference between 'familiarity' and 'intimacy.' I am indeed familiar with various system, but I was not intimate with the one that I was using! Further, the onset of hypoxia resulted because my preflight plan of action and provision for contingencies was thwarted by the unexpected disengagement of the cannula hose fitting and my closing of the valve while reinserting the hose connection! 3) the coast guard 'shepherding' service was positive and helpful. However, future answers to phone questions must be 'no comment.'

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Original NASA ASRS Text

Title: PLT OF LIGHT SINGLE ENGINE ACFT, USING WHAT MIGHT POSSIBLY BE AN UNAPPROVED O2 SYSTEM, PASSES OUT FROM HYPOXIA, RECOVERS CONSCIOUSNESS WHEN ACFT, HAVING EXPERIENCED FUEL STARVATION, DESCENDS OUT OF CONTROL TO A LOWER ALT. REPORTER IS INTERCEPT AND ESCORTED TO SAFETY BY THE COAST GUARD.

Narrative: CANNULA FLOW ADJUSTMENT KNOB ON SAME AXIS AS ATTACHING MALE FITTING. WHILE OPENING FLOW KNOB THE MALE FITTING BACKED OUT!! THIS THING NEARLY KILLED ME!! I FILED A FLT PLAN WITH TLH RADIO ENRTE FROM ISM TO 4A9 REQUESTING DIRECT LGC J73 TLH J20 ORL DIRECT ISM, FL230. THE AIRPLANE WAS FUELED TO APPROX 22 GALS IN THE LEFT TANK AND 32 IN THE RIGHT. I PLACED MY NAV ITEMS IN THE COPLT'S SEAT. AS A PRECAUTION, I PLACED A WALK-AROUND O2 BOTTLE IN THE COPLT'S SEAT AS WELL. THE REGULAR O2 MASK THAT I WOULD WEAR ABOVE 18000 FT WAS RIGHT BEHIND ME. WX WAS SEVERE CLEAR FOR THE ENTIRE RTE. I PUT THE CANNULA EQUIP IN OPERATION BEFORE TKOF AND SET O2 FLOW RATE AT 2.0 LPM. I PLACED THE FLOW INDICATOR RIGHT IN FRONT OF MYSELF FOR EASY VIEW. IN RETROSPECT, IT DOES SEEM THAT THE FLOW REGULATOR KNOB HAD A STIFFNESS ABOUT IT. AFTER NORMAL TKOF, I CONTACTED ATL ATC AND RECEIVED MY CLRNC AS FILED, FL230. SOMEWHERE DURING CLB I NOTICED THAT THE O2 FLOW HAD STOPPED. TROUBLE SHOOTING THE SYS SEEMED SIMPLE ENOUGH AND I DISCOVERED THAT THE MALE FITTING OF THE HOSE HAD BACKED OUT OF THE ACFT O2 OUTLET. I REPLACED IT AND ADDED A FIRM CLOCKWISE TWIST OR TWO, TO ASSURE THAT THE FITTING WOULD NOT BACK OUT AGAIN. I ASKED FOR FL250 AND SEEM TO RECALL RPTING OUT OF FL203 ('20300 AT 29.92') AS I LEFT THAT ALT. I DO NOT REMEMBER WHERE I DISCOVERED THE O2 FLOW STOPPAGE FOLLOWING MY RECONNECTION OF THE HOSE. I DO REMEMBER THAT MY REACTION WAS AN URGENT CHKING OF THE MAIN VALVE ON AND THE FITTINGS FIRMLY IN PLACE. (I DID NOT REMEMBER THE WALK-AROUND BOTTLE UNTIL THE FOLLOWING AFTERNOON!) I REALIZE NOW THAT IN THE EFFORT TO ENSURE THAT THE HOSE FITTING WAS SNUG, I HAD ROTATED THE FLOW KNOB TO THE OFF POS AS I TIGHTENED THE BAYONET FITTING. I WANTED TO DSND AND SEEM TO REMEMBER AN ATTEMPT TO PUT THE ACFT INTO A DSCNT AND TRYING TO COMMUNICATE WITH CENTER ON THE CURRENT FREQ, THE LAST FREQ, AND FINALLY ON 121.5. I DID NOT HEAR ANY XMISSIONS FROM ATC FOLLOWING THE CLRNC TO FL250. I CANNOT RECALL IF I WAS NAUSEOUS AT THIS TIME OR NOT--I RATHER THINK SO. IT SEEMED TO ME THAT THE ACFT HAD BEEN PUT INTO A DSCNT A MY VISION 'GREYED OUT' FROM THE EDGES. MY NEXT AWARENESS WAS AT ABOUT FL130. MY FIRST CONSCIOUS PERCEPTION WAS A VERY DARK VIEW THROUGH THE WINDSHIELD. MY HDG WAS INTO THE SUN AND I COULD TELL FROM THE SEA-STATE THAT I WAS OVER THE GULF. THE PROP WAS WINDMILLING, OBVIOUSLY AN EMPTY FUEL TANK. I REDUCED THE THROTTLE AND SWITCHED TANKS.T HE ENG STARTED IMMEDIATELY AND I TURNED LEFT TO ABOUT 060 DEGS--AN INTUITIVE COURSE CHANGE TO THE CLOSEST LAND FROM WHEREVER I WAS. I CONTINUED MY DSCNT TO 2500 FT--WANTED TO GET LOW ENOUGH TO BREATHE HEAVY AIR, AND YET BE HIGH ENOUGH TO ALLOW SOME FUMBLING SPACE FOR ALT CONTROL NAUSEA PERSISTED AND I 'LOST MY LUNCH.' I BECAME AWARE THAT MY LORAN WAS SET ON ISM, AND MADE A HDG CHANGE TOWARD HOME. ABOUT THAT TIME I BECAME AWARE OF AN FGT Z(?) OFF MY LEFT WING AND OF XMISSIONS ON 121.5 FROM A COAST GUARD ACFT (SPC W). THE COAST GUARD ACFT ANNOUNCED HIS POS AND HIS INTENTIONS TO TAKE ME TO PIE. I ASKED FOR A HDG AND THE COAST GUARD ACFT GAVE ME HDG, THE PIE VOR FREQ, AND AN ALTIMETER SETTING. COAST GUARD ACFT STAYED WITH ME TO PIE AND GAVE ME INFO ON 121.5 WHILE I WORKED APCH AND TWR ON MY #1 COM. THE LNDG WAS W/O INCIDENT AND I TAXIED CLR OF THE RWY AND TO A LARGE GROUP OF EMER VEHICLES. AFTER TALKING BRIEFLY WITH THE FSDO OFFICER, I TAXIED TO THE FBO AND SHUT DOWN. THE ATTENDING AMBULANCE TOOK ME TO THE HOSPITAL WHERE I WAS ADMITTED INTO ICU FOR EXTENSIVE TESTS AND OBSERVATION THAT LASTED THROUGH 3/TUE/89. DURING MY FIRST NIGHT AT THE HOSPITAL THE DUTY OFFICER FROM THE COAST GUARD PHONED ME. I GAVE HIM SOME INFO WHICH I THOUGHT WOULD BE OF A CONFIDENTIAL NATURE TO FILL IN HIS RPT. LATER I HEARD OF FRAGMENTED MEDIA RPTS THAT SEEMED TO BE BASED UPON WHAT I HAD SAID. CONCLUSIONS: 1) I TRIED TO DO TOO MANY THINGS ON 1 FLT. MY INTEREST IN EXPERIENCING THE CANNULA SYS SHOULD HAVE BEEN RESERVED FOR A SINGLE FLT TOTALLY CONDUCTED AT A LOWER ALT,SAY 13000 OR 15000 FT. (AND BY THE WAY, THE OWNER OF THE ACFT HAD REMINDED ME SHORTLY BEFORE THE FLT THAT THE CANNULA WAS OF A 'LOWER ALT NATURE.' 2) MY PREVIOUS EXTENSIVE EXPERIENCE IN HIGH ALT FLT IN VARIOUS ACFT LULLED ME INTO OVERLOOKING THE DIFFERENCE BTWN 'FAMILIARITY' AND 'INTIMACY.' I AM INDEED FAMILIAR WITH VARIOUS SYS, BUT I WAS NOT INTIMATE WITH THE ONE THAT I WAS USING! FURTHER, THE ONSET OF HYPOXIA RESULTED BECAUSE MY PREFLT PLAN OF ACTION AND PROVISION FOR CONTINGENCIES WAS THWARTED BY THE UNEXPECTED DISENGAGEMENT OF THE CANNULA HOSE FITTING AND MY CLOSING OF THE VALVE WHILE REINSERTING THE HOSE CONNECTION! 3) THE COAST GUARD 'SHEPHERDING' SVC WAS POSITIVE AND HELPFUL. HOWEVER, FUTURE ANSWERS TO PHONE QUESTIONS MUST BE 'NO COMMENT.'

Data retrieved from NASA's ASRS site as of August 2007 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.