Narrative:

On return leg of a solo cross country training flight, at cruise altitude, I had a sharp dizziness sensation, followed by a sleepy feeling. Supplemental oxygen was in use at the time, so I checked connections and flow. Fearful of some kind of contamination of portable oxygen system, I discontinued use and descended to 8500 ft MSL. I began feeling a little better but still felt tired. Decided to land at winslow, az, to get something to eat (hadn't eaten since early am). Had a microwave macaroni meal (airport restaurant closed) and some water. I began to feel better and prepared to continue back to prescott, az. While performing pretkof checks, fatigue feeling began to come back, but decided it wasn't too bad to fly. Climbing out, the feeling intensified a bit, so I opened all the vents and window. Approximately 15 mins after takeoff, I realized how lethargic I was becoming. I made a 180 degree turn back to winslow and trimmed aircraft for 500 FPM descent. I was having a hard time concentrating, and performed everything on checklists step-by-step. I felt a little better as I started to descend, but dizziness began to return descending through 7000 ft MSL (about 1000 ft above traffic pattern altitude). The sleepy feeling returned and I may have blacked out for a second or two, which is when I declared an emergency over CTAF and asked for emergency equipment. I was unsure if a safe landing was possible and suspected carbon monoxide poisoning when my fingers began tingling. Another pilot on the ground at winslow told me the winds and suggested runway 22. As I descended on downwind, I began to feel a lot better and made a normal landing. An ambulance was waiting on the ramp for me when I taxied in, and I was taken to the hospital. The doctor in winslow suggested that it might have been the flu, aggravated by not eating and possible heat exhaustion. All blood tests showed nothing else. I had intended to eat something earlier in the day at my original destination (durango, co), but no restaurant was evident there either. If I had known that, I would have bagged my lunch that day. Get-homeitis was also a factor in departing winslow, but as I realized how my performance was degrading and the danger of continuing, I made the right decision to turn back.

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Original NASA ASRS Text

Title: PLT DIZZINESS AND SLEEPY SENSATION CAUSES RETURN LAND.

Narrative: ON RETURN LEG OF A SOLO XCOUNTRY TRAINING FLT, AT CRUISE ALT, I HAD A SHARP DIZZINESS SENSATION, FOLLOWED BY A SLEEPY FEELING. SUPPLEMENTAL OXYGEN WAS IN USE AT THE TIME, SO I CHKED CONNECTIONS AND FLOW. FEARFUL OF SOME KIND OF CONTAMINATION OF PORTABLE OXYGEN SYS, I DISCONTINUED USE AND DSNDED TO 8500 FT MSL. I BEGAN FEELING A LITTLE BETTER BUT STILL FELT TIRED. DECIDED TO LAND AT WINSLOW, AZ, TO GET SOMETHING TO EAT (HADN'T EATEN SINCE EARLY AM). HAD A MICROWAVE MACARONI MEAL (ARPT RESTAURANT CLOSED) AND SOME WATER. I BEGAN TO FEEL BETTER AND PREPARED TO CONTINUE BACK TO PRESCOTT, AZ. WHILE PERFORMING PRETKOF CHKS, FATIGUE FEELING BEGAN TO COME BACK, BUT DECIDED IT WASN'T TOO BAD TO FLY. CLBING OUT, THE FEELING INTENSIFIED A BIT, SO I OPENED ALL THE VENTS AND WINDOW. APPROX 15 MINS AFTER TKOF, I REALIZED HOW LETHARGIC I WAS BECOMING. I MADE A 180 DEG TURN BACK TO WINSLOW AND TRIMMED ACFT FOR 500 FPM DSCNT. I WAS HAVING A HARD TIME CONCENTRATING, AND PERFORMED EVERYTHING ON CHKLISTS STEP-BY-STEP. I FELT A LITTLE BETTER AS I STARTED TO DSND, BUT DIZZINESS BEGAN TO RETURN DSNDING THROUGH 7000 FT MSL (ABOUT 1000 FT ABOVE TFC PATTERN ALT). THE SLEEPY FEELING RETURNED AND I MAY HAVE BLACKED OUT FOR A SECOND OR TWO, WHICH IS WHEN I DECLARED AN EMER OVER CTAF AND ASKED FOR EMER EQUIP. I WAS UNSURE IF A SAFE LNDG WAS POSSIBLE AND SUSPECTED CARBON MONOXIDE POISONING WHEN MY FINGERS BEGAN TINGLING. ANOTHER PLT ON THE GND AT WINSLOW TOLD ME THE WINDS AND SUGGESTED RWY 22. AS I DSNDED ON DOWNWIND, I BEGAN TO FEEL A LOT BETTER AND MADE A NORMAL LNDG. AN AMBULANCE WAS WAITING ON THE RAMP FOR ME WHEN I TAXIED IN, AND I WAS TAKEN TO THE HOSPITAL. THE DOCTOR IN WINSLOW SUGGESTED THAT IT MIGHT HAVE BEEN THE FLU, AGGRAVATED BY NOT EATING AND POSSIBLE HEAT EXHAUSTION. ALL BLOOD TESTS SHOWED NOTHING ELSE. I HAD INTENDED TO EAT SOMETHING EARLIER IN THE DAY AT MY ORIGINAL DEST (DURANGO, CO), BUT NO RESTAURANT WAS EVIDENT THERE EITHER. IF I HAD KNOWN THAT, I WOULD HAVE BAGGED MY LUNCH THAT DAY. GET-HOMEITIS WAS ALSO A FACTOR IN DEPARTING WINSLOW, BUT AS I REALIZED HOW MY PERFORMANCE WAS DEGRADING AND THE DANGER OF CONTINUING, I MADE THE RIGHT DECISION TO TURN BACK.

Data retrieved from NASA's ASRS site as of July 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.