Narrative:

My original intention was to fly about 3.5 hours and stop for fuel. This would have put me somewhere in central-to- northern west virginia/virginia for lunch and a top-off with plenty of fuel to make it to bdr. I mentioned this to my friends and asked their opinion. Their response was that since we were picking up such a nice tailwind we could make it all the way to PA, stop for lunch near where the fourth airplane needed to be dropped off, and then continue home. That new goal was determined to be 40N, PA. Using my VFR GPS and my watch, as well as my experience with my tiger, I decided that 40N was possible, and I would get there with my 30-min VFR fuel reserve intact. I agreed to the destination, and pressed on. I have absolutely no faith in the fuel gauges in my tiger. I use my watch exclusively to monitor fuel consumption, and I use my experience with the gauges as a general guideline to account for any unexpected fuel leakage. My technique for switching fuel tanks is to use the first tank for 30 mins, then switch tanks every hour thereafter. This keeps the fuel balance left to right, and assures me that both tanks are always within 30 mins of each other. After my initial departure from bwg, I was so busy reading the maps and watching the WX that I neglected to switch the first tank until 40 mins. This did not concern me at the time. Each subsequent tank switch happened exactly 60 mins later, and I kept a log of all tank changes. After I diverted to 40N, I decided that when I switched to the first tank for the last time I would drain that tank, leaving me 30 mins in the other tank, and I would immediately land. With 25.5 gals useable in each tank and a history of fuel consumption at 10.5 gph, I was calculating being able to use each tank for a minimum of 145 mins, for a total flight time of 4.8 hours. I was fully expecting to drain the first tank at 145 mins. Once this first tank was depleted, I would have 25 mins of fuel available in the other tank. With a high cruise speed of 130 KTS I had a 55 NM radius to cover myself. This would be my 'safety valve' if I had miscalculated. There were plenty of airports in the general area, and the WX at this time was very good VFR. Based on the winds, I calculated that I would arrive at 40N with 4.3 hours total flight time, so I fully expected to land with 30 mins of fuel remaining in 1 fuel tank. Both of my friends landed ahead of me, one 1 hour ahead, the other 20 mins. About 15 mi from my destination, the engine sputtered with the left (first) tank run dry. I switched on the electric fuel pump, and flipped over to the right tank. The engine caught immediately. However, I was very concerned. A quick check of my logs showed that the left tank had run only 130 mins. I was expecting 145 mins. Even worse, my logs showed the right tank was 120 mins! I immediately pulled back to best economy cruise throttles and speed and leaned it out further to within an inch of its life, and queried the GPS for the nearest airport. I relayed my situation to my friends ahead at 40N. Right then, the fuel pressure gauge dropped and the engine sputtered -- I had just become a glider. At this point, I was at 5000 ft AGL and still 10 mi from the airport. There were no other closer airports downwind from me, and we were experiencing a good 10 KT tailwind component. I decided to continue towards coatesville. I called a mayday on the CTAF at 40N, maintained my pitch for best glide, and looked for an area to land. Fortunately, there were numerous open fields in the area, so an emergency landing was not going to likely cause much damage. I shook the airplane around to try and get any remaining fuel into the sumps, and I also switched the tanks back and forth to keep the engine running. Someone was smiling on me, because with all of the above I managed to keep the airplane sputtering until I arrived over the airport at 3000 ft AGL, where I was able to make an uneventful deadstick landing and taxi right up to the fuel truck. The tachometer showed 4.3 hours, exactly as calculated. We pumped 51.2 gallons of fuel into this airplane. My friends and I were dumbfounded. What had happened? They had each put in 42 gallons of fuel into their identical airplanes, yet I managed to run my tanks dry. There were no fuel stains anywhere. Then it hit me -- I had spent at least 1/3 of this trip down on the deck scud running at full bore to try and keep up with them. A quick check of the poh showed that my airplane was able to make that 135 KTS at 2700 RPM while using as much as 13 gallons per hour! While running low, I still had that 10.5 gallons per hour number stuck in my head and had neglected to reference the poh to see how it would affect my fuel consumption. The trip averaged almost 12 gallons per hour. My past history of casualness with fuel consumption by having the luxury of a 51 gallon capacity had come back to bite me. Up to this point, I had never explored the limits of the range of this airplane, therefore, I had never felt the need to review the poh for normal, let alone unusual, circumstances. This luxury and casualness lulled me into a dangerous situation that could have potentially ended up in damage and serious injury. I've learned from this experience, and I will never be so casual about fuel consumption again. By the way, I read all the aviation safety magazines, and I had always wondered how someone could get into a low fuel situation. I never could imagine how it would ever happen to me.

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Original NASA ASRS Text

Title: AN AA5 PLT RAN OUT OF FUEL WHILE ON A XCOUNTRY FLT, BUT MANAGED TO DEADSTICK THE ACFT ONTO HIS DEST RWY WITHOUT DAMAGE. HE HAD MISCALCULATED HIS ACTUAL FUEL USAGE AND DID NOT CONSULT HIS OPERATING MANUAL FOR PLANNING INFO BASED ON HIS FLT TECHNIQUES DURING THIS LEG OF THE JOURNEY.

Narrative: MY ORIGINAL INTENTION WAS TO FLY ABOUT 3.5 HRS AND STOP FOR FUEL. THIS WOULD HAVE PUT ME SOMEWHERE IN CENTRAL-TO- NORTHERN WEST VIRGINIA/VIRGINIA FOR LUNCH AND A TOP-OFF WITH PLENTY OF FUEL TO MAKE IT TO BDR. I MENTIONED THIS TO MY FRIENDS AND ASKED THEIR OPINION. THEIR RESPONSE WAS THAT SINCE WE WERE PICKING UP SUCH A NICE TAILWIND WE COULD MAKE IT ALL THE WAY TO PA, STOP FOR LUNCH NEAR WHERE THE FOURTH AIRPLANE NEEDED TO BE DROPPED OFF, AND THEN CONTINUE HOME. THAT NEW GOAL WAS DETERMINED TO BE 40N, PA. USING MY VFR GPS AND MY WATCH, AS WELL AS MY EXPERIENCE WITH MY TIGER, I DECIDED THAT 40N WAS POSSIBLE, AND I WOULD GET THERE WITH MY 30-MIN VFR FUEL RESERVE INTACT. I AGREED TO THE DEST, AND PRESSED ON. I HAVE ABSOLUTELY NO FAITH IN THE FUEL GAUGES IN MY TIGER. I USE MY WATCH EXCLUSIVELY TO MONITOR FUEL CONSUMPTION, AND I USE MY EXPERIENCE WITH THE GAUGES AS A GENERAL GUIDELINE TO ACCOUNT FOR ANY UNEXPECTED FUEL LEAKAGE. MY TECHNIQUE FOR SWITCHING FUEL TANKS IS TO USE THE FIRST TANK FOR 30 MINS, THEN SWITCH TANKS EVERY HR THEREAFTER. THIS KEEPS THE FUEL BAL L TO R, AND ASSURES ME THAT BOTH TANKS ARE ALWAYS WITHIN 30 MINS OF EACH OTHER. AFTER MY INITIAL DEP FROM BWG, I WAS SO BUSY READING THE MAPS AND WATCHING THE WX THAT I NEGLECTED TO SWITCH THE FIRST TANK UNTIL 40 MINS. THIS DID NOT CONCERN ME AT THE TIME. EACH SUBSEQUENT TANK SWITCH HAPPENED EXACTLY 60 MINS LATER, AND I KEPT A LOG OF ALL TANK CHANGES. AFTER I DIVERTED TO 40N, I DECIDED THAT WHEN I SWITCHED TO THE FIRST TANK FOR THE LAST TIME I WOULD DRAIN THAT TANK, LEAVING ME 30 MINS IN THE OTHER TANK, AND I WOULD IMMEDIATELY LAND. WITH 25.5 GALS USEABLE IN EACH TANK AND A HISTORY OF FUEL CONSUMPTION AT 10.5 GPH, I WAS CALCULATING BEING ABLE TO USE EACH TANK FOR A MINIMUM OF 145 MINS, FOR A TOTAL FLT TIME OF 4.8 HRS. I WAS FULLY EXPECTING TO DRAIN THE FIRST TANK AT 145 MINS. ONCE THIS FIRST TANK WAS DEPLETED, I WOULD HAVE 25 MINS OF FUEL AVAILABLE IN THE OTHER TANK. WITH A HIGH CRUISE SPD OF 130 KTS I HAD A 55 NM RADIUS TO COVER MYSELF. THIS WOULD BE MY 'SAFETY VALVE' IF I HAD MISCALCULATED. THERE WERE PLENTY OF ARPTS IN THE GENERAL AREA, AND THE WX AT THIS TIME WAS VERY GOOD VFR. BASED ON THE WINDS, I CALCULATED THAT I WOULD ARRIVE AT 40N WITH 4.3 HRS TOTAL FLT TIME, SO I FULLY EXPECTED TO LAND WITH 30 MINS OF FUEL REMAINING IN 1 FUEL TANK. BOTH OF MY FRIENDS LANDED AHEAD OF ME, ONE 1 HR AHEAD, THE OTHER 20 MINS. ABOUT 15 MI FROM MY DEST, THE ENG SPUTTERED WITH THE L (FIRST) TANK RUN DRY. I SWITCHED ON THE ELECTRIC FUEL PUMP, AND FLIPPED OVER TO THE R TANK. THE ENG CAUGHT IMMEDIATELY. HOWEVER, I WAS VERY CONCERNED. A QUICK CHK OF MY LOGS SHOWED THAT THE L TANK HAD RUN ONLY 130 MINS. I WAS EXPECTING 145 MINS. EVEN WORSE, MY LOGS SHOWED THE R TANK WAS 120 MINS! I IMMEDIATELY PULLED BACK TO BEST ECONOMY CRUISE THROTTLES AND SPD AND LEANED IT OUT FURTHER TO WITHIN AN INCH OF ITS LIFE, AND QUERIED THE GPS FOR THE NEAREST ARPT. I RELAYED MY SIT TO MY FRIENDS AHEAD AT 40N. RIGHT THEN, THE FUEL PRESSURE GAUGE DROPPED AND THE ENG SPUTTERED -- I HAD JUST BECOME A GLIDER. AT THIS POINT, I WAS AT 5000 FT AGL AND STILL 10 MI FROM THE ARPT. THERE WERE NO OTHER CLOSER ARPTS DOWNWIND FROM ME, AND WE WERE EXPERIENCING A GOOD 10 KT TAILWIND COMPONENT. I DECIDED TO CONTINUE TOWARDS COATESVILLE. I CALLED A MAYDAY ON THE CTAF AT 40N, MAINTAINED MY PITCH FOR BEST GLIDE, AND LOOKED FOR AN AREA TO LAND. FORTUNATELY, THERE WERE NUMEROUS OPEN FIELDS IN THE AREA, SO AN EMER LNDG WAS NOT GOING TO LIKELY CAUSE MUCH DAMAGE. I SHOOK THE AIRPLANE AROUND TO TRY AND GET ANY REMAINING FUEL INTO THE SUMPS, AND I ALSO SWITCHED THE TANKS BACK AND FORTH TO KEEP THE ENG RUNNING. SOMEONE WAS SMILING ON ME, BECAUSE WITH ALL OF THE ABOVE I MANAGED TO KEEP THE AIRPLANE SPUTTERING UNTIL I ARRIVED OVER THE ARPT AT 3000 FT AGL, WHERE I WAS ABLE TO MAKE AN UNEVENTFUL DEADSTICK LNDG AND TAXI RIGHT UP TO THE FUEL TRUCK. THE TACHOMETER SHOWED 4.3 HRS, EXACTLY AS CALCULATED. WE PUMPED 51.2 GALLONS OF FUEL INTO THIS AIRPLANE. MY FRIENDS AND I WERE DUMBFOUNDED. WHAT HAD HAPPENED? THEY HAD EACH PUT IN 42 GALLONS OF FUEL INTO THEIR IDENTICAL AIRPLANES, YET I MANAGED TO RUN MY TANKS DRY. THERE WERE NO FUEL STAINS ANYWHERE. THEN IT HIT ME -- I HAD SPENT AT LEAST 1/3 OF THIS TRIP DOWN ON THE DECK SCUD RUNNING AT FULL BORE TO TRY AND KEEP UP WITH THEM. A QUICK CHK OF THE POH SHOWED THAT MY AIRPLANE WAS ABLE TO MAKE THAT 135 KTS AT 2700 RPM WHILE USING AS MUCH AS 13 GALLONS PER HR! WHILE RUNNING LOW, I STILL HAD THAT 10.5 GALLONS PER HR NUMBER STUCK IN MY HEAD AND HAD NEGLECTED TO REF THE POH TO SEE HOW IT WOULD AFFECT MY FUEL CONSUMPTION. THE TRIP AVERAGED ALMOST 12 GALLONS PER HR. MY PAST HISTORY OF CASUALNESS WITH FUEL CONSUMPTION BY HAVING THE LUXURY OF A 51 GALLON CAPACITY HAD COME BACK TO BITE ME. UP TO THIS POINT, I HAD NEVER EXPLORED THE LIMITS OF THE RANGE OF THIS AIRPLANE, THEREFORE, I HAD NEVER FELT THE NEED TO REVIEW THE POH FOR NORMAL, LET ALONE UNUSUAL, CIRCUMSTANCES. THIS LUXURY AND CASUALNESS LULLED ME INTO A DANGEROUS SIT THAT COULD HAVE POTENTIALLY ENDED UP IN DAMAGE AND SERIOUS INJURY. I'VE LEARNED FROM THIS EXPERIENCE, AND I WILL NEVER BE SO CASUAL ABOUT FUEL CONSUMPTION AGAIN. BY THE WAY, I READ ALL THE AVIATION SAFETY MAGAZINES, AND I HAD ALWAYS WONDERED HOW SOMEONE COULD GET INTO A LOW FUEL SIT. I NEVER COULD IMAGINE HOW IT WOULD EVER HAPPEN TO ME.

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.