Narrative:

Incident report on my off field landing in small aircraft. Detailed description of a weekend flight to nantucket, ma. I departed nashua, nh, 4/89 at xy am after preflight and visibility external fuel check. Fuel was full. I climbed straight south into the bos TCA and leveled off at 7500'. I leaned the mixture and reduced RPM to 2200. I continued direct nantucket, ma, and landed at xx am. I departed nantucket 4/89 at yz am after a walkaround inspection and visibility external fuel check. Fuel was 3/4 in both tanks. I climbed to 5500' and entered the bos TCA. About 5 mi north of logan airport I noticed what seemed to be a power loss.I had to keep raising the nose to maintain altitude. No, ore very slight, RPM drop was indicated on the tachometer. I waited 30 seconds and power restored itself to normal, so I concluded the engine had cleared itself and was back to normal operation. Fuel was 1/2. ATC had east descend to 3500' and below the floor of the TCA. I stayed on bos approach frequency. Fuel was 1/4 on both gauges. 10 mins later, approximately 8 mi north of hanscom field by the wang building, I again experienced a power loss--this time also reinforced by a drop in RPM, rough engine and fuel gauges indicating empty on both tanks. Immediately turned around and headed for hanscom field while I asked for and received hanscom tower frequency from bos approach. I tried to keep the engine running by reducing power and playing with the mixture. It died after 20 seconds at 2000'. I told hanscom tower the airplane was out of fuel and that I would land in a grass field approximately 3 mi north of the airport. I turned final for the field but didn't move much closer to it during my turn because of a strong headwind. I had to increase my speed to penetrate the wind by lowering the nose, aiming for a point 200' short of the field. I lowered the flaps and raised the nose just before impact with a tree line separating the airplane from the field. This gave me some instantaneous lift and enabled me to stay airborne until reaching the field. After clearing the trees I lowered the nose again and gained enough airspeed to make a normal flare and landing. The time was XX55 pm. Endurance in an small aircraft is 4.2 hours under normal conditions and with good pilot technique. I ran out of fuel after only 3.3 engine hours. I believe the conditions were normal and that my pilot techniques are average or above, so I conclude the incident was caused by an equipment fault. Callback conversation with reporter revealed the following: reporter states that the only thing that was unusual about the return flight was that the fuel quantity gauges seemed to go down faster on the last half of tank indication than the first half. There were also some fuel stains on the area of the ramp prior to departure that the passenger in the aircraft noticed but had not mentioned to the pilot. Pilot also cites that an electric cord hangs from the block of the engine and is there so that the block heater may be plugged in during cold WX operation. He didn't know if that could have somehow partly opened the drain valve to the fuel/water separator by the carburetor. Aircraft was restr to local flts the following week with a rapid fuel use noted by instrument pilot. Carburetor removed for inspection.

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Original NASA ASRS Text

Title: SMA SUFFERED FUEL EXHAUSTION. MADE FORCED LNDG OFF ARPT.

Narrative: INCIDENT RPT ON MY OFF FIELD LNDG IN SMA. DETAILED DESCRIPTION OF A WEEKEND FLT TO NANTUCKET, MA. I DEPARTED NASHUA, NH, 4/89 AT XY AM AFTER PREFLT AND VIS EXTERNAL FUEL CHK. FUEL WAS FULL. I CLBED STRAIGHT S INTO THE BOS TCA AND LEVELED OFF AT 7500'. I LEANED THE MIXTURE AND REDUCED RPM TO 2200. I CONTINUED DIRECT NANTUCKET, MA, AND LANDED AT XX AM. I DEPARTED NANTUCKET 4/89 AT YZ AM AFTER A WALKAROUND INSPECTION AND VIS EXTERNAL FUEL CHK. FUEL WAS 3/4 IN BOTH TANKS. I CLBED TO 5500' AND ENTERED THE BOS TCA. ABOUT 5 MI N OF LOGAN ARPT I NOTICED WHAT SEEMED TO BE A PWR LOSS.I HAD TO KEEP RAISING THE NOSE TO MAINTAIN ALT. NO, ORE VERY SLIGHT, RPM DROP WAS INDICATED ON THE TACHOMETER. I WAITED 30 SECS AND PWR RESTORED ITSELF TO NORMAL, SO I CONCLUDED THE ENG HAD CLRED ITSELF AND WAS BACK TO NORMAL OPERATION. FUEL WAS 1/2. ATC HAD E DSND TO 3500' AND BELOW THE FLOOR OF THE TCA. I STAYED ON BOS APCH FREQ. FUEL WAS 1/4 ON BOTH GAUGES. 10 MINS LATER, APPROX 8 MI N OF HANSCOM FIELD BY THE WANG BUILDING, I AGAIN EXPERIENCED A PWR LOSS--THIS TIME ALSO REINFORCED BY A DROP IN RPM, ROUGH ENG AND FUEL GAUGES INDICATING EMPTY ON BOTH TANKS. IMMEDIATELY TURNED AROUND AND HEADED FOR HANSCOM FIELD WHILE I ASKED FOR AND RECEIVED HANSCOM TWR FREQ FROM BOS APCH. I TRIED TO KEEP THE ENG RUNNING BY REDUCING PWR AND PLAYING WITH THE MIXTURE. IT DIED AFTER 20 SECS AT 2000'. I TOLD HANSCOM TWR THE AIRPLANE WAS OUT OF FUEL AND THAT I WOULD LAND IN A GRASS FIELD APPROX 3 MI N OF THE ARPT. I TURNED FINAL FOR THE FIELD BUT DIDN'T MOVE MUCH CLOSER TO IT DURING MY TURN BECAUSE OF A STRONG HEADWIND. I HAD TO INCREASE MY SPD TO PENETRATE THE WIND BY LOWERING THE NOSE, AIMING FOR A POINT 200' SHORT OF THE FIELD. I LOWERED THE FLAPS AND RAISED THE NOSE JUST BEFORE IMPACT WITH A TREE LINE SEPARATING THE AIRPLANE FROM THE FIELD. THIS GAVE ME SOME INSTANTANEOUS LIFT AND ENABLED ME TO STAY AIRBORNE UNTIL REACHING THE FIELD. AFTER CLRING THE TREES I LOWERED THE NOSE AGAIN AND GAINED ENOUGH AIRSPD TO MAKE A NORMAL FLARE AND LNDG. THE TIME WAS XX55 PM. ENDURANCE IN AN SMA IS 4.2 HRS UNDER NORMAL CONDITIONS AND WITH GOOD PLT TECHNIQUE. I RAN OUT OF FUEL AFTER ONLY 3.3 ENG HRS. I BELIEVE THE CONDITIONS WERE NORMAL AND THAT MY PLT TECHNIQUES ARE AVERAGE OR ABOVE, SO I CONCLUDE THE INCIDENT WAS CAUSED BY AN EQUIP FAULT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR STATES THAT THE ONLY THING THAT WAS UNUSUAL ABOUT THE RETURN FLT WAS THAT THE FUEL QUANTITY GAUGES SEEMED TO GO DOWN FASTER ON THE LAST HALF OF TANK INDICATION THAN THE FIRST HALF. THERE WERE ALSO SOME FUEL STAINS ON THE AREA OF THE RAMP PRIOR TO DEP THAT THE PAX IN THE ACFT NOTICED BUT HAD NOT MENTIONED TO THE PLT. PLT ALSO CITES THAT AN ELECTRIC CORD HANGS FROM THE BLOCK OF THE ENG AND IS THERE SO THAT THE BLOCK HEATER MAY BE PLUGGED IN DURING COLD WX OPERATION. HE DIDN'T KNOW IF THAT COULD HAVE SOMEHOW PARTLY OPENED THE DRAIN VALVE TO THE FUEL/WATER SEPARATOR BY THE CARB. ACFT WAS RESTR TO LCL FLTS THE FOLLOWING WEEK WITH A RAPID FUEL USE NOTED BY INSTR PLT. CARB REMOVED FOR INSPECTION.

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.