Narrative:

While on a 6.5 mi final approach to land at ZZZ3; the piper archer; of which I was PIC; suffered a power loss and subsequently I was forced to land off airport. There were no injuries or property damage and the only damage to the aircraft was a broken position light on the left wingtip. The cause of the power loss was determined to be fuel exhaustion. I believe the cause of the fuel exhaustion was a combination of improper leaning procedures that led to excessive fuel consumption in combination with a grossly inaccurate left fuel gauge which led me to believe I had enough fuel to land at ZZZ3 with legal fuel reserves. I departed ZZZ1 with 1 private pilot/passenger. We flew to ZZZ2 to pick up 2 passenger for charitable medical air transportation. I use duats flight planner and have the fuel burn set for 9.5 gph. The flight planner calculated the flight from ZZZ2 to ZZZ3 to take 2 hours 42 mins and require 26 gallons of fuel. Good VMC was forecast at ZZZ2 for my time of arrival and I decided I could depart with the fuel that was on board and still land with 1 hour of fuel remaining. This was my first missed opportunity to break the chain of events that led to fuel exhaustion. When I saw that I had less fuel in the tanks than expected; I should have ordered more fuel. I also should have given some thought as to why I didn't have as much fuel as expected after taking on the 10 gallons as planned. During the aircraft's recent annual inspection; a cylinder had to be replaced and the mechanic stated that it appeared to be damaged from over-leaning. He advised the flying club's board of directors that pilots needed to be careful not to over-lean the engine. I took his advice out of context and leaned to a setting relatively rich compared to the normal 50 degrees rich of peak egt setting that I have always used in the past. While I should have realized the fuel burn calculations I use during preflight planning would not be accurate if I didn't use the same recommended leaning procedures I had always used in the past; I never would have guessed the difference in fuel consumption would be 3 gph as it turned out to be. I had departed ZZZ2 on the left fuel tank. I set a timer for 1 hour and switched to the right tank when the timer went off. I set the timer to 1 hour 30 mins for the right tank. With 3 mins remaining on the timer; the right fuel tank ran out of fuel. I switched to the left tank immediately. The right tank should have had 25-30 mins of fuel remaining at the time the tank ran dry. After switching to the left tank; I checked the gauge and it showed 15 gallons remaining. I estimated I would land with 1 hour of fuel remaining as expected. The pilot/passenger sitting in the right front seat stated he too saw that the gauge was reading 15 gallons remaining on the left tank. At this time; I should have recognized that the gauge couldn't possibly be correct. Had I realized that I couldn't possibly have 15 gallons remaining in the left tank; I would have diverted to nearby ZZZ4 for fuel. This; of course; was another link in the chain of events that could have been broken. Approximately 30 mins later; while on the last vector to intercept the localizer for runway 16 (circle to land runway 30); the engine began losing power. I was at 2500 ft MSL and approximately 6.5 mi from ZZZ3. I declared an emergency and advised the controller that I couldn't maintain altitude and was looking for a place to land. I immediately looked at the left fuel gauge and it showed it had 10 gallons of fuel remaining. I briefly began troubleshooting including carburetor heat; left fuel tank selected; mixture and throttle forward. I was in a populated area and quickly abandoned the effort to restore power so I could fly the plane and find a place to land. I landed on a new road adjacent to a subdivision that had not yet been opened and was barricaded at the far end. There was no evidence of a fuel leak to explain the high rate of fuel consumption. The aircraft was dismantled and trailered back to ZZZ3 for reassembly. In hindsight; when the tank ran dry unexpectedly when it should have had 30 mins of fuel available; I should have diverted anyway. I had never run any fuel tank dry in the 13 yrs I've been flying prior to this flight. Fortunately; nobody was hurt.

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Original NASA ASRS Text

Title: A PA28 PLT MADE AN OFF FIELD LNDG FOLLOWING FUEL EXHAUSTION BECAUSE THE ENG WAS NOT LEANED ADEQUATELY AND SO FUEL USAGE WAS HIGHER THAN EXPECTED.

Narrative: WHILE ON A 6.5 MI FINAL APCH TO LAND AT ZZZ3; THE PIPER ARCHER; OF WHICH I WAS PIC; SUFFERED A PWR LOSS AND SUBSEQUENTLY I WAS FORCED TO LAND OFF ARPT. THERE WERE NO INJURIES OR PROPERTY DAMAGE AND THE ONLY DAMAGE TO THE ACFT WAS A BROKEN POS LIGHT ON THE L WINGTIP. THE CAUSE OF THE PWR LOSS WAS DETERMINED TO BE FUEL EXHAUSTION. I BELIEVE THE CAUSE OF THE FUEL EXHAUSTION WAS A COMBINATION OF IMPROPER LEANING PROCS THAT LED TO EXCESSIVE FUEL CONSUMPTION IN COMBINATION WITH A GROSSLY INACCURATE L FUEL GAUGE WHICH LED ME TO BELIEVE I HAD ENOUGH FUEL TO LAND AT ZZZ3 WITH LEGAL FUEL RESERVES. I DEPARTED ZZZ1 WITH 1 PVT PLT/PAX. WE FLEW TO ZZZ2 TO PICK UP 2 PAX FOR CHARITABLE MEDICAL AIR TRANSPORTATION. I USE DUATS FLT PLANNER AND HAVE THE FUEL BURN SET FOR 9.5 GPH. THE FLT PLANNER CALCULATED THE FLT FROM ZZZ2 TO ZZZ3 TO TAKE 2 HRS 42 MINS AND REQUIRE 26 GALLONS OF FUEL. GOOD VMC WAS FORECAST AT ZZZ2 FOR MY TIME OF ARR AND I DECIDED I COULD DEPART WITH THE FUEL THAT WAS ON BOARD AND STILL LAND WITH 1 HR OF FUEL REMAINING. THIS WAS MY FIRST MISSED OPPORTUNITY TO BREAK THE CHAIN OF EVENTS THAT LED TO FUEL EXHAUSTION. WHEN I SAW THAT I HAD LESS FUEL IN THE TANKS THAN EXPECTED; I SHOULD HAVE ORDERED MORE FUEL. I ALSO SHOULD HAVE GIVEN SOME THOUGHT AS TO WHY I DIDN'T HAVE AS MUCH FUEL AS EXPECTED AFTER TAKING ON THE 10 GALLONS AS PLANNED. DURING THE ACFT'S RECENT ANNUAL INSPECTION; A CYLINDER HAD TO BE REPLACED AND THE MECH STATED THAT IT APPEARED TO BE DAMAGED FROM OVER-LEANING. HE ADVISED THE FLYING CLUB'S BOARD OF DIRECTORS THAT PLTS NEEDED TO BE CAREFUL NOT TO OVER-LEAN THE ENG. I TOOK HIS ADVICE OUT OF CONTEXT AND LEANED TO A SETTING RELATIVELY RICH COMPARED TO THE NORMAL 50 DEGS RICH OF PEAK EGT SETTING THAT I HAVE ALWAYS USED IN THE PAST. WHILE I SHOULD HAVE REALIZED THE FUEL BURN CALCULATIONS I USE DURING PREFLT PLANNING WOULD NOT BE ACCURATE IF I DIDN'T USE THE SAME RECOMMENDED LEANING PROCS I HAD ALWAYS USED IN THE PAST; I NEVER WOULD HAVE GUESSED THE DIFFERENCE IN FUEL CONSUMPTION WOULD BE 3 GPH AS IT TURNED OUT TO BE. I HAD DEPARTED ZZZ2 ON THE L FUEL TANK. I SET A TIMER FOR 1 HR AND SWITCHED TO THE R TANK WHEN THE TIMER WENT OFF. I SET THE TIMER TO 1 HR 30 MINS FOR THE R TANK. WITH 3 MINS REMAINING ON THE TIMER; THE R FUEL TANK RAN OUT OF FUEL. I SWITCHED TO THE L TANK IMMEDIATELY. THE R TANK SHOULD HAVE HAD 25-30 MINS OF FUEL REMAINING AT THE TIME THE TANK RAN DRY. AFTER SWITCHING TO THE L TANK; I CHKED THE GAUGE AND IT SHOWED 15 GALLONS REMAINING. I ESTIMATED I WOULD LAND WITH 1 HR OF FUEL REMAINING AS EXPECTED. THE PLT/PAX SITTING IN THE R FRONT SEAT STATED HE TOO SAW THAT THE GAUGE WAS READING 15 GALLONS REMAINING ON THE L TANK. AT THIS TIME; I SHOULD HAVE RECOGNIZED THAT THE GAUGE COULDN'T POSSIBLY BE CORRECT. HAD I REALIZED THAT I COULDN'T POSSIBLY HAVE 15 GALLONS REMAINING IN THE L TANK; I WOULD HAVE DIVERTED TO NEARBY ZZZ4 FOR FUEL. THIS; OF COURSE; WAS ANOTHER LINK IN THE CHAIN OF EVENTS THAT COULD HAVE BEEN BROKEN. APPROX 30 MINS LATER; WHILE ON THE LAST VECTOR TO INTERCEPT THE LOC FOR RWY 16 (CIRCLE TO LAND RWY 30); THE ENG BEGAN LOSING PWR. I WAS AT 2500 FT MSL AND APPROX 6.5 MI FROM ZZZ3. I DECLARED AN EMER AND ADVISED THE CTLR THAT I COULDN'T MAINTAIN ALT AND WAS LOOKING FOR A PLACE TO LAND. I IMMEDIATELY LOOKED AT THE L FUEL GAUGE AND IT SHOWED IT HAD 10 GALLONS OF FUEL REMAINING. I BRIEFLY BEGAN TROUBLESHOOTING INCLUDING CARB HEAT; L FUEL TANK SELECTED; MIXTURE AND THROTTLE FORWARD. I WAS IN A POPULATED AREA AND QUICKLY ABANDONED THE EFFORT TO RESTORE PWR SO I COULD FLY THE PLANE AND FIND A PLACE TO LAND. I LANDED ON A NEW ROAD ADJACENT TO A SUBDIVISION THAT HAD NOT YET BEEN OPENED AND WAS BARRICADED AT THE FAR END. THERE WAS NO EVIDENCE OF A FUEL LEAK TO EXPLAIN THE HIGH RATE OF FUEL CONSUMPTION. THE ACFT WAS DISMANTLED AND TRAILERED BACK TO ZZZ3 FOR REASSEMBLY. IN HINDSIGHT; WHEN THE TANK RAN DRY UNEXPECTEDLY WHEN IT SHOULD HAVE HAD 30 MINS OF FUEL AVAILABLE; I SHOULD HAVE DIVERTED ANYWAY. I HAD NEVER RUN ANY FUEL TANK DRY IN THE 13 YRS I'VE BEEN FLYING PRIOR TO THIS FLT. FORTUNATELY; NOBODY WAS HURT.

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