Date: 201705
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 50
Light: Daylight
Aircraft: Light Sport Aircraft
Operator: Personal
Operating under: Part 91
Flight plan: VFR
Mission: Personal
Flight phase: Final Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: Personal
Reporter function: Single Pilot
Reporter qualification: Flight Crew Flight Instructor; Flight Crew Sport / Recreational
Human factors: Situational Awareness; Training / Qualification
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition
Contributing factors: Chart Or Publication; Human Factors
Primary problem: Human Factors

Narrative: I received a standard weather briefing. Good weather and favorable winds all the way. Plotted the course using Foreflight with its moving map display; on an iPad. Program calculated fuel usage from numbers put into the program. Considering weather and fuel burn rate and quantity; I should have had enough fuel for the first leg with at least 30 minutes of fuel remaining. There were a few spots where I flew into head winds; but other times I flew at indicated speed of 95 or more. I kept an eye on the fuel sight tubes and the right tank tends to draw faster. As I approached [destination] it became apparent that I wouldn't have that full 30 minutes worth left over. I closed my flight plan and flight following. When the right tank was empty it started drawing from the left tank fairly quickly. I contacted the Tower and got clearance to enter a left downwind for landing. About 1 mile from the airport; I was over housing; the engine started to cough and then quit. I knew immediately that I had run out of fuel. I stabilized the aircraft; found a field that I thought I could make it to; contacted the tower and told them I was out of fuel. They said I could land on any runway; but I was quickly losing altitude and airspeed. I was over houses at the time; there was a small green field off the right; and power lines right along the edge of the field. I just cleared the power lines; then had to bank sharply right and lose the last 50-75 feet of altitude immediately. Tower was still offering immediate landing; but I would have to cross a freeway. The field was my only hope. Had full flaps deployed. Got on the ground and found it to be very rough. Was able to stop safely about 10 ft from a ditch; with a fence and the freeway on the other side. Contacted the tower to let them know I was okay and plane was not damaged. They called 911 and a sheriff responded within 10 minutes. He asked how I was doing and if plane was damaged. Then he left to find a way into the field. While he was gone I contacted the plane manufacturer to find the best way to tow it. They strongly recommended not towing it because it would probably damage the landing gear. They recommended flying off the field. The tower recommended against this; but there was no way to get it out of the field. Tower made sure I realized I would be fully responsible for the flight. The sheriff and tow truck drivers arrived and told me how rough the field was and that there were a few deep ruts that ran across the field. I put a minimum amount of fuel in to reduce weight. The wind had shifted; and I had to taxi carefully to the other end of the field. I had walked it and knew the takeoff route that I should follow. With full flaps I gave it full throttle; released the brakes; and began my roll. The grass was fairly tall; and there were big hummocks that made for a very rough ride and slow acceleration. Finally the plane lifted off just before I reached the ditch and I got over the fence. Leveled out about 10 ft. above the freeway to pick up speed; and then climbed out normally. Had the tower put glasses on the landing gear to make sure nothing was damaged on the rough takeoff roll. Made a normal landing then with emergency vehicles following. Refueled at that point and after hearing from both the tower and the sheriff; who had talked with FAA; I continued my flight; with one more stop for fuel.Rechecked calculations for fuel burn that evening and found that the numbers I was using; which I had gotten from a website; were wrong. When I found more accurate numbers and recalculated. I found that I didn't really have enough gas to complete this first leg safely. I have since then changed those numbers and recalculated my fuel usage for the trip home. With one additional fuel stop; I can make it to each refueling stop with plenty of fuel left over at each stop.




Synopsis: LSA pilot reported an off-airport landing after a fuel miscalculation led to the tanks running dry.