Date: 201402
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 50
Light: Daylight
Aircraft: Cessna 170
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Passenger
Flight phase: Cruise
Airspace: Class G ZZZ
ATC / advisory: CTAF ZZZ
Aircraft component: Fuel Tank Cap
Component problem: Improperly Operated
Reporter organization: Personal
Reporter function: Single Pilot; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Human factors: Situational Awareness; Workload; Time Pressure
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: Routine Inspection
Result: Flight Crew Inflight Shutdown; Flight Crew Took Evasive Action; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft; Procedure; Human Factors
Primary problem: Ambiguous

Narrative: I was flying a friend to see the route of an upcoming snowmobile race he was going to be in. I estimated the flight would take 4 hours or less; and had 5 hours flight time with full tanks. I filled up the plane; where the passenger joined. When refueling; I filled up the right wing tank; put the cap on the tank; and then moved to the left wing tank. I filled up the tank; thought I put the cap on the tank; and then put the fuel hose and step ladder away. I paid for the $120 of fuel; waited about 5 minutes; then sumped the tanks. I did a brief for the passenger and then we took off mid morning and flew between the mountain ranges. We turned around and flew back and were heading back to the departure airport. The weather was clear and about -15 C. There was very little snow and most lakes were clear and frozen with roads plowed on them. In cruise; the engine coughed and I gave it full mixture; carb heat on; but the engine died. I established best glide at 70 MPH indicated and headed to a nearby airport; which was close. We [were] unable to reach the airport but I landed without incident on the plowed ice road. No damage of any sort occurred to the plane and there was no traffic on the ice road; and we stopped without incident. Upon getting out of the plane; I checked the tanks and the cap was off the left side wing tank. Both tanks were empty; and we had only flown about 3:20 total. I got fuel for the plane via some 5 gallon cans; and the plane ran fine then. After idling for about 10 minutes without a cough; I took off and flew over to the home airport alone; and landed without incident. The passenger paid for fuel when we filled up then. In the preflight; I do it the same way every time. Normally; when refueling; I do the same. I fill the right wing tank first; put the cap on the tank while I am still there; then move to the left wing tank and do it exactly the same. I wait for about 5 minutes then sump the tanks; do a final walk-around and then fly. I may have been distracted by the arrival of the passenger in this case. I will now add another check to my final walk-around before flight to include a re-check of both fuel caps.




Synopsis: A C-170 pilot failed to secure the left wing tank fuel cap and after taking off with an estimated 5 hours of fuel; the engine stopped after 3:20 hours so he made a successful emergency landing. After adding fuel he flew to his home airport.