General Aviation News will often reprint US National Transportation Safety Board (NTSB) accident reports, including one dated December 2010 about an accident that involved a Cessna 210 in Abilene (Texas) that caused substantial aircraft damage. According to the accident report, the pilot departed on a 615-nautical mile cross-country flight and he determined that the flight would take around four hours and 15 minutes. So he had around five and a half hours of fuel on-board the aircraft.
Prior to departure, the pilot received a weather briefing; but during the flight, the actual winds (especially the headwinds) were stronger than forecasted. When the pilot was 50 miles from the destination airport, he picked up IFR clearance and began to descend through a solid cloud layer. After breaking through the clouds, he realized he could not land at his destination airport.
His engine then loss power and he switched fuel tanks to get it restarted. The controller asked if he had enough fuel to reach an alternative airport 44 miles away. The pilot said his right fuel take showed it was one-third full, but he lost power again about three miles away from the airport – forcing him to make a landing on a road where the aircraft hit a signpost.
Improper fuel management on the part of the pilot was ruled as the cause of the accident – which goes to show that you cannot assume the weather will be what the forecast says it will be when you are doing your fuel calculations before a flight.