THE PILOT-IN-COMMAND'S FAILURE TO MAINTAIN AIRSPEED (VSO) DURING A FORCED LANDING, RESULTING IN AN IN-FLIGHT LOSS OF CONTROL (STALL), AND SUBSEQUENT IN-FLIGHT COLLISION WITH TERRAIN. CONTRIBUTING TO THE ACCIDENT WAS THE PILOT-IN-COMMAND'S IMPROPER POSITIONING OF THE FUEL TANK SELECTOR VALVE RESULTING IN FUEL STARVATION.