Approximately 2-hours after departure on an aerial pipeline patrol flight, the pilot turned on the fuel transfer pump, which transfers fuel from the auxiliary baggage fuel tank to the airplane’s right wing fuel tank. The pilot reported that this was his standard routine, and that it would take about two hours to transfer the fuel from the auxiliary tank to the wing fuel tank. The pilot added that almost 4-hours after departure, the engine “sputtered”; he rocked the wings and noticed that the fuel transfer pump appeared off. He then started the fuel transfer again. The fuel transfer light came on; however, the airplane was too low to wait for the fuel to move to the wing fuel tank and then to the engine. So the pilot elected to perform a forced landing to a field. The airplane collided with several tree branches before impacting the ground and flipping over on to its back. During the forced landing the airplane sustained substantial damage to its right wing, aft fuselage, and top of the vertical stabilizer. The pilot also stated that some time after starting the initial transfer of fuel, the transfer pump apparently turned off, and he didn’t notice it. In the section, Recommendation (How could this accident have been prevented?) on the NTSB pilot/operator aircraft accident/incident report form, the pilot stated that moving the auxiliary fuel gauge and indicator light to the instrument panel; or a fuel flow meter on the instrument panel, would aid the pilot in noticing if the fuel transfer pump was on or fuel was actually transferring from the auxiliary fuel tank.