On September 12, 1996, at 2115 central daylight time, a Piper PA-31, N27299, operated by Blackhawk Airways, sustained substantial damage during a forced landing in a bean field as a result of fuel exhaustion. The commercial pilot was not injured. The 14 CFR 91 flight had departed Whiteside County Airport, Sterling, Illinois, and was en route to Janesville, Wisconsin, when it ran out of fuel 12 miles from Janesville. Visual meteorological conditions prevailed and a VFR flight plan was filed. The pilot reported that he had a trip in the morning. He reported that he was running late and was in a hurry. He neglected to check the nacelle tanks for fuel, but he did check the main and auxiliary tanks which were full. He reported that he mistakenly thought he had fuel in the nacelle tanks. He completed the trip and was returning to Janesville, Wisconsin. About 12 miles from the airport both engines quit and he executed a forced landing to a field. The aircraft refueler reported that he did not refuel the nacelle tanks. He reported he was told to top off the main and outboard tanks. Examination of the aircraft revealed that there was no fuel in the fuel tanks.