What happened
On the evening of the accident, Flight 710 was operating a multi-leg route from Chicago to Carbondle, Illinois, with a scheduled stop in Springfield. After arriving at Springfield approximately 45 minutes behind schedule, the crew received weather updates indicating overcast conditions, light rain, and fog. Following an IFR clearance to an altitude of 5,000 feet, the aircraft departed runway 15 at 20:20.
Shortly after takeoff, the flightcrew notified departure control of a minor electrical issue. The aircraft was subsequently cleared to descend to 3,000 feet. During the climb, the crew identified that the left generator had failed and the right generator was unable to maintain a load. As the situation progressed, voltage levels dropped significantly, reaching 22 volts, prompting the crew to deactivate non-essential cabin lighting.
At approximately 20:38, an error occurred when the first officer inadvertently isolated the right generator and its associated bus bar from the DC distribution system. Following this action, the aircraft lost radio communication with air traffic control. As the flight continued toward Carbondale, the captain elected to descend to 2,400 feet as voltage levels fell further to 13 volts. The aircraft eventually struck the ground in an open pasture.
Findings
The investigation determined that the primary cause was the captain's choice to proceed to the distant destination rather than returning to the nearby Springfield airport after losing DC electrical power from both generators. This decision was influenced by psychological factors that resulted in an inadequate assessment of the remaining battery life and the associated risks. Additionally, deficiencies in airline training programs regarding electrical malfunctions and battery endurance contributed to the crew's inability to manage the failure effectively.