What happened
On the morning of the accident, a FAR Part 135 on-demand passenger flight was scheduled to depart at 0900. Due to a lack of confirmation, the pilot did not arrive at the airport until approximately 1005. Upon arrival, the pilot proceeded directly to the twin-engine airplane and boarded the aircraft. Prior to this, a maintenance worker had serviced the engines with oil at 0930 but had inadvertently left the dipstick outside of the right engine filler tube.
Shortly after taxiing approximately five feet, the pilot shut down both engines and exited the aircraft. After being approached by the maintenance worker, the pilot closed the oil flap door, believing it had been left open, and subsequently restarted the engines. The aircraft departed at approximately 1008. Roughly three minutes into the flight, the pilot notified departure control via the Unicom frequency that the aircraft required a return to the airport because of an oil leak and issues with the right engine.
Radar tracking showed the aircraft flying south at 1,800 feet msl, passing over the airport at 1,460 feet msl. Instead of landing on runway 18, the aircraft flew past the airport, entered a left turn, and headed back toward the north. The final radar contact occurred at 1016, showing the aircraft at 1,116 feet msl. The aircraft subsequently struck a harvested cornfield in a steep nose-down attitude. There were 0 fatalities reported in the provided text, though the aircraft was destroyed. Witnesses observed the aircraft flying at a very low altitude before the impact.
Findings
- A maintenance worker failed to replace the dipstick in the correct engine oil filler tube after servicing the engines.
- The pilot was unaware that the dipstick had been left on the wing.
- The pilot attempted to return to the airport following an oil leak caused by the engine malfunction.