Cessna T210 N6958N accident near Tulsa, Oklahoma

Probable cause

The pilot's decision to take off with a known electrical problem, which resulted in the loss of electrical power, problem with the landing gear extension system, and subsequent runway excursion.

NTSB analysis

The airplane had been sitting on a ramp for 3-4 months before the accident flight. The pilot initially could not start the engine due to a discharged battery but then departed on a cross-country flight after a ground unit was used to start the airplane. After takeoff, the pilot noticed that the radios became silent. He started to troubleshoot the loss of radio communications with no success. He set up to return to the airport and land on the runway. The pilot tried to deploy the flaps and landing gear, but there was no indication that either extended. He stated that he checked to see if the landing gear extended by using the wing-mounted mirrors. The pilot continued the approach. During the landing rollout, the pilot applied right rudder and brakes, but the airplane rolled off the runway into the grass. Postaccident examination of the airplane revealed a collapsed left main landing gear. No mechanical anomalies were noted with the landing gear, and the battery was discharged. It is likely that the discharged battery affected the landing gear extension system. However, it could not be determined if the landing gear collapsed during the accident sequence or if it was not completely extended before landing.

Text from the NTSB. Open the NTSB docket for CEN18LA345 for the full record.