On December 21, 1999, a Cessna 210 (registration N6561X) operated by Lonesome Dove Aviation, Inc. was involved in an aviation accident near Bulverde, TX. Investigators recorded the probable cause as: The total loss of engine power for an undetermined reason. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 8 related events involving the same aircraft type or operator are linked below.
During a maintenance test flight following an annual inspection and engine cylinder overhaul, the airplane experienced a total loss of engine power on final approach and struck trees and terrain.
Accident Sequence
The accident occurred during a local maintenance test flight that followed the airplane's annual inspection, which included an overhaul of the engine cylinders. While on final approach, the airplane's engine lost all power, causing it to strike trees and the terrain.
Post-Accident Examination
After the accident, a ground run of the engine at maximum power revealed no anomalies that would have prevented normal in-flight operation. The ignition system was checked, and continuity was confirmed at all switch positions. The fuel selector valve was found selected to the right tank. When air pressure was applied to the right fuel line at the right wing root, a stream of blue-colored fuel was ejected from the engine pump inlet line. Both auxiliary tank transfer pumps activated when electrical power was supplied. No open discrepancies were noted in the maintenance records.