DENVER—A twin-engine plane that crashed east of Colorado Springs last year, killing both people on board, probably lost power because it went into a spin that kept fuel from getting to the engines, a federal aviation investigator said Thursday.
The circumstances of the Aug. 23 crash were very rare, National Transportation Safety Board investigator Jennifer Rodi said.
The plane apparently went into a flat spin, spinning rapidly while remaining level—like a merry-go-round. The centrifugal force likely pushed the fuel away from the two engines and into the wingtip fuel tanks, Rodi said.
Both fuel tanks were split open when the wreckage was examined, an indicator of the pressure caused by the centrifugal force, Rodi said. She said no mechanical problems were found in the fuel system.
Authorities identified the victims as William Boecking, 76, and Daniel Saunders, 60. Both were from Colorado Springs.
Boecking was a commercial pilot and owned the Cessna 310C. Saunders was a flight instructor.
Both were experienced pilots. Boecking had more than 3,400 hours of flying time and Saunders had more than 3,800, the NTSB said.
Rodi said investigators don’t know which man was at the controls at the time of the crash.
Saunders was conducting a routine periodic review of Boecking’s proficiency at the time of the crash. The plane was probably put into an intentional stall, where the wings lose their aerodynamic lift, as part of the review, Rodi said.
A stall can trigger a flat spin under some circumstances, she said.
The plane took off from Meadow Lake Airport in Colorado Springs and crashed a half-hour later about 30 miles to the east.
The NTSB issued a report Wednesday detailing many of Rodi’s findings. A report with a formal determination of the cause will likely be released in two or three months, the investigator said.
