Flight Purpose and Takeoff
The flight was intended to reposition the aircraft to Pittsburgh, Pennsylvania. During the takeoff roll from Buffalo, the No. 1 engine exhibited two to three short power surges. Despite these anomalies, the pilot elected to continue the flight rather than abort.
In-Flight Engine Behavior
After takeoff, the engine ran smoothly with the mixture leaned and engine speed set to 2400 RPM. However, when the pilot further leaned the left mixture, the No. 1 engine began to surge again, exhibiting behavior consistent with fuel starvation.
Precautionary Landing
In response to the renewed surging, the pilot executed a precautionary landing at Clarion Airport. During the landing, while at an indicated airspeed of 60 knots, the aircraft was unable to stop on the runway. It continued rolling off the paved surface, traversed grass, and eventually went over a 10-foot cliff.
Outcome
The source does not specify any further details regarding injuries, aircraft damage, or subsequent events. No cause for the engine surges is stated in the investigation report.