Accident Overview
On September 18, 2009, at approximately 1810 eastern daylight time, a Mooney M20K, registration N999DJ, sustained substantial damage after departing the runway during landing at Farmville Regional Airport (FVX) in Farmville, Virginia. The aircraft was operated under 14 CFR Part 91 as a personal flight, originating from Enterprise Municipal Airport, Alabama, with an instrument flight rules flight plan. Visual meteorological conditions prevailed at the time. The certificated commercial pilot and the passenger were not injured.
Pilot's Account
The pilot reported that during the landing rollout on runway 21, the engine surged. Prior to the surge, the engine was operating at a low idle of 500 to 600 rpm with the throttle at idle. When the surge occurred, the pilot had already applied left rudder in anticipation of turning left onto the taxiway. The airplane then left the runway, traveled onto sod, and continued turning left through the taxiway area until it struck a hedgerow.
Weather and Runway Information
The pilot reported winds from 210 degrees true at 3 knots. Runway 21 was 4,400 feet long and 75 feet wide. The only taxiway, a left turn to the parking apron, was located approximately 2,800 feet from the runway threshold. The aircraft departed the runway about 1,700 feet short of that taxiway. Additionally, two teardrop-shaped turnabouts were available on the left side of runway 21: one at the approach end and another about 200 feet beyond the departure point.
Post-Accident Examination
An initial inspection by a Federal Aviation Administration (FAA) inspector revealed that the airplane veered left off the runway, crossed a shallow ditch, struck one of the VASI (Visual Approach Slope Indicator) stanchions, then continued left and hit a hedgerow. The aircraft reversed direction and ended up facing the runway. No evidence of braking or skidding was found on the grass.
The cockpit examination showed the throttle control in the fully out position. A preliminary inspection of the engine, throttle, and propeller controls found no anomalies. A review of the aircraft's logbooks revealed no prior history of engine surges. A photograph taken after the accident showed one of the two propeller blades with a twisted tip.
Subsequently, on September 25, 2009, two additional FAA inspectors removed the cowling and examined the engine. They verified that the throttle linkage operated smoothly from fully open to fully closed, with no sticking or binding. The fuel control for the turbocharger also showed no mechanical anomalies or leakage. The propeller pitch control moved smoothly through its full range.
Manufacturer's Statement
In response to a query about possible engine acceleration during rollout, an air safety investigator from the engine manufacturer stated that if the throttle valve is closed, no air can reach the engine unless the throttle valve is opened manually from the cockpit. Reference to FAA-H-8083-25 noted that the fuel/air control unit meters fuel based on mixture control and sends it to the fuel manifold valve at a rate controlled by the throttle.