MOONEY M20K — Ocala, FL

What happened

The commercial pilot and one passenger were departing on runway 36 when the airplane experienced a total loss of engine power about 200 ft above the runway. The pilot announced over the control tower frequency that the engine had lost power and that he intended to land the airplane on runway 26, which was located at the end of and perpendicular to the takeoff runway. According to the passenger and witnesses, the airplane completed a left turn to align with runway 26 before the wings rocked, and it rolled into a 90° left bank and collided with terrain. The passenger and witness observations were consistent with the pilot failing to maintain sufficient airspeed, which resulted in the airplane's wing exceeding its critical angle of attack and an aerodynamic stall.

Data downloaded from a panel-mounted engine monitoring system revealed parameters consistent with engine idle, run-up, taxi, and full takeoff power application. A sudden decrease in engine rpm and manifold pressure from takeoff power was preceded by a rapid decrease in fuel flow. Examination of the wreckage revealed that both the left and right wing fuel tanks contained fuel and that the fuel selector handle was between the "Left Tank" and "Off" placard positions. The engine was placed in a test cell where it started immediately, accelerated smoothly, and ran continuously without interruption.

Computerized axial tomography imagery revealed that the fuel selector valve was positioned between the "Left Tank" and "Right Tank" detent positions and that all three valve ports were open to each other. The difference between the handle's position according to the placard and its actual position indicated that the placard had been displaced relative to the handle, which likely occurred during the impact. Bench flow testing of the fuel selector valve and dynamic engine run testing revealed that the valve would supply adequate fuel for normal engine in the as-found intermediate position.

The computerized axial tomography imagery, engine data, and testing of the engine and the fuel selector valve revealed no evidence of preimpact anomalies and demonstrated that the system components still functioned as designed after the accident. The fuel flow interruption and the loss of engine power shortly after takeoff were likely due to the pilot inadvertently placing the fuel selector in the "Off" position, which likely occurred when he completed the step in the Before Takeoff checklist that called for the fuel selector to be placed on the fullest tank. It is possible that the pilot inadvertently moved the fuel selector from the "Left Tank" position to the "Off" position instead of moving it from the "Right Tank" position to the "Left Tank" position. After the power loss, the pilot likely moved the fuel selector from "Off" to its intermediate as-found position in an attempt to restore engine power.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.