Flight and Approach Planning
The captain and first officer (FO) departed on a non-revenue flight under instrument flight rules with four passengers destined for Truckee, California. Most of the flight was uneventful. During the descent, air traffic control (ATC) told the flight crew to expect the area navigation (RNAV [GPS]) approach for runway 20. The captain, who was the pilot flying (PF), stated and the FO, the pilot monitoring (PM), calculated and confirmed that runway 20 was too short for the landing distance required at the expected landing weight. Instead of requesting a straight-in approach to the longer runway 11, the captain suggested they take the runway 20 approach and circle to land on runway 11. The FO relayed this to ATC, which approved, and the flight crew accepted the circle-to-land approach. Although the descent checklist required briefing the new approach, and the previous straight-in brief was invalidated, the crew failed to brief the new approach.
Execution of the Circling Approach
ATC instructed the flight crew to hold, but the captain was slow to comply, so the FO began the turn to enter the holding pattern and then informed ATC once established. About 20 seconds later, ATC cleared them for the approach. Before the FO confirmed the clearance, he asked if the captain was ready; the captain said yes. The FO then noted excessive airspeed early in the approach and suggested a 360° turn, but the captain did not acknowledge the excessive airspeed and refused the turn. After visually identifying the airport, the FO told the captain to make a 90° right turn to a heading of approximately 290°, parallel to runway 11 and consistent with manufacturer's procedures for the downwind leg of the circling approach. However, the FO instructed the captain to roll out prematurely, and the captain stopped the turn on a heading of about 233° magnetic – 57° left of the intended downwind course. This early rollout established a course requiring an unnecessarily tight turning radius. When they started the turn to final, the airplane was about 1.3 nautical miles from the maximum circling radius for its approach category.
The FO deployed flaps 45° after confirming with the captain (manufacturer's procedures called for flaps 30° on the downwind leg, but the manufacturer stated that flaps 45° is not prohibited if within flight manual limitations). The airplane's airspeed was 44 knots above the calculated landing reference speed (Vref) of 118 knots. The FO said, “I’m gonna get your speed under control for you,” and likely reduced the throttles, as engine fan speeds (N1) decreased from about 88% to about 28%, and the airplane began to slow from 162 knots. After the FO repeatedly tried to point out the airport, the captain identified it; his difficulty possibly resulted from reduced visibility due to smoke. The FO continuously reassured and instructed the captain throughout the circling approach.
Loss of Control and Impact
On the base leg, about 25 seconds before impact, the FO began repeatedly asking for control of the airplane, but neither pilot verbalized a positive transfer of control as required by the operator’s general operating manual (GOM). It could not be determined who had control after these requests. As the airplane crossed the runway extended centerline maneuvering toward the runway, the FO noted the airplane was too high. One of the pilots fully deployed the flight spoilers, likely to increase sink rate. The airspeed at that time was 135 knots, 17 knots above the Vref based on an erroneous basic operating weight programmed into the flight management system (FMS). About 7 seconds later, the left bank became steeper, and the stall protection system (SPS) stick shaker and stick pusher engaged. The captain asked the FO, “What are you doing,” and the FO again asked to “let [him] have the airplane.” The stick shaker and stick pusher briefly disengaged then engaged again. The airplane then entered a rapid left roll, consistent with a left-wing stall, and impacted terrain. A postcrash fire consumed most of the wreckage. All six occupants – four passengers and two pilots – were killed.