WPR23LA150

The pilot’s failure to maintain adequate airspeed during an attempted go around, which resulted in a runway excursion and impact with terrain.

The pilot reported he was 2.5 hours into a flight review when the accident occurred. On the last leg of the trip the flight the instructor simulated a runway closure and a diversion to a nearby airport. The pilot verified the favored runway and entered an extended downwind to set up a stable approach. The pilot configured the airplane per the airplane checklist and set his power setting for a torque greater than 10 percent to maintain an airspeed of 80-95 knots indicated airspeed (KIAS). When crossing the runway threshold, the instructor stated there was a simulated obstruction on the runway and instructed the pilot to go around. As the pilot advanced the power, the airplane yawed to the left of the runway centerline. The pilot remembers adding right rudder pressure with no effect. The airplane touched down on the left side of the runway and then departed the runway. The airplane traveled through bushes and scrub trees before coming to rest at the edge of a creek. The pilot and instructor secured the airplane and exited before a small fire engulfed much of the airplane. Although the pilot and instructor did not recall any indication of impending loss of control or an aural stall warning before touchdown, audio recorded from onboard the airplane revealed that during the accident approach an electronic voice called out “Stall. Stall.” three times when the airplane was below 500 ft above ground level (agl), followed by “Airspeed” just before touchdown. During and after touchdown, “Stall. Stall.” sounded four additional times as the airplane decelerated. Recordings from the previous leg also contained stall and airspeed electronic voice call outs before landing. The first-leg landing did not include a go-around. Telemetry data recovered showed airspeeds below the required 80 KIAS during the go around attempt. Airplane data showed that on the last two final approaches the airspeed was below 80 KIAS which is required for a go-around at time stamp 22:55:33 for the previous approach and at 23:51:24 on the accident approach. The airplane’s stall speed when configured to land with full flaps, (Vso) is 65 KIAS. The Pilot’s Operating Handbook (POH) describes a minimum go around speed of 80 KIAS to ensure adequate airflow over the rudder to maintain its effectiveness during a go-around maneuver. It is likely that at the application of go-around power, the airspeed was inadequate to provide the right rudder pressure necessary to overcome the left turning yawing moment that was moving the airplane to the left.

On April 7, 2023, about 1655 Pacific daylight time, a Compagnie Daher TBM 700 airplane (marketed as a TBM 940), N6924G, was substantially damaged when it was involved in an accident near Ashland Municipal Airport-Sumner Parker Field (S03), Ashland, Oregon. The pilot and pilot-rated passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 Instructional flight. The pilot had contracted with the flight instructor to perform his biennial flight review.. The flight was planned as an instrument flight rules trip from Rogue Valley International - Medford Airport (MFR) to Crater Lake/Klamath Regional Airport (LMT), with a return leg back to MFR. On the return flight the instructor simulated a runway closure at MFR and a diversion to Ashland Municipal Airport-Sumner Parker Field (S03). As the airplane approached S03 , the pilot established that the winds favored runway 30. The pilot successfully lowered the landing gear after a simulated gear malfunction and extended the downwind leg to assure a stabilized approach. He confirmed that the landing gear was down, full flaps were extended, and the approach speed was between 80 to 95 KIAS, with an engine torque greater than 10%. The pilot reported that the final approach leg was uneventful. After he crossed the pavement of runway 30, the instructor announced to the pilot that there was a simulated obstruction on the runway and that he should perform a go-around. The pilot advanced engine power to 70% torque and established the airplane in a level flight attitude. He expected to see an increase in airspeed; however, almost immediately the airplane yawed to the left of the runway centerline. He applied right rudder but was unable to correct the movement. The airplane continued to lose altitude and impacted the left side of the runway in a level attitude. The pilot applied full power to abort the landing and perform a go-around, but the airplane continued off the left side of the runway. The airplane traveled through vegetation before it proceeded down a slope, where it contacted bushes and small trees near the edge of a creek. The pilot-side door was obstructed by tree branches and the two pilots exited the passenger door. A small fire ensued, eventually engulfing much of the airplane. From the moment the pilot increased power to terrain impact was approximately 3 to 5 seconds. The pilot reported he had performed a go-around many times in the accident airplane with and without instructors. The pilot and instructor reported they did not recall hearing a stall warning indicator or any indication of impending loss of control. The fuel control cable was observed fractured when the FAA examined the engine. A NTSB materials lab analysis showed that the fracture features were consistent with overstress fracture, with no evidence of progressive fracture, and concluded the cable was damaged during the accident. The airplane was equipped with an L-3 lightweight data recorder (LDR) that was sent to the NTSB recorders lab, where data and audio files from the event were successfully downloaded. During the accident approach, the electronic voice callout “Stall. Stall.” sounded 3 times below 500 ft above ground level (agl), followed by “Airspeed” just before touchdown. During and after touchdown, “Stall. Stall.” sounded 4 additional times as the airplane decelerated. FAA personnel oversaw a download of data from the Pratt and Whitney Flight-Data Acquisition, Storage and Transmission (FAST) box. From time stamp 23:51:29, at an elevation of 1,952 above mean sea level (msl), to time stamp 23:51:34, at an elevation of 1,913 msl, the airspeed was as low as 38 kts. The Vso stall speed for this airplane is 65 KIAS. Weight on wheels data was not available on the accident leg due to the breaker being pulled for the manual gear extension demonstration. On the first leg of the flight, between MFR and LMT, the recorder captured the aural cues “Airspeed and Stall. Stall” at an altitude of 500 ft agl during the landing, when the airspeed was below 70 KIAS. Approach airspeed for the airplane is 85 KIAS. The POH for the airplane, in the section “Go-around with AP [autopilot] OFF,” contained a note that states, “The airplane will tend to yaw to the left when power is applied. Right rudder pressure will be required to maintain coordinated straight flight until the rudder trim can be adjusted.”