CEN16LA093 · SOCATA TBM700

The private pilot was conducting an instrument flight rules business flight to an uncontrolled airport with forecast and reported moderate icing conditions. The pilot reported that he activated the deice systems and then executed an instrument landing system approach to the airport with the autopilot connected. While descending through about 1,200 ft above ground level, the pilot extended the landing gear and lowered the flaps to the takeoff setting and subsequently noticed the airplane shudder. Flight data from the airplane's avionics display revealed that the pilot continued the approach, and while on short final, he retarded the throttle toward idle and then disconnected the autopilot. While approaching the runway threshold, the pilot allowed the airspeed to decrease below the Pilot's Operating Handbook's (POH) minimum-recommended approach speed for icing conditions. The airplane's descent rate then increased, and the airplane banked left. The pilot subsequently applied full throttle, and the airplane impacted the ground 1,463 ft short of the runway threshold, skidded 460 ft, hit a hole, and nosed over.

At the accident site, significant ice accumulation was noted on both of the wings and the stabilizer, including ice buildup aft of the deice boots. Weather data indicated that the flight encountered areas of freezing drizzle and supercooled liquid water. Given this evidence, the airplane likely encountered severe (rather than the forecast moderate) in-flight icing conditions during the approach that exceeded the airplane's anti-ice systems' capabilities and led to the pilot's loss of airplane control. Given the icing conditions, the pilot should have maintained the POH's minimum-recommended approach speed for icing conditions.

Verbatim NTSB analysis and probable cause from the NTSB dataset