Accident Sequence
During an air taxi flight, the commercial pilot obtained a weather briefing via the company computer system and reviewed it with the company chief pilot. Based on the briefing, which did not include icing conditions, the pilot was aware of forecasted weather along the route and at the destination. However, the briefing was incomplete because it omitted in-flight weather advisories, including an AIRMET Zulu indicating moderate icing conditions expected over the flight route.
After takeoff, during the climb to 12,000 ft mean sea level (msl), the airplane encountered light rime ice. The pilot activated the de-ice equipment without any issues. Later, after hearing reports of better weather at a lower altitude, the pilot requested a descent to between 5,000 and 6,000 ft.
Weather Information
During the descent to 6,000 ft msl, while the airplane was clear of ice, it encountered light to moderate icing conditions. The pilot considered turning back to another airport but could not get clearance until closer to the destination. Shortly thereafter, the pilot stated that it felt “like a sheet of ice fell on us” as the airplane encountered severe icing conditions.
The weather information indicated a probability of icing between 5,000 and 9,000 ft over the region and a high threat of supercooled large droplets between 5,000 and 7,000 ft. The airplane, equipped for flight in icing conditions, inadvertently encountered severe icing conditions consistent with supercooled large droplets.
Pilot Actions
The pilot applied full engine power to maintain altitude. The airplane exited the overcast cloud layer about 500 ft above ground level. Because the airplane could not maintain altitude, the pilot chose to execute an off-airport emergency landing.
Aircraft Damage and Icing
During the landing, the landing gear separated; the airplane came to rest upright and sustained substantial damage to the wings and fuselage. The pilot reported no preaccident mechanical malfunctions or failures that would have precluded normal operation, and the airplane was within its maximum gross weight. Structural icing was observed on the airframe after the landing.
Probable Cause
The airplane’s inadvertent encounter with severe icing conditions during descent, which resulted in structural icing, the pilot’s inability to maintain altitude, and an emergency landing. Contributing to the accident was an incomplete preflight weather briefing.