Cessna 182 N97596 accident near Broomfield, Colorado

Probable cause

The pilot’s inadvertent flight into icing conditions, which resulted in the accumulation of structural icing and an aerodynamic stall.

NTSB analysis

The pilot reported that, while operating in instrument meteorological conditions, the airplane started accumulating ice on the wings and windshield. He informed air traffic control (ATC) and requested to be diverted. ATC vectored him to a nearby airport for an instrument approach. Following completion of the instrument approach, while the airplane was about 10 ft above ground level, the airplane stalled and then landed hard on the runway. The pilot taxied the airplane to the ramp without further incident. The airplane sustained substantial damage to the fuselage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The Federal Aviation Administration's Pilot's Handbook of Aeronautical Knowledge, FAA-H-8083-25B, provides information and guidance in a section titled, "Stalls," which stated, in part, that "as little as 0.8 millimeter of ice on the upper wing surface increases drag and reduces aircraft lift by 25 percent."

Text from the NTSB. Open the NTSB docket for GAA20CA075 for the full record.