Cessna 182 N6460A accident near Boulder, Colorado

Probable cause

The pilot's failure to adequately clear carburetor icing, resulting in a loss of engine power on final approach following a descent at idle power.

NTSB analysis

The pilot reported that he had flown a group of skydivers to altitude for an intentional parachute jump about 3 miles north of the airport and was returning for landing at the time of the accident. The airplane was on final approach when the engine lost power. The pilot's attempts to restore engine power were unsuccessful, and he ditched the airplane into a lake short of the runway. The pilot reported using carburetor heat during the descent; however, the pilot did not periodically apply engine power (clear the engine) during the descent. According to FAA Advisory Circular 20-113, Pilot Precautions and Procedures to be Taken in Preventing Aircraft Reciprocating Engine Induction System and Fuel System Icing Problems, "Heat should be applied for a short time to warm the induction system before beginning a prolonged descent with the engine throttled and left on during the descent. Power lever advancement should be performed periodically during descent to assure that power recovery can be achieved." A postaccident engine examination did not reveal any anomalies consistent with a preimpact failure or malfunction. Local weather conditions were conducive to the formation of carburetor icing.

Text from the NTSB. Open the NTSB docket for CEN13LA525 for the full record.