Accident Overview
On September 1, 2013, at about 1100 mountain daylight time, a Cessna 182 airplane, registration N6460A, was substantially damaged when the pilot ditched the aircraft into Hayden Lake following a loss of engine power on approach to Boulder Municipal Airport (BDU), Boulder, Colorado. The pilot reported minor injuries. The flight was conducted under 14 Code of Federal Regulations Part 91 as a local flight originating from BDU at approximately 1035. Visual meteorological conditions prevailed, and no flight plan was filed.
Flight Details
The pilot 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. The airplane was on final approach to runway 8 when the engine lost power. The pilot attempted to restore engine power but was unsuccessful, leading to a ditching in Hayden Lake short of the runway. Conditions at the time were described as a clear sky with light and variable wind.
Investigation
A postaccident engine examination conducted by a National Transportation Safety Board investigator revealed no anomalies consistent with a preimpact failure or malfunction. Approximately 11 gallons of fuel were recovered from the airplane. According to the Pilot's Operating Handbook for this aircraft, up to 5 gallons of fuel is unusable in all flight conditions, with 2 gallons unusable in level flight.
A Federal Aviation Administration (FAA) inspector reported that the pilot had used carburetor heat during the descent after the skydivers left the airplane but did not periodically apply engine power (clear the engine) during the descent. FAA information noted a possibility of serious icing at glide power under those conditions.
FAA Advisory Circular 20-113, "Pilot Precautions and Procedures to be Taken in Preventing Aircraft Reciprocating Engine Induction System and Fuel System Icing Problems," recommends that heat 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, and that power lever advancement be performed periodically during descent to assure that power recovery can be achieved.
Weather and Fuel
Weather conditions recorded at the Rocky Mountain Metropolitan Airport (BJC), located about 9 miles southeast of BDU, at 1047 included an ambient temperature of 21 degrees Celsius and a dew point of 11 degrees Celsius.