Accident Details
A Cessna 172 departed Wilkes-Barre, Pennsylvania, at approximately 2145 local time, destined for Essex, Maryland, a straight-line distance of 125 nautical miles. The pilot-in-command reported a total of 30 gallons of fuel aboard at departure, having purchased 20 gallons at Wilkes-Barre, and estimated a flight duration of 1.75 hours.
According to the aircraft owner's manual, unusable fuel was 2.5 gallons per tank, and the maximum fuel consumption for the O-300-A engine at 2,500 feet above sea level is 12.6 gallons per hour (worst case scenario). Fuel consumption decreases as altitude increases or RPM decreases.
Flight and Engine Failure
Approaching the destination, the pilot descended from 3,500 feet to 1,000 feet, entered the downwind, applied carburetor heat, and initiated a left base turn at 700 feet. He reported that RPM dropped off, and unable to reach the airport, he ditched the aircraft in a river under dark night conditions at approximately 2330 local time.
Post-Crash Examination
A post-crash test run of the engine was inconclusive. Approximately 6 gallons of fuel was recovered from within the right wing fuel tank, with the remaining fluid from both tanks being water.
Meteorological Conditions
Temperature and dew point near the time of the accident were reported as 43°F and 30°F, respectively. Under these conditions, serious carburetor icing conditions may have existed.