NYC02LA043

The pilot filed an IFR flight plan and received a standard weather briefing, which included a forecast for light snow along the entire route of flight. The briefing also included an AIRMET for occasional moderate rime or mixed ice in clouds and precipitation from 6,000 to 12,000 feet msl, and a PIREP for light rime ice at 5,000 feet msl. About 20 minutes after departure, and cruising in IMC conditions at 5,000 feet for approximately 10 minutes, the pilot observed snow. Several minutes later, the engine lost all power, and the pilot then applied the carburetor heat as part of his restart checklist. The engine did not restart, and the pilot performed a forced landing to trees. FAA Advisory Circular AC 20-113 cautioned pilots of impact ice forming on intake screens and carburetors when flying in snow. The circular advised pilots to use carburetor heat as a preventative measure, rather than as a deicer. After the accident, an FAA inspector attended a test run of the accident engine. The inspector stated that the engine started with no difficulty and ran continuously.

On December 26, 2001, about 1900 eastern standard time, a Cessna 182, N660DD, experienced a total loss of engine power, and was substantially damage during a forced landing, near Falmouth, Kentucky. The certificated commercial pilot sustained minor injuries, and the passenger was not injured. Night instrument meteorological conditions (IMC) prevailed for the flight that departed Bowman Field (LOU) Louisville, Kentucky; destined for Bolton Field (TZR), Columbus, Ohio. An instrument flight rules flight plan was filed for the personal flight conducted under 14 CFR Part 91.

The pilot stated that he departed LOU about 1830, and after climbing to 5,000 feet msl, was in IMC. About 10 minutes later, he noticed "snow that was not forecasted, with no structural icing." About 1900, while all engine gauges were indicating "normal," the airplane experienced a total loss of engine power. The pilot added that there was no sputtering or partial power loss prior to the total loss of engine power.

The pilot advised air traffic control that he had a total loss of engine power, and believed it was due to carburetor ice. He then performed a restart procedure from memory, which included activating the carburetor heat. After completing the checklist from memory, the engine started for 2 seconds, but then lost all power again. Air traffic control provided vectors to the nearest airport, but the airplane struck trees and came to rest. During the forced landing, the airplane sustained damage to the wings and fuselage.

The wreckage was examined by a Federal Aviation Administration inspector. The inspector observed that the right fuel tank contained fuel. The left wing fuel crossover line had ruptured during the accident, and fuel leaked from the left tank. Due to the disposition of the wreckage, the inspector was unable to examine the engine at the accident site. However, several weeks later, the inspector attended a test run of the engine. He stated that the engine started with no difficulty, and ran continuously.

Review of a cassette tape recording of the pilot's weather briefing revealed that the Flight Service Specialist provided a standard weather briefing, and forecasted light snow along the entire route of flight. The specialist stated that there was an AIRMET in effect for occasional moderate rime or mixed ice in clouds and precipitation from 6,000 to 12,000 feet msl. The specialist added that there were several broken cloud layers along the route, and the cloud tops ranged from 8,000 to 10,000 feet msl. Additionally, the pilot of a Piper Cherokee that was flying 25 miles west of LOU provided a PIREP, which included light rime ice at 5,000 feet msl.

NEXRAD radar imagery from Cincinnati, Ohio, recorded at 1908, revealed light to moderate precipitation between LOU and TZR. The reported weather at an airport approximately 20 miles northwest of the accident site, at 1851, was: wind from 270 degrees at 16 knots, gusting to 20 knots; visibility 10 miles; ceiling 9,000 feet overcast; temperature 25 degrees F; dew point 16 degrees F; altimeter 29.81 inches hg.

Review of FAA Advisory Circular AC 20-113 revealed:

"Impact Ice - Impact ice is formed by moisture laden air at temperatures below freezing, striking and freezing on elements of the induction system which are at temperatures of 32 degrees F. or below. Under these conditions, ice may build up on such components as the air scoops, heat or alternate air valves, intake screens, and protrusions in the carburetor. Pilots should be particularly alert for such icing when flying in snow, sleet, rain, or clouds, especially when they see ice forming on the windshield or leading edge of the wings. The ambient temperature at which impact ice can be expected to build most rapidly is about 25 degrees F., when the supercooled moisture in the air is still in a semi liquid state. This type of icing affects an engine with fuel injection, as well as carbureted engines. It is usually preferable to use carburetor heat or alternate air as an ice prevention means, rather than as a deicer, because fast forming ice which is not immediately recognized by the pilot may significantly lower the amount of heat available from the carburetor heating system..."