ERA12LA279

While completing a cross-country flight, with the airplane over a seacoast and descending to pattern altitude, the pilot reduced power. The engine "hesitated" a couple of times, so the pilot increased power and applied full rich mixture. As the engine "caught" and accelerated, the pilot applied carburetor heat. He then leveled the wings and looked at the wing root fuel sight gauges to confirm that the airplane had fuel. At the same time, the engine again began to run rough. The pilot rocked the wings to ensure that there was no air lock in the fuel lines and confirmed that the magnetos were on and the primer was in; however, the engine lost total power, the propeller stopped completely, and the airplane descended into a tree. The airplane was subsequently removed from the tree, fuel was confirmed onboard, and no preexisting mechanical anomalies were noted. The airplane's wings were then removed for its transport to a storage facility. At the facility, an auxiliary fuel tank was placed on top of the cabin, with fuel flow directly to the carburetor. After several attempts, the engine was started, and it eventually ran at all power settings. A carburetor icing probability chart revealed that, at the ambient temperature and dew point at the time of the accident, conditions favored carburetor icing at glide and cruise power. It is likely that, if the pilot had applied carburetor heat before his initial power reduction, it would have prevented the formation of carburetor ice and avoided the loss of engine power.

On April 13, 2012, about 1115 eastern daylight time, an experimental amateur-built Murphy Rebel, N24V, was substantially damaged when it impacted trees during a forced landing while approaching Falmouth Airpark (5B6), Falmouth, Massachusetts. The certificated private pilot sustained minor injuries. Visual meteorological conditions prevailed. No flight plan had been filed for the flight, between Fitchburg Municipal Airport (FIT), Fitchburg, Massachusetts, and Falmouth. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. According to the pilot, the airplane was about 1 ½ miles from the airport, over the seacoast and descending to pattern altitude, when the pilot reduced power. The engine "hesitated" a couple of times, so the pilot increased power and applied full rich mixture. As the engine "caught" and accelerated, the pilot applied carburetor heat. He then leveled the wings and looked at the wing root fuel sight gauges to confirm that the airplane had fuel. At the same time, the engine began to run roughly again. The pilot then rocked the wings to ensure that there was no air lock in the fuel lines, and confirmed that the magnetos were on and the primer was in. He then turned the airplane toward the runway 7 traffic pattern, and the engine and propeller stopped completely. The pilot configured the airplane for its best glide airspeed. However, he realized that the airplane would not make it to the airport, so he switched off the magnetos and all circuit breakers, and moved the carburetor heat, throttle and mixture controls forward. The pilot then radioed that the airplane was descending into trees, and just before impact, flared it "hard" so the airplane would "mush" into them. As it impacted a 15- to 18-foot tree, the airplane tipped about 70 degrees to the right, and the right wingtip came to rest against the ground. The pilot noted fuel leaking from the wing tanks, exited the airplane on the up-wing side, and climbed down the tree. The responding Federal Aviation Administration (FAA) inspector confirmed that fuel did leak from the airplane, and that he found fuel in the gascolater and carburetor. He also confirmed crankshaft continuity and cylinder compression, and noted that the spark plugs, with the exception of the lower No. 1 and No. 3, which were covered in oil, appeared "normal." The pilot stated to the inspector that he had flown round trip from 5B6 to FIT with winds accounting for a 1-hour, 10-minute flight outbound and a 35-minute flight during the return. He further stated that the airplane had 22 gallons fuel at initial departure, and that when the engine lost power, he saw that the fuel gauges indicated about 4 gallons in each tank. After the airplane's recovery from the tree, the wings were removed and the airplane was transported to an aviation storage facility in Clayton, Delaware. On May 3, 2012, with NTSB oversight, an auxiliary fuel container was placed on top of the airplane'scabin, then connected to the fuel line that led directly to the carburetor. After several attempts, the engine was started, and although it initially lost power at low power settings, it eventually ran at all power settings. Weather, recorded at 1115, at an airport 3 nautical miles to the north, included winds from 010 degrees true at 5, gusting to 14 knots, clear skies, temperature 12 degrees C, and dew point -4 degrees C. An FAA carburetor icing probability chart revealed that, at the recorded ambient temperature and dew point, conditions favored carburetor icing at glide and cruise power.