Accident Description
On July 3, 2014, at approximately 1100 central daylight time, a Piper PA-24-250, registration N5923P, was substantially damaged during an aborted landing at Monroe County Airport (MVC) in Monroeville, Alabama. The flight instructor and a pilot-rated passenger sustained minor injuries. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the personal flight conducted under 14 CFR Part 91. The flight had originated from Shelby County Airport (EET) in Alabaster, Alabama at 1000.
Pilot and Witness Accounts
According to the flight instructor's written statement, he performed three landings at EET for currency and then departed for MVC with another pilot. Upon arrival, the instructor configured the airplane for an RNAV/GPS approach to runway 03. At about 100 feet above ground level (agl), he initiated a go-around and retracted the landing gear and flaps. When the airplane reached approximately 400 ft agl, the engine sputtered, went quiet, briefly regained power, and then went quiet again. The instructor switched fuel tanks, confirmed the fuel boost pump was on, observed the mixture was rich and both magnetos were on, established best glide speed, and selected a field to the right for a forced landing. During the landing, the airplane struck a tree, the left wing separated, and the airplane came to rest inverted, causing substantial damage to both wings and the fuselage.
A witness reported that the engine began sputtering as the airplane climbed away from the runway at about 100 ft agl, approximately 800 ft from the departure end of runway 03. The airplane then entered level flight and the sputtering stopped. The witness heard the engine running, but not at full power. The airplane climbed about 100 ft, made a right turn, and descended until out of view.
In a follow-up interview, the instructor stated the flight's purpose was to familiarize the pilot-rated passenger with the newly-installed GPS. Before departure, he visually inspected both wing tanks, estimating about 30 gallons each. After engine start, the airplane idled for about 30 minutes while configuring the GPS. They completed three takeoffs and landings at EET before departing for MVC, with a total flight time of 1 hour and 20 minutes on the left fuel tank. The instructor noted that he did not apply carburetor heat after the engine power loss.
Post-Accident Examination
A Federal Aviation Administration inspector examined the airplane and engine, finding no mechanical malfunctions that would have caused a loss of engine power. The crankshaft rotated by hand established continuity through the powertrain, valvetrain, and accessory section. Compression was present on all cylinders, and magnetos produced spark at all terminal leads. Fuel line continuity from the bladder tanks to the carburetor was clear of contamination. The fuel strainer was free of debris, and the carburetor screen had minor debris but was not plugged. The carburetor separated from the engine during impact; floats were normal, and the needle and seat had no restrictions. Some rust and debris in the carburetor fuel bowl likely accumulated during postaccident storage. Both fuel boost pumps produced suction when connected to a 12-volt battery.
Weather and Carburetor Icing Potential
A weather observation at Middleton Field Airport (GZH), Evergreen, Alabama, about 16 nautical miles east of the accident site, reported wind from 350 degrees at 3 knots, visibility 10 statute miles, clear sky, temperature 27°C, dewpoint 22°C, altimeter 30.08 inches of mercury. According to the manufacturer's pilot's operating handbook, at 6,000 feet cruise altitude with standard conditions and about 2,200 rpm, estimated fuel consumption was approximately 14 gallons per hour. Based on 1 hour 36 minutes of flight time, the engine burned about 22.4 gallons. A review of an FAA carburetor icing envelope chart indicated a potential for serious icing at descent power given the atmospheric conditions.