Accident Overview
On September 24, 2019, about 1205 eastern daylight time, a Cessna 172K, registration N78192, was substantially damaged when it came to rest in treetops near Manville, New Jersey. The student pilot was not injured. The airplane was being operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.
Flight and Engine Failure
According to the student pilot, he departed with 30 gallons of fuel for a solo cross-country flight. He had calculated a fuel consumption of about 15 gallons for the 187-nautical-mile trip. At the conclusion of the flight, while entering the traffic pattern for landing, the pilot turned from the base leg to final approach. At that point, the engine began to run rough, followed shortly by a total loss of power. The pilot confirmed the fuel selector was on "both," the mixture was rich, and the carburetor heat was on. He turned off the carburetor heat and attempted to restart the engine, but it did not respond and the propeller did not move.
Forced Landing and Wreckage Examination
Determining that the airplane would not reach the runway, the pilot secured the engine and executed a landing into the treetops. After the airplane came to a stop, he observed branches had punctured both wings, with fuel leaking from both sides.
An FAA inspector examined the wreckage. The airplane came to rest upright in the treetops about 70 feet above the ground. After removal, the inspector found little to no fuel remaining in the wing tanks. Fuel was present in the engine fuel drain; a sample was blue in color with no visible water or debris. No holes or other visible damage were noted with the engine.
Engine and Airbox Findings
Examination of the engine revealed two pieces of debris inside the carburetor airbox downstream from the air filter element. The debris was consistent with epoxy or sealant used during repairs of the airbox. The airbox showed signs of having been repaired and patched several times, with some sealant on the repairs appearing loose. When the debris was placed in the carburetor venturi for reference, it blocked about 50 to 75 percent of the opening.