ANC06LA067 · Cessna 182

The private certificated pilot reported that he was looking for potential landing areas near a cabin on a remote island during a cross-country Title 14, CFR Part 91 personal flight. He scanned an area at 400 feet above ground level (agl) for about 15 to 20 minutes. The airplane was configured with 20 degrees of flaps, carburetor heat on, and an engine power setting of about 18 to 20 inches of manifold pressure. The outside temperature was 52 degrees F. He spotted the cabin he was looking for, and began a descent for a low-level pass along a beach. The pilot configured the airplane to full flaps, the engine power was near idle, and the carburetor heat was "on." He then attempted to add engine power to level the airplane, but it did not respond. He pushed the throttle in and out several times without any change in power from idle. The airplane continued to descend, and as the wheel began to strike low brush, the engine went to full power, but the airplane touched down in the rough terrain and nosed over. The airplane received structural damage to the fuselage and wings. In the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) submitted by the pilot, he indicated that during the flight to the island, the engine developed a slight roughness, accompanied by about a 1 inch drop in manifold pressure. He noted the carburetor temperature gauge was indicating -35 degrees F. He applied carburetor heat, which raised the carburetor heat temperature to about 0 degrees F, but no further. The pilot said he then decreased the engine power to idle, reapplied carburetor heat, and noted that after about 1 minute, the carburetor temperature increased to about 55 degrees F, which resolved the engine roughness. The pilot reported that he previously had a carburetor heat problem about 8 months prior to the accident. After a normal landing at an airport, he applied engine power to takeoff, but the engine would only produce about 14 inches of manifold pressure with the carburetor heat on. After several seconds of idling the engine with full carburetor heat applied, full power was restored. The pilot indicated that the airplane had an annual inspection in February, 2006, and he had flown the airplane for about 120 hours without a repeat of the problem. The airplane was recovered from the island, but the engine was not examined by FAA or NTSB personnel.

Verbatim NTSB analysis and probable cause from the NTSB dataset