Accident Summary
On June 16, 2012, about 0040 eastern daylight time, a Cessna 152, registration N67324, was substantially damaged after losing engine power and colliding with terrain near Miami, Florida. The airplane was operated by Dean International Flight School under Part 91 as an instructional flight. Both the flight instructor and student pilot were uninjured. Night visual meteorological conditions prevailed, and a visual flight rules flight plan was filed. The flight originated from Fort Myers, Florida (FMY) at about 2300 on June 15, 2012, and was destined for Miami, Florida (TMB).
Flight and Engine Failure
The student pilot was at the controls when, about 7 miles northwest of TMB, the first indication of engine roughness was observed. Carburetor heat was applied, but no improvement was noted. Shortly thereafter, the engine made sputtering sounds and stopped. The flight instructor took control and attempted a restart, which was unsuccessful, leading to a forced landing in a nearby field.
Post-Accident Findings
An airworthiness inspector from the FAA documented the wreckage recovery. Mechanics employed by the operator responded to the accident site. The aircraft was found inverted, with no fuel or oil spill noted. The wing fuel tanks were intact, and the filler caps were secure. After righting the aircraft, about one quart of fuel was drained from each tank. The oil dipstick showed no oil level registering on the stick. There was no evidence of an oil leak on the engine or its components.
During a later inspection at the operator's facilities, the FAA inspector observed no oil or oil residue on the engine firewall, engine, or cowling. The propeller could not be turned. The operator's lead mechanic informed the inspector that the oil temperature line had been removed from the wreckage after the accident and tested on another engine, where it leaked. The FAA inspector noted that the NTSB had not released the wreckage for such testing.
Engine Examination
A disassembled engine examination revealed evidence of seizure. The crankshaft, aft of the number 3 crankpin journal, was twisted counterclockwise and bent. The area around the number 3 crankpin journal was discolored, consistent with elevated temperature and lack of lubrication. Ferrous particles were found in the oil sump. The number 3 connecting rod exhibited heat damage and distortion.
Maintenance Records
According to maintenance records, a 100-hour inspection was performed on June 13, 2012, which included an oil and filter change. The tachometer time at inspection was 3,662.1 hours. At the time of the FAA inspection, the tachometer reading was 3,677.6 hours. The engine manufacturer specifies a minimum safe oil quantity of 2 quarts in the sump.
Regulatory Note
49 CFR Part 830.10 requires aircraft operators to preserve wreckage until the NTSB takes custody or grants release. In this case, the oil temperature line was removed and tested without NTSB authorization.