Accident Details
On April 4, 2013, at 0840 eastern daylight time, a Cessna 152, registration N6141Q, was substantially damaged during a forced landing following a partial loss of engine power near Miami, Florida. The flight instructor and student pilot were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local instructional flight, which originated from Kendall-Tamiami Executive Airport (TMB) at 0745. The flight was conducted under 14 CFR Part 91.
Engine Failure
At the conclusion of an uneventful training flight, the instructor asked the student to demonstrate a steep turn. During the turn, the engine experienced a partial loss of power, and the propeller continued to windmill. The instructor took control, returned to straight-and-level flight, and attempted to restore power. After determining that power could not be restored and that the airplane could not reach TMB, the instructor executed a forced landing to a road. During the landing, the left main landing gear contacted a grassy area, causing the nose to yaw left. The airplane then struck a bush, resulting in substantial damage to the right wing.
Post-accident examination of the engine, supervised by an FAA inspector, revealed that the exhaust valve head of the number 3 cylinder had fractured and separated from the valve stem. The valve head was recovered and showed evidence of post-separation damage and contact with the cylinder and piston dome. No other mechanical deficiencies were found.
Maintenance History
The aircraft, manufactured in 1981, was equipped with a Lycoming O-235-L2C engine. Maintenance logs indicated that the engine was installed after a field overhaul in June 1985 with 1,994 total hours. In December 1985, after 299 hours since overhaul, inspection of the number 3 cylinder revealed a broken rocker shaft boss, and “serviceable valves” were installed. No subsequent replacement of the number 3 cylinder or its valves was noted between 1985 and the accident. The prior service history of the installed valves could not be determined.
Maintenance records between 1985 and 2011 were not available. An entry from October 2011 noted 1,876 total hours since the most recent overhaul. The most recent annual inspection was completed on April 14, 2012, with 1,929 hours since overhaul. The most recent 100-hour inspection occurred on March 26, 2013, at 2,408 hours since overhaul. At the time of the accident, the engine had accumulated 2,495 hours since the most recent overhaul and 6,269 hours since manufacture. Lycoming Service Instruction 1009AS, revised May 25, 2006, recommended an overhaul interval of 2,400 hours or 12 calendar years for the O-235 engine.