History of Flight
On April 29, 2013, at approximately 1401 Pacific daylight time, a midair collision occurred between a Cessna 172RG (registration N4677V) and a Cessna 172M (registration N64030) about 3 miles southwest of Calabasas, California. The 172RG was operated by American Flyers as an instructional flight under 14 CFR Part 91, with a certified flight instructor (CFI) and two pilot-rated students on board. The 172M was operated by its commercial pilot as a personal flight under Part 91, with a private pilot also on board.
The 172M departed Santa Monica Municipal Airport (SMO) at about 1313, and the 172RG departed SMO at about 1353. Visual meteorological conditions prevailed, and no flight plans were filed.
The CFI of the 172RG reported that after departure, they flew north along the Santa Monica shoreline to the Malibu State Park and Simi Valley practice area. They made position broadcasts on the practice area frequency but received no acknowledgments. The pilot under instruction performed clearing turns, and after leveling off at 3,500 feet, the CFI heard a loud bang and felt an impact on the left side. The left wing leading edge was damaged, the pitot tube was missing, the left wing strut was bent, and the pilot's side window was broken. The CFI executed a forced gear-up landing on a golf course; the airplane slid about 430 feet, struck a tree, and came to rest.
A witness reported hearing an extremely loud strike, then observed an airplane descending almost vertically. The witness's wife saw a second airplane depart to the west.
Radar data showed the 172RG at 3,500 feet mean sea level (msl) at 14:01:04, making a gradual right turn. At 14:01:55, the collision occurred at 3,400 feet msl. The 172M was observed at 3,200 feet msl at 13:58:23, making a gradual left turn. Radar data indicated the collision occurred at 14:01:55. After the collision, the 172RG continued flying, while the 172M made a sharp left turn and descended rapidly.
Personnel Information
The CFI of the 172RG, aged 37, held an airline transport pilot certificate and a flight instructor certificate, with 2,200 total flight hours, 600 in the accident make and model. The pilot under instruction (right seat) was a 34-year-old commercial pilot with 485 total hours, on his first flight in the 172RG type.
The 172M's commercial pilot, aged 69, held a commercial pilot certificate and a flight instructor certificate, with 1,750 total hours reported at her last medical examination. The private pilot, aged 63, held a private pilot certificate and an airframe and powerplant mechanic certificate, with 1,350 total hours reported.
Aircraft Information
The Cessna 172RG, serial number 172RG0224, was a four-seat, high-wing airplane powered by a Lycoming O-360 engine. It was white with blue striping and had a 100-hour inspection on April 5, 2013, at an airframe total time of 10,383 hours.
The Cessna 172M, serial number 17264976, was a four-seat, high-wing airplane powered by a Lycoming O-320 engine. It was white with red and blue striping. On April 16, 2013, the engine and propeller were reinstalled following a previous propeller strike, and an annual inspection was performed.
Meteorological Information
The nearest weather reporting station, Van Nuys Airport (VNY), about 9 nautical miles northeast, reported at 1351: clear skies, wind from 140 degrees at 6 knots, visibility 10 statute miles, temperature 17°C, dew point 11°C, altimeter 29.82 inches of mercury.
Wreckage and Impact Information
The 172RG landed on a golf course, sliding about 430 feet before striking a tree. The left wing leading edge had two large dents with paint transfer marks. Parts of the 172M's right horizontal stabilizer and elevator were found near the 172RG's left horizontal stabilizer.
The 172M impacted terrain in a nose-low attitude at an elevation of 1,170 feet, and a post-impact fire consumed the wreckage. The right horizontal stabilizer and elevator were separated; the missing components were found with the 172RG. Engine examination revealed thermal damage but no internal catastrophic failure.
Communications
FAA records indicate the 172M pilot contacted SMO tower at 1313 requesting pattern work after maintenance, then at 1340 requested departure to the west. The 172RG pilot requested departure to the west at 1353. No communication between the two aircraft was recorded.
Medical and Pathological Information
Autopsies of the 172M pilots, conducted by the Los Angeles County Department of Coroner, concluded the cause of death for each was multiple traumatic injuries. Toxicological tests were negative for ethanol and drugs; carbon monoxide and cyanide tests were not performed.
Tests and Research
Paint transfer marks on the 172RG wing root and the 172M horizontal stabilizer, along with radar data, indicated the airplanes converged at about a 50-degree angle relative to their longitudinal axes. The 172RG was traveling at about 102 knots, the 172M at about 101 knots, resulting in a horizontal collision angle of about 80 degrees.