Accident Details
Probable Cause and Findings
The loss of engine power due to carburetor ice resulting from the flight instructor's failure to use the carburetor heat when simulating an engine failure. Contributing to the accident were the carburetor icing weather condition and the lack of suitable terrain for the forced landing.
Aircraft Information
Registered Owner (Historical)
Analysis
On June 26, 2008, about 1630 Pacific daylight time, a Cessna 172N, N6360D, experienced a loss of engine power and made a forced landing near El Cajon, California. California Flight Academy was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as an instructional flight. The certified flight instructor (CFI) and the student pilot were not injured; the airplane sustained substantial damage. The flight departed Gillespie Field Airport, El Cajon, about 1530, on a local instructional flight. Visual meteorological conditions prevailed, and no flight plan had been filed.
According to the CFI, while over San Vicente Reservoir, he simulated an engine failure by retarding the throttle. After "1 minute of procedures," the CFI applied power but the engine did not respond. The CFI performed a forced landing to a field on a ranch. During landing, the left wing tip struck the ground, and the left wing sustained structural damage.
A Federal Aviation Administration (FAA) inspector examined the airplane at the accident site. The inspector observed fuel in both tanks and in the gascolator. The engine oil level was at 7 quarts, and the air filter was not obstructed. The wings were removed and the airplane was recovered to the operator's hangar at Gillespie Field. On July 10, 2008, an FAA inspector observed a test run of the engine. Fuel was supplied to the engine by means of a line leading from a bucket directly to the gascolator. The engine started and idled normally. Power was increased to 1800 rpm, and the carburetor heat was applied and found to operate normally. Power was further increased to 2000 rpm and the engine was then shutdown by moving the mixture control to the idle cutoff position.
The temperature and dew point at Gillespie Field at 1647 were recorded as 75 degrees Fahrenheit and 55 degrees Fahrenheit, respectively. Plotting these values on a carburetor icing probability chart indicated that the airplane was operating in the range for serious icing at glide power. According to the operator, the CFI did not apply carburetor heat prior to retarding the throttle during the simulated engine failure.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# LAX08LA206