NTSB Factual Report

HISTORY OF FLIGHT

On May 7, 2005, at 0605 Pacific daylight time, N42LC, a Champion 7ECA, landed in a soccer field about 5 miles south of the San Luis Obispo Airport, San Luis Obispo, California, and collided with a power pole. The private pilot/owner was operating the airplane under the provisions of 14 CFR Part 91. The pilot was the sole occupant and sustained minor injuries; the airplane was substantially damaged. The airplane departed from the San Luis Obispo Airport at 0555 for the local area flight. Visual meteorological conditions prevailed and no flight plan had been filed.

Witnesses reported to the California Polytechnic State University Police seeing and hearing the airplane flying overhead of the university soccer field and rodeo unit. The plane flew low heading east and eventually landing in the soccer field. After it landed it wobbled and skidded on the field until it was out of sight, at which time they heard a loud crash and saw a blue flash of light in the sky towards the southeast side of the fields. When they arrived on scene a strong smell of fuel filled the air and they observed fuel leaking from the left wing. They unbuckled the pilot from the seat and removed him from the cockpit. The pilot was confused and disoriented, and could not remember what had happened.

According to the responding rescue personnel, the pilot landed the airplane in a soccer field and collided with a power pole at the end of the field. The left forward side of the airplane was lodged around a power pole. The pilot could not recall the circumstances of the accident following the event. Witnesses indicated that the airplane was circling the soccer field with a sputtering engine, prior to the landing.

The Federal Aviation Administration (FAA) inspector responded to the accident scene. Documents in the airplane indicated that the airplane was last fueled on May 1, 2005, with the addition of 20 gallons of fuel at a tachometer reading of 1,375.92. On May 6, the pilot annotated that the tachometer time was 1,376.15 and that no fuel had been added to the airplane. A small amount of fuel covered the bottom of the right wing; the inspector was unable to visually examine the left wing tank due to the condition of the wreckage. The inspector verified that the outer portion of the vent tube on the wing was clear and free from obstruction. A sample of fuel was drained from the wing. The smell and color of the fuel was consistent with 87 octane automotive gas.

According to personnel that recovered the airplane, approximately 1/2-gallon of fuel total was drained from the airplane.

PERSONNEL INFORMATION

A review of FAA airman records revealed that the pilot held a private pilot certificate dated November 9, 1998, with a single engine land (SEL) rating. The pilot reported in the National Transportation Safety Board pilot/operator accident report that he had 780 hours of total flight time and 580 hours in this make and model of airplane. He had flown 20 hours in the last 30 days. His last biennial flight review was on November 15, 2004. The pilot held a third-class medical certificate dated July 1, 2004, with the limitation that the pilot wear corrective lenses.

AIRCRAFT INFORMATION

The airplane was a single engine, two-place tandem seated, high-wing airplane, with two main landing gear struts and a tail wheel. The pilot reported that the last annual inspection was performed on January 1, 2005, and there was a total of 3,350 hours on the airframe. The engine was a Lycoming O-320-C1, serial number, L-8974-15, with 750 hours since maintenance overhaul (TSMO).

METEOROLOGICAL INFORMATION

The closest weather observation station was the San Luis Obispo airport, which was within 10 miles of the accident site. At the time of the accident the station was reporting a temperature and dew point of 8 and 7 degrees Celsius, respectively. Review of a carburetor icing probability chart disclosed that the reported temperature and dew point were in the center of the area for serious icing at any power setting.

TEST AND RESEARCH

The airframe and engine were examined by the Safety Board investigator-in-charge (IIC) and a technical representative from Lycoming. The airplane was examined with the wings and horizontal stabilizer removed. The tachometer in the cockpit read 1376.27.

The engine remained fastened to the airframe engine mounts and was slung from a hoist. All four cylinders were present on the engine case and the induction and exhaust system appeared undamaged. Throttle and mixture control continuity was established between the control levers in the cockpit and the carburetor. The controls were easily manipulated from the cockpit and responded correctly on the throttle and mixture lever arms on the carburetor. The carburetor heat was observed on the airbox to be in the cold configuration. The upper four spark plugs, REM 38E's, were removed. The spark plugs were all grey in color with similar wear patterns between them, and exhibited no mechanical damage. Thumb compression was achieved on all four cylinders in firing order. The cylinders were examined using a borescope, which revealed wear consistent with normal operation. The magneto timing was measured at exactly 25 degrees advanced on both magnetos. Electrical continuity was established between the ignition switches, p-leads, and magnetos. Five quarts of oil was measured on the oil dipstick. The gascolator bowl was observed dislodged from its mounting base and the gasket ripped. The bowl contained brownish liquid varnish and the filter screen was clear and free from debris.

A remote external fuel tank was plumed into the right wing fuel line and secured to the upper surface of the fuselage behind the cockpit. The gascolater gasket was replaced and the bowl was placed in service. The external fuel tank was filled with 100LL aviation gasoline. The fuel valve was opened in the cockpit and fuel flow was verified by allowing fuel to flow through the gascolator drain valve until the flow was steady and clear. The engine and fuel system was examined for leaks; none were noted. A battery was connected to the battery leads and the engine was cranked successfully using the starter. The engine was then started using normal starting procedures and ran up to 1,700 rpm. Oil pressure was observed in the normal range, about 70psi, and the engine was allowed to reach normal operating temperature. The magnetos were checked, each producing a 25-rpm reduction when cycled. The throttle was advanced to 1,900 rpm and ran for about 4 minutes. The throttle was then reduced to idle, approximately 800 rpm, and advanced to 1,900 rpm three times producing a smooth power change each time. The engine was brought back to 800 rpm (idle) and shut down using the idle cut off, which produced a rise of about 50 rpm just before engine cut out. The post accident engine run inspection revealed no fuel or oil leaks.

NTSB Probable Cause

a loss of engine power due to carburetor icing and the pilot's failure to use carburetor heat.