NTSB Factual Report

HISTORY OF FLIGHT

On October 1, 1994, at 2208 Pacific daylight time, a Cessna 170B, N170CT, was destroyed when it crashed at Ramona, California. The aircraft was jointly owned and operated by the pilot and was on a solo cross-country flight to Gillespie Field. Instrument meteorological conditions prevailed at the time and no flight plan had been filed. The flight originated from the Ramona airport at 2205 on the night of the accident.

A witness reported that the pilot departed Ramona airport on runway 27, making a left turn after climbing several hundred feet. The witness stated that she lost visual contact with the aircraft's position lights after the aircraft initiated its left turn. Other witnesses on the ground reported hearing the aircraft flying overhead. Engine sounds were reported until the time of impact. Witnesses also reported that the aircraft sounded to be lower than the 1,000-foot traffic pattern altitude established for the Ramona airport.

The aircraft crashed in an open area approximately 1 1/2 miles southwest from the airport on a final heading of 240 degrees. The wreckage was distributed over a 225-foot area.

PERSONNEL INFORMATION

The pilot's third-class medical certificate had been expired 11 months at the time of the accident. No one who knew the pilot could offer an explanation as to why he had not obtained a current medical certificate.

The latest biennial flight review (BFR) in the pilot's logbook was dated August 5, 1992. One of the aircraft's coowners, who is also a CFI, stated that he remembered giving the pilot a BFR on February 21, 1994, but because the pilot did not have his logbook, the BFR was not logged.

METEOROLOGICAL CONDITIONS

One witness reported that the pilot had obtained a telephone weather briefing prior to departure. A check of Federal Aviation Administration (FAA) flight service facilities records failed to identify a record of the briefing given to the pilot of the accident aircraft. At 2155, the weather at Miramar Naval Air Station, the nearest weather reporting facility, located 17 miles southwest of Ramona, was reported as marginal VFR.

While Ramona does not have a reporting station, two witnesses near the accident site estimated the base of the clouds to be approximately 150 feet agl at the time of the accident and Woodson Mountain was obscured, which is located 3 miles southwest of the airport.

WRECKAGE AND IMPACT INFORMATION

A postcrash examination of the aircraft conducted by the FAA and manufacturers' representatives did not identify any material deficiencies.

A visual inspection of the aircraft revealed the following settings, readings, and control positions. The airspeed indicator read 115 knots. The communication and navigation radios were set to 121.9 and 109.0, respectively. The throttle was full open, the mixture control was full rich, and the propeller control was full increase. The magneto switch was in the "both" position. The exhaust gas temperature gauge read 1,375 degrees. The clock read 8:02. The oil temperature was pegged on the low end stop, just below 100 degrees, and the oil pressure read 25 psi. The primer control was in, but not locked, and the fuel selector handle was on "both." The tachometer had recorded 31.5 hours, while the suction gauge read 2.9 psi.

The engine remained partially attached to the firewall. Both magnetos, oil pressure screen, and vacuum pump remained attached while the carburetor, fuel pump, propeller governor, starter, generator, and propeller had separated from the engine.

The vacuum pump was removed from the engine and inspected. The drive coupler was intact and the pump was rotated by hand. The housing was opened and the vanes were found intact.

The ignition system was inspected and both magnetos produced spark through all terminals during hand rotation of the shaft. Both were equipped with impulse couplers which also functioned during hand rotation.

All spark plugs, except for the bottom No. 1 plug, were removed and examined. These the plugs exhibited normal electrode wear and all, except the top No. 2, were dry. The bottom No. 1 was broken and trapped by the exhaust system and was not removed.

The fuel inlet screen was removed and found free of contamination. The Marvel-Schebler carburetor housings were separated and a composite float was observed. No fuel was found in the carburetor bowl. The fuel pump linkage was broken and separated from the engine, but the pump diaphragm was operated and suction was produced. No fuel was found in the pump.

The oil sump assembly was destroyed by ground impact. The oil suction screen was removed and visually examined. The presence of nonferris metal was observed in the screen along with carbon deposits.

The valve and gear train continuity was established through a 180-degree hand rotation of the crankshaft.

A compression check of the cylinders could not be performed due to a bent propeller flange which prevented full rotation of the crankshaft.

The Hartzell propellers were examined and one blade was found broken with the separated tip section being located in the initial ground scar. Both blades exhibited chordwise scratches and torsional twisting. When the propeller governor was hand rotated, oil pumped out and a sucking sound was heard.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was conducted by the San Diego County Medical Examiner, with specimens retained for toxicological analysis. The toxicological tests were negative for alcohol and all screened drugs.

ADDITIONAL INFORMATION

The aircraft was recovered and secured in a storage facility at the Ramona airport. The wreckage was subsequently released to a representative of the registered owner.

NTSB Probable Cause

the noninstrument-rated pilot's failure to maintain aircraft control due to spatial disorientation after encountering instrument meteorological conditions after the pilot decided to takeoff in adverse weather conditions. A factor in the accident was the dark nighttime lighting conditions and the pilot's lack of recent experience.