NTSB Factual Report

HISTORY OF FLIGHT

On September 25, 1997, about 1735 hours Pacific daylight time, a Cessna 172K, N84621, en route to Boulder City, Nevada, collided with mountainous terrain near Sandy Valley, Nevada. The aircraft was destroyed and the pilot, the sole occupant, received fatal injuries. The aircraft was operated as a personal flight by the pilot/owner when the accident occurred. The flight originated from the Sky Ranch airport in Sandy Valley about 1700. Instrument meteorological conditions prevailed and no flight plan was filed.

According to a witness, a retired airline pilot, the pilot landed at Sky Ranch airport about 1500. He described the weather at the time as approximately 600-foot runway visual range (RVR), with calm winds and heavy rain. He said that from his position on the airport, the sky to the south appeared to be completely obscured. He asked the pilot over the CTAF/UNICOM frequency if he needed fuel, but he replied that he did not require servicing.

The witness, who heard the pilot's side of a telephone conversation, said he told the other party that he was down for weather. When the witness asked the pilot how he found Sky Ranch, he said he was using a handheld GPS receiver, and that he had been "skud-running" all the way from Reno, Nevada. He said he had made a stop due to bad weather in Furnace Creek, California. He asked the pilot if he was instrument rated and the pilot replied that he was rated, but that he was not current.

After 2 hours on the ground, the rain stopped and the witness estimated the clouds to the north were now about 1,000 feet with 1 mile visibility. The sky to the south, however, was still obscured with no lateral visibility. At 1700, the pilot decided to takeoff and said he was going to try flying north to a private airport in Pahrump, Nevada. The pilot did not call for a weather briefing before he departed.

After he departed, the witness kept in contact with the pilot over the CTAF/UNICOM frequency and heard him say that he estimated the ceiling was about 7,000 feet and the sky was getting lighter. About 5 minutes later, the pilot said he had Pahrump airport in sight and was descending on approach. There were several other subsequent transmissions; however, due to poor transmission quality, the witness was not able to understand what was being said. The Pahrump airport is about 33 miles northwest of the Sky Ranch airport.

The aircraft was found by members of the Civil Air Patrol on October 4, 1997, about 9 miles southeast of the Sky Ranch airport. During the initial recovery, an emergency response helicopter airlifted rescue personnel to the accident site. During the response, the aircraft slid about 200 feet down the face of the south slope as the helicopter hovered overhead.

PILOT INFORMATION

The pilot's logbook contained an endorsement for a satisfactory instrument currency check that was conducted on October 3, 1996. The flight check was performed in the accident aircraft. The logbook also reflected 16 day VFR takeoffs and landings in the preceding 90 days. His last logged instrument flight, conducted under actual conditions, was on June 6, 1997. The flight was for a period of 3.9 hours and included four instrument approaches. The last logged entry was on August 19, 1997, for a day VFR flight in a Pitts S-1C for a period of .5 hours.

AIRCRAFT INFORMATION

According to the delivery documents provided by the manufacturer, the aircraft was equipped for IFR flight. The aircraft was also equipped with a two axis (roll and yaw) autopilot. The autopilot was found in the heading mode, and the course selector was set on 161 degrees.

The pilot reported to the witness that he refueled in Bishop, California. Fuel records show the pilot purchased 17.7 gallons of AV gas on September 25, 1997.

METEOROLOGY

There were no requests for weather services reported for the accident aircraft's registration number.

AIDS TO NAVIGATION

There were no reports of navigation services being requested or provided for the accident aircraft's registration number. The off-route obstruction clearance altitude for the quadrangle containing the accident site is 8,800 feet. The minimum en route altitude for the segment of V394, 5 statute miles northwest of the accident site, is 12,000 feet msl. The minimum obstruction clearance altitude for the same segment is 9,500 feet msl.

A current San Francisco sectional chart was found in the vicinity of the accident site.

A handheld GPS was found in the aircraft wreckage.

COMMUNICATIONS

After departure, there were no reports of air-to-ground communications between the pilot and any ATC facilities.

WRECKAGE AND IMPACT INFORMATION

The aircraft was found on the south side of an east-west ridge. The elevation of the accident site was estimated to be about 3,900 feet msl.

All load bearing components of the airframe were located at the accident site. The leading edges of both main wings exhibited crushing. The empennage was scorpioned to the 3 o'clock position. The control cables were separated along with tearing and crushing of the supporting airframe structure; however, the extent of the damage prevented verification of control continuity to all surfaces.

The propeller remained attached to the propeller flange. One blade was separated at midspan, and the separated portion was recovered at the accident site. The remaining blade exhibited a corkscrew twist. The leading edges of both blades exhibited a series of gouges starting near the hub and extending to the tips. Both blades displayed chordwise scarring.

The engine exhibited impact damage on the left side. The top portion of the No. 2 and 4 cylinders were missing. The No. 1 rocker shaft boss was fractured.

The accessory section housing was removed and the accessory gears were found intact. There was no evidence of valve and piston contact. The crankshaft and connecting rods were undamaged and intact. The camshaft and tappets were also undamaged and intact. Mechanical continuity was established throughout the rotating components.

The aircraft was equipped with right and left magnetos. Both magnetos were damaged, and therefore, engine timing was not determined. The right magneto body remained mounted to the engine and the drive remained safetied and intact.

The carburetor was removed from the engine and examined. The throttle control remained attached to the carburetor. The mixture cable was found disconnected at the arm. The one-piece venturi was in place and there was no evidence of obstructions in the throat. The carburetor was equipped with metal floats. They were intact and moved freely about the pontoon arm. There was no evidence of the floats rubbing against the bowl. There was no residual fuel present.

The No. 3 and No. 4 bottom spark plugs displayed impact damage. The No. 4 top spark plug was missing and was not located. According to the Champion Spark Plugs Check-A-Plug chart AV-27, the plugs displayed coloration consistent with normal operation.

The ignition harness was destroyed and was not tested for continuity.

The alternator was destroyed.

The vacuum pump body was attached to the engine pad. The rotating components were missing from the pump. The pump drive was removed and was found intact.

The oil cooler and oil pressure screen/filter were destroyed. There was no evidence of visible contamination.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was conducted by the Clark County Coroner's Office. According to the report, no potentially impairing or incapacitating preimpact pathological conditions were identified.

Toxicological samples were retained for examination at the Federal Aviation Administration (FAA) Civil Aero Medical Institute, Oklahoma City, Oklahoma. The results were negative for all screened drugs. Positive volatile findings (ethanol, n-butanol, acetaldehyde and isobutanol) in tissue samples were considered by the Safety Board flight surgeon to be the products of putrefaction.

SURVIVAL ASPECTS

The pilot's seat was separated from the seat track. The pilot's lap belt buckle was fasted.

TESTS AND RESEARCH

The GPS receiver was returned to the manufacturer for data retrieval. The data provided an azimuth of the last 32 minutes 51 seconds of the flight in 8-second increments. The last position recorded was 35 degrees 42.50 minutes north latitude, and 115 degrees 29.02 minutes west longitude. A representation of the ground track is appended to this report. A tabular display of the data, point-to-point average ground speeds, and an overlay on an aeronautical sectional chart is also provided (copyrights HTI, Inc. 1995 and E.R.M., Inc. 1996).

According to FAA quality assurance personnel, examination of recorded radar data disclosed no primary or 1200 transponder codes originating from the Sky Ranch airport at the approximate reported time of departure.

ADDTIONAL INFORMATION

The aircraft wreckage was released to a representative of the registered owner on June 5, 1998.

An ELT signal was not detected prior to the discovery of the aircraft wreckage. However, after the aircraft slid down the face of the slope, the emergency response aircraft began receiving an emergency transmitter signal on guard frequency.

NTSB Probable Cause

the pilot's intentional VFR flight into adverse weather conditions, and his failure to maintain sufficient altitude or clearance from mountainous/hilly terrain. Related factors were: the high/mountainous/hilly terrain, and the adverse weather condition (low ceiling).