NTSB Factual Report

HISTORY OF FLIGHT

On September 26, 1998, at 1637 central daylight time, a Cessna 170B single-engine airplane, N3469D, owned and operated by the pilot, was substantially damaged during terrain impact following collision with a power line near Weatherford, Texas. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations (CFR) Part 91 personal cross-country flight. The non-instrument rated private pilot and his sole passenger were fatally injured. The flight originated from Stamford, Texas, at 1530. The flight's destination was the pilot's private airstrip located about 3.5 nautical miles north of Weatherford.

A witness reported to the NTSB investigator-in-charge that while he was target practicing at a firing range located near the accident site, he heard the aircraft fly overhead several times. He went outside to watch the airplane and observed the airplane flying from south to north at about the same level as the power lines. As the airplane approached the unmarked wires, its nose pitched up without the pilot adding power, struck the top static wire, and subsequently impacted the ground. The witness further reported that the engine sounded "great."

PERSONNEL INFORMATION

The 79-year-old pilot's flight logbook was not located; therefore, total flight time could not be determined. His last biennial flight review was completed on February 15, 1998. According to FAA records, the pilot was issued a Private Pilot Certificate on May 29, 1996. According to the application for the pilot's most recent third class medical certificate, dated January 20, 1997, he had accumulated a total of 4,000 flight hours, of which 50 hours were in the previous six months.

AIRCRAFT INFORMATION

The 1955 Cessna model 170B, serial number 27012, was equipped with a 145-horsepower Continental O-300-A engine. Maintenance records revealed that the engine was last overhauled on January 9, 1990, at a total engine time of 4,435.0 hours. According to maintenance records, the last annual inspection was completed on January 22, 1998, at 3,336.98 hours. A review of the airframe and engine records by the NTSB investigator-in-charge did not reveal evidence of any anomalies or uncorrected maintenance defects.

AERODROME INFORMATION

The pilot's private airstrip has a single 1,800 foot long grass runway oriented north-south. There are east-west oriented power lines located about 300 yards north of the runway. According to local residents, the pilot would normally takeoff to the south and land to the north.

WRECKAGE IMPACT INFORMATION

Examination of the accident site revealed that the aircraft came to rest inverted in the initial ground scar, on a measured magnetic heading of 038 degrees, about 179 feet north of the power lines. The front of the airplane from the firewall forward was displaced upward and to the right. The outboard section of the left wing was displaced downward and aft, and the right wing was displaced upward and aft. The cabin roof had a more pronounced downward crushing on the left side then the right, and the fuselage was buckled just aft of the cabin area. Continuity was established to all flight controls.

The left main landing gear tire had a straight-line abrasion across the tire tread extending around the inside edge of the tire. The left lower strut/axle had scrape marks on the leading edge from the brake hose clamp down to the wheel attachment bolts. The right main landing gear tire also had a straight-line abrasion across the tire tread extending around the outside edge of the tire.

Examination of the engine revealed that the propeller flange was partially separated from the crankshaft. One propeller blade exhibited twisting and was bent aft with the outboard six inches separated. This separated tip was curled forward. The other blade exhibited "S" bending. Continuity was confirmed to all cylinders and to the rear of the engine. Finger compression was established to all cylinders except #6. The #6 cylinder sustained impact damage. Both magnetos sparked at all terminals when rotated by hand.

The aircraft was not equipped with shoulder harnesses.

MEDICAL AND PATHOLOGICAL INFORMATION

The autopsy was performed by the Office of Medical Examiner, Tarrant County, Texas. There was no evidence found of any preexisting disease that could have contributed to the accident.

Toxicology analysis performed by the Civil Aeromedical Institute (CAMI), Oklahoma City, Oklahoma, was negative for drugs and alcohol.

ADDITIONAL DATA

According to TU Electric, the airplane contacted the southern static line, which spanned between tower number 54/4 (west) and tower number 54/5 (east). Although TU Electric could not tell with certainty, "it is believed that the plane made contact with the southern static line approximately 341.6 feet to the west from the western fence line of Jupiter Road." The height of the northern static wire at the approximate mid-span point was 95.2 agl. The height of the newly installed southern static wire at the approximate mid-span point is approximately 95.9 feet agl. There was no reported interruption of power.

The airplane was released to the owner's representative on September 27, 1998.

NTSB Probable Cause

The pilot's failure to maintain obstacle clearance.