NTSB Factual Report

On July 4, 1997, at 2100 eastern daylight time, a Cessna 170B, N2416D, piloted by a commercial pilot, was destroyed during a collision with two overhead ground wires of an electrical power transmission lines, the ground and post-impact fire. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot and passenger were fatally injured. The flight departed from Interlochen, Michigan, exact time unknown.

One witness, located about 3/4-mile from the accident site, reported seeing the airplane flying between 150 and 300 feet above the ground. This witness said he heard the engine "...sputtering and running roughly, ... making [an] erratic noise until the point that it disappeared," according to the Grand Traverse County Sheriff s Department report. Another witness said she saw "...the airplane, come in low over my house, just above the trees. The airplane made a second pass, [and] on the third pass... the airplane pulled straight up, recovered to level flight and departed... ."

Two other witnesses said they saw the airplane flying in their area. One said she saw the airplane "...doing... spins." She said the airplane did a "...spin and leveled off at tree top level... ." The third witness said, "...as the airplane passed across the front of [his] house he would estimate [the airplane s] height to be well under a 100 feet." He said the engine was "...not sputtering, but appeared to be functioning properly... ."

Based on a Wolverine Power Supply Company of Cadillac, Michigan, statement, N2416D struck the overhead ground wires about 87 feet above the road where its wreckage was located. According to the Federal Aviation Administration s (FAA) Principal Maintenance Inspector's (PMI) report, two electrical ground wires "...were entangled in the wreckage forward of the main landing gear." The PMI said marks that matched the cable strands were observed on the right landing gear leg.

Flight control continuity was established for all three control surfaces. The engine was fire damaged according to the PMI. He said the carburetor heat control was in the COLD position. The throttle arm was in the mid-travel position, and the mixture was full RICH position according to the PMI. He said the magnetos, fuel pump, oil screen housing, and vacuum pump were "...melted beyond recognition." One propeller blade was bent aft about 15 degrees, according to the PMI. He did not observed rotational marks or leading edge gouges on the propeller's leading edges. The engine crankshaft and camshaft rotated when the engine's crankshaft flange was rotated by hand. Three of the four cylinders had thumb compression. Number four cylinder did not have compression because the rocker arms were not releasing the valves. When the remains of the accessory case were removed from the engine, engine oil spilled on the ground.

A copy of the pilot's logbook was forwarded by the pilot's family. Examination of the logbook revealed he had 486.8 hours logged. Of this flight time, the logbook showed he had 9.9 hours in the Cessna 170 airplane. The logbook showed the pilot's last flight in any airplane was on August 6, 1995. This flight was in the accident airplane. The pilot had received a Flight Review, according to the entry. One page of the logbook showed the pilot had received a Flight Review on July 14, 1995, and another one on August 6, 1995. There were no other logbook entries beyond the August 6, 1995, date.

The pilot's toxicological examination was conducted by the FAA's Civil Aeromedical Institute in Oklahoma City, Oklahoma. The toxicological report showed the pilot had 141.000 (mg/dL, mg/hg) of Ethanol detected in the blood. The report also showed 163.000 (mg/dL, mg/hg) of Ethanol detected in the vitreous fluid and "0.002 ug/mL Tetrahydrocannabinol Carboxylic Acid (Marihuana) was detected in Blood." The pilot's autopsy was conducted by Dr. Stephan D. Cohle at the Blodgett Memorial Medical Center on July 8, 1997.

NTSB Probable Cause

the pilot's impairment of judgment and performance due to alcohol, his resultant improper planning/decision, and his inadequate visual lookout while buzzing, which resulted in failure to see-and-avoid the top (ground/static) wires of an electrical power line.