NTSB Factual Report

HISTORY OF FLIGHT

On August 12, 2006, about 1009 eastern daylight time, an amateur-built Acro Sport II, N208BY, piloted by a private pilot, was substantially damatged by impact forces and a post-impact fire following a forced landing due to a loss of engine power near Coldwater, Michigan. The pilot received serious injuries and the passenger received fatal injuries. The flight originated from the Jackson County Airport, Jackson, Michigan, at an unconfirmed time and was destined for the Branch County Memorial Airport (OEB), Coldwater, Michigan.

In a telephone interview, the pilot stated that he attempted a landing toward the east (runway 07 at OEB), and during the landing, a gust of wind "caught" him and he performed a go-around. He said that at about 200 feet above the ground, during the go-around, the engine went to idle. He stated that it was as if the throttle became disconnected. He said that he did not have time to restart the engine. He said that the engine had a wood propeller that would not windmill and the prop stopped. He selected a field to land in and said that during the landing the airplane struck a ditch that he did not see from the air. When the airplane came to a stop, it caught fire.

PERSONNEL INFORMATION

The pilot held a private pilot certificate with a single-engine land rating. His most recent third class medical certificate was issued on April 30, 2006. During a telephone interview, the pilot estimated having 80 hours in the accident airplane and in excess of 1,000 hours of total flight experience.

AIRCRAFT INFORMATION

The airplane was an amateur built Acro Sport II, serial number RED243. The pilot was listed as the builder of the airplane. The Acro Sport II is a single-engine biplane with a tailwheel landing gear arrangement. The fuselage and tail surfaces are constructed of a steel tubing truss type framework with fabric covering. The wings were of wood construction with fabric covering. The airplane could seat two occupants in a tandem seat configuration. The airplane was powered by a Lycoming O-320-H2AD, serial number L-763-76.

METEOROLOGICAL INFORMATION

The recorded weather at OEB at 1015 was: wind from 100 degrees at 8 knots; visibility 10 statute miles; sky condition clear; temperature 19 degrees Celsius; dew point 14 degrees Celsius; altimeter setting 30.14 inches of Mercury.

AIRPORT INFORMATION

OEB is an uncontrolled public use airport located about 3 miles west of Coldwater, Michigan. It has two paved runways, and one turf runway. Runway 07/25 is the longest runway and is an asphalt runway 5,350 feet long and 75 feet wide. Runway 04/22 is the second asphalt-paved runway and is 3,500 feet by 75 feet. The turf runway, runway 16/34, is 2,400 feet long and 190 feet wide.

WRECKAGE AND IMPACT INFORMATION

The airplane came to rest upright in a rolling field that was adjacent to a corn field. Ground impact marks were found in the field immediately adjacent to the corn field. The airplane came to rest facing away from the corn field with its tail about 25 feet from the corn crop. The corn was standing about five feet tall. There was no evidence that the airplane had struck the corn crop. The terrain in the immediate area of the wreckage was rising in the direction that the airplane was headed. Photographic evidence did not show a ditch between the corn field and the field where the airplane came to rest.

The main landing gear had collapsed and was beneath the fuselage. The upper wing, inboard lower wing, rear cowl, and the entire cockpit section of the airplane received extensive fire damage. The tail surfaces remained intact and attached to the airplane. The wooden propeller was in a horizontal position and was not damaged. No anomalies were found with respect to the airframe or the flight control systems.

The engine was later examined and the details of the examination can be found in the Tests and Research section of this report.

TESTS AND RESEARCH

The engine was examined on September 20, 2006. The engine had fire damage to its aft end that included the magneto and rear cylinders. The carburetor and air box were destroyed by impact damage. The spark plug leads were burned off between the magneto and plugs. The engine did not have a vacuum pump installed. The rocker covers were removed and valve train continuity was confirmed by rotating the engine by hand. Compression was verified on all cylinders by placing a finger over the upper spark plug holes while rotating the engine. The spark plugs showed normal wear with no evidence of fouling. The oil sump was removed and trace amounts of oil were present. The oil had been drained from the engine to place it on the stand. No foreign materials were found in the sump. The induction tubes between the oil sump and cylinders were intact, the hoses were tight and there was no evidence of leakage. All of the cylinders were removed. The pistons, rings, and cylinder walls showed no signs of abnormal wear. The intake and exhaust valves and seats showed no anomalies. The mechanical fuel pump was removed and a small amount of fuel was found in the pump. The fuel was blue in color, had the smell of 100LL aviation gasoline, and no contamination was apparent. The engine case was disassembled. The crankshaft, camshaft and bearings showed no signs of abnormal wear. The aft journals showed heat related damage from the fire. No foreign matter was found in the case. The magneto had fire related damage. The impulse coupling operated when the engine was rotated. The magneto was disassembled and magneto drive continuity was confirmed. The points, coils and condensers had fire related damage and their condition could not be determined. The carburetor finger screen was found attached to the fuel hose. Inspection of the screen showed only a minor amount of foreign material in the screen. The carburetor throttle plate was found attached to the carburetor arm. It showed no evidence of abnormal wear or fuel staining. The engine ring gear had one (1) tooth broken off. The rear alternator case half was cracked.

ADDITIONAL INFORMATION

The Federal Aviation Administration was a party to the investigation.

NTSB Probable Cause

The loss of engine power for undetermined reasons and the pilot's failure to maintain sufficient airspeed during the resulting forced landing which resulted in the inadvertent stall and subsequent impact with the ground. The rising terrain was a factor.