NTSB Factual Report

On March 8, 2003, at 1200 central standard time, a Cessna 172H, N275SW, piloted by a private pilot, was substantially damaged during a forced landing at a private airstrip in Callao, Missouri. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under 14 CFR Part 91 and was not on a flight plan. The pilot reported minor injuries. The flight had departed from the private, turf airstrip approximately 1150 cst, with an intended destination of Macon-Fower Memorial Airport (K89), Macon, Missouri.

According to the pilot's statements, shortly after departure approximately 3 miles west of the airstrip, the engine "started cutting out." He reported that he applied carburetor heat and checked the mixture, however, the engine performance did not improve. At that point the pilot decided to return to the local airstrip.

The pilot stated: "Approximately 1/2 mile away I slowed down and added 20 degrees of flaps. As I approached the threshold end at a heading of 090 degrees, I applied more flaps. The airplane stayed in ground [effect] and didn't land until about 2/3 of the way down the runway. Upon touchdown I took out all flaps as the airplane slid down the grass/muddy runway. The airplane slid off the end of the runway with the nose wheel striking a gravel road and breaking off. The airplane then flipped over coming to rest upside down in the road ditch."

The pilot reported that he decided to approach straight-in for a downwind landing due to the lack of available power, as well as the rising terrain and two sets of power lines east of the airstrip. He noted that he was slightly fast on final approach.

The pilot reported the engine ran smoothly on run-up and during takeoff. No abnormal instrument readings were noted prior to the engine problem, according to the pilot. He added that the mixture control was in the full rich position during start-up, taxi and takeoff.

A post accident examination was conducted. The aircraft was equipped with after-market long range auxiliary fuel tanks. The main fuel tanks were not compromised and contained fuel. The right auxiliary tank was not compromised and was approximately one-half full of fuel. The left auxiliary tank contained a small amount fuel, however, the tank was ruptured. No contaminants were observed in a fuel sample taken from the strainer at the firewall.

Continuity of the engine was verified through crankshaft rotation. Compression was present on all cylinders, with the exception of cylinder 2. No compression was noted on cylinder 2. Piston travel and valve operation appeared to be normal. Continuity of the throttle, mixture and carburetor heat controls was verified.

The number 2 cylinder was removed and the cylinder and piston were inspected. The bottom edge of the piston head was eroded. The damage extended down the side of the piston to a point below the piston rings. In addition, the damage extended completely through the piston. The condition of the piston was consistent with a piston exposed to an elevated operating temperature.

The number 2 piston rings were broken in the area of the damage. The piston and cylinder wall exhibited scoring in the direction of piston travel. The valves for the number 2 cylinder were undamaged and seated properly within the cylinder head.

Both magnetos produced a spark across all leads when rotated. All spark plugs exhibited slight erosion and a slightly enlarged electrode gap. They otherwise appeared to be functional.

In a preflight weather briefing received about 30 minutes prior to the flight, the winds were from 240 degrees at 14 knots, according to the pilot. He was advised that they were expected to shift toward the north later in the day.

Winds reported by the Kirksville Regional Airport (IRK) Automated Surface Observation System (ASOS), at 1155 cost, were from 330 degrees at 17 knots. The accident site was located approximately 20 nm south of IRK.

NTSB Probable Cause

A loss of engine power due to the erosion of the number 2 piston, resulting in loss of compression on that cylinder. Contributing factors were the tailwind, the muddy runway condition, and the roadway and ditch.