Accident Overview
During cruise flight at 6,000 feet, the left engine of a twin-engine airplane lost power. The pilot attempted to restart the engine but observed only about one-half rotation of the propeller before securing it. Unable to maintain altitude, the pilot initiated a descent and requested an instrument approach to an airport where weather conditions were reported as 1/4 statute mile visibility, fog, and a vertical visibility of 100 feet.
Flight Sequence
On the first approach, at the minimum descent altitude, the pilot executed a missed approach. As the airplane climbed, the pilot reported to the controller that the best altitude he could achieve was 2,200 feet. A second approach was initiated to the reciprocal runway. During this approach, the pilot told the controller he intended to fly the airplane directly to the runway. He lowered the landing gear, reduced power, and decided there was no hope for a go-around. The pilot then flew below the decision height. At approximately 70–80 feet above the ground, he added a little power to smooth the landing. The pilot stated that the last thing he remembered was the airplane's nose contacting the runway.
A passenger reported that once the pilot could not see the runway, the pilot applied power, pitched the nose up, and attempted a go-around similar to the one executed on the first approach.
Engine Examination
Disassembly of the left engine revealed that the crankshaft was fatigue fractured between connecting rod journal number 2 and main journal number 2.
Performance Data
Review of the pilot's operating handbook indicated that the single-engine service ceiling at a weight of 4,800 pounds was 11,700 feet. The average single-engine rate of climb at a pressure altitude of 6,000 feet was 295 feet per minute, and at a pressure altitude of 1,625 feet was 314 feet per minute. Review of the ILS approach plate for Runway 34 showed that the decision height was 200 feet above ground level.
Probable Cause
The pilot's improper in-flight decision to descend below the decision height without the runway environment in sight, and his failure to execute a missed approach. A factor in the accident was the failed crankshaft.