Accident Overview
A single-engine aircraft on a night instrument flight rules (IFR) flight experienced a loss of directional control and subsequently collided with terrain. The accident occurred after the pilot reported a failure of the directional gyro while flying at 7,000 feet mean sea level (MSL) in instrument meteorological conditions (IMC).
Sequence of Events
The aircraft was outbound from the Pulaski VOR on airway V45, heading southeast. The pilot reported to air traffic control (ATC) that the directional gyro was inoperative, but confirmed that the turn-and-bank indicator and magnetic compass were still operational. Shortly thereafter, the pilot indicated an inability to maintain the correct course. The aircraft eventually reversed course. While ATC was attempting to assist the pilot in returning to the proper heading, the aircraft descended and struck the ground.
Environmental Conditions
Witnesses near the accident site reported poor visibility, low clouds, and fog. These conditions were consistent with IMC.
Aircraft Systems Examination
Investigators could not accurately determine the aircraft's IMC capability due to extensive fire and impact damage. Examination of the engine-driven vacuum pump did not reveal conclusive evidence of failure. The aircraft was equipped with a standby vacuum system, but its operation could not be confirmed after the accident.
Pilot and Flight Information
The pilot had flown an initial leg of 4.0 hours to drop off passengers and was returning to his home base. On the return leg, the aircraft had flown approximately 3 hours at the time of the accident.