Accident Overview
A pilot experienced a loss of gyroscopic instruments while operating in instrument meteorological conditions (IMC) during a flight to Conroe, Texas. The pilot received three separate weather briefings in the six hours before departure, each forecasting IFR conditions. While en route, the pilot contacted Houston Approach Control and reported, "I lost my gyros."
Attempted Assistance
In response, Houston Approach Control provided no-gyro vectors to assist the pilot in aligning the aircraft for an Instrument Landing System (ILS) approach to runway 8 at Houston Intercontinental Airport. Despite these instructions, the pilot lost control of the aircraft, which subsequently impacted the ground.
Weather Conditions
Weather observations from David Wayne Hooks Municipal Airport, located 10 nautical miles northeast of the accident site, at 1850 Central Standard Time reported: estimated ceiling 500 feet above ground level overcast, visibility 1 mile with fog, temperature 57°F, dew point 56°F, winds from 070° at 6 knots, and an altimeter setting of 30.17 inches of mercury.
Mechanical Examination
Post-accident examination of the vacuum pump input shaft by a National Transportation Safety Board metallurgist revealed that the shaft failed due to sudden stoppage of the vacuum pump. This failure likely led to the loss of gyroscopic instruments.