Incident Overview
On an unspecified date, at approximately 2017 Eastern Daylight Time, approach control cleared the pilot of a Beech J35 to descend from 7,000 feet to 2,500 feet and began providing vectors for an Instrument Landing System (ILS) approach. About nine minutes later, approach control advised that radar contact was lost, but no reply was received from the pilot.
Loss of Instruments
At about 2042, radio contact was reestablished. The pilot stated that he had lost his "level instruments" and would return to Terre Haute, Indiana. Subsequent transmissions revealed a loss of the attitude and heading indicators. The pilot continued flying for a while but was unable to control his altitude, airspeed, or heading.
Crash and Witness Account
At approximately 2109, the aircraft crashed in a wooded area. A witness reported seeing the plane go in and out of clouds, which he estimated were about 100 feet thick. He stated that the plane then circled for about one to two minutes, climbing and diving. The witness also said he saw the plane just as it came out of the clouds and went into the trees about 600 yards from his position.
Aircraft Information
The Beech J35 is optionally equipped with vacuum-operated directional and attitude gyros, which may have been relevant to the instrument failures experienced.