Incident Overview
The pilot initiated an approach to Iowa City Airport under night conditions with marginal weather. Due to poor visibility, he executed a go-around and followed a circuit for several minutes before commencing a second approach. With visibility reported as half a mile and a ceiling of 300 feet, the pilot continued the approach and descended below the minimum descent altitude (MDA). The airplane subsequently struck the ground and was destroyed. All four occupants sustained injuries.
Circumstances
The approach was conducted at night. The pilot reported that the VOR DME fluctuated during the approach. The aircraft's right alternator was noted as inoperative. The weather conditions included low ceiling (300 feet), half-mile visibility, and rain. The pilot descended below the published MDA on the second VOR approach.
Probable Cause and Factors
The official probable cause was improper IFR operation on the part of the pilot. The following factors were reported: electrical failure; low ceiling (300 feet), 0.5 mile visibility, rain; the pilot stated that the VOR DME fluctuated; the right alternator was inoperative; and the pilot descended below the published MDA on the second VOR approach.