On December 19, 2001, at 2050 Pacific standard time, a Cessna T210N, N7AL, impacted an airport boundary fence during landing on runway 28R at Montgomery Field Airport, San Diego, California. The airplane was operated by the owner under 14 CFR Part 91. The private pilot and two passengers were not injured. The airplane was substantially damaged. The local area, post maintenance check flight departed from Montgomery Field at 2000. Night, instrument meteorological conditions prevailed, and the flight was operating on an instrument flight plan. The Montgomery Field weather, observed at 2053, was visibility 1/4 statute mile, vertical visibility 100 feet, with temperature and dew point both 9 degrees Celsius. A sheriff's deputy reported from the accident site that the visibility was 50 to 100 yards in fog. The pilot reported that the accident occurred as he was returning to the departure airport following a 40-minute post maintenance checkflight. He received the airport weather from the Automatic Terminal Information Service (ATIS) recording and was aware that ground fog had developed at the airport. He received air traffic clearance and executed the instrument landing system (ILS) approach to runway 28R. At decision height he was still in visual meteorological conditions and the runway and approach lighting were in sight. The pilot continued his descent below decision height by visual reference and encountered dense fog and severe restriction to visibility at 50 to 75 feet above ground level. The pilot did not feel a go-around was possible at that point and continued the landing approach. The airplane landed long and continued off the end of the runway into a chain link fence.