LAX88FA148

Before the acdnt, witnesses observed the acft circling in a valley beneath a low cloud layer & below the surrounding hilltops. They estimated the ceiling was 400' obscured. Two witnesses said the acft entered clouds before it crashed. A 3rd witness, who was a plt, said the acft was at a very low alt when it apchd rising/mountainous terrain; he said the acft then entered a steep climbing turn & stalled after making 2 complete turns. Impact occurred in a nose low, left wing down attitude. No preimpact mechanical problem was found. The FAA had issued the plt a special 3rd class med cert after he had quintuple heart bypass surgery. He was rprtd to have gotten 'quite angry' before the flt, when 2 paxs were late. A pathologist believed the plt's death may have been due to arteriosclerotic heart disease; however, this was not verified. The plt did not have an instrument rating & no record of a preflt wx briefing was found.