A PASSENGER DIED AFTER A RAPID DECOMPRESSION AND EMERGENCY DESCENT. THERE WAS NO DAMAGE TO THE AIRPLANE OR INJURY TO THE REMAINING OCCUPANTS OF THE AIRPLANE. AN INVESTIGATION REVEALED THAT AN UNCONTROLLABLE OUTFLOW VALVE RESULTED IN A RAPID DECOMPRESSION AT FL 310. THE OXYGEN MASKS DEPLOYED & THE CPT MADE AN EMERGENCY DESCENT TO 10,000 FT, THEN CONTINUED TO DAYTON, LANDING AT 1740. THE PASSENGER WAS TAKEN TO A DAYTON HOSPITAL AND DIED AT ABOUT 6 HOURS AND 50 MINUTES LATER. THE MONTGOMERY COUNTY CORONER RULED THAT DEATH WAS DUE TO NATURAL CAUSES.