As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DFW - FLT 3506 - SULFUR LIKE SMELL IN THE COCKPIT. NO SMOKE. ALL INDICATIONS WERE NORMAL. HOWEVER, THE TCAS FELL OFF LINE AT THE SAME TIME. INSEPCTED TCAS CONNECTORS WITH NO DEFECTS NOTED. REMOVED AND REPLACED TCAS COMPUTER. OPERATIONAL CHECK GOOD. AIRCRAFT RETURNED TO SERVICE. (M)