As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EWR/RIC - FLT 6470 - DURING TAXI AT 1645 HOURS ON 4-16-97. RETURNED TO GATE DUE TO RT DUCT FAIL WARNING LIGHT ILLUMINATED. MAINTENANCE INSPECTED AND REMOVED AND REPLACED DUCT COUPLING O-RINGS, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)