As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6511 - LGA-IAD - AIRCRAFT RETURNED TO GATE DUE TO LEFT DUCT OVERTEMP AND AIR-OFF WARNING LIGHT ILLUMINATED. MAINTENANCE INSPECTED AND OPENED DMI 06956, MEL 21-1. MAINTENANCE CLOSED DMI 06956 ON 11-05-97 BY REMOVING AND REPLACING TEMP CONTROL VALVE. OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)