As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED DURING CLIMB EN ROUTE TO PHL THE CAPTAIN'S AIRSPEED WAS NOTED TO BE 30 KNOTS LOWER THAN THE F/O'S. CREW DECLARED AN EMERGENCY AND RETURNED TO MSY. LANDED WITHOUT INCIDENT. MX TROUBLESHOT AND REMOVED AND REPLACED ADSP 1 PER EMB AMM.