What was found
CREW REPORTED A SLAT FAIL MSG DURING TAKEOFF ROLL FROM JAX, CREW DECLARED EMERGENCY AND RETURNED TO FIELD AT JAX AND LANDED WITHOUT INCIDENT. OCM PERFORMED OPERATIONAL CHECKS OF SLAT SYSTEM PER EMB AMM AND REPORTED NO DEFECTS FOUND, A/C WAS THEN RETURNED TO SERVICE. THE A/C LANDED WITHOUT ANY FAILURES INTO DCA ON NEXT FLIGHT. DUE TO FAULT CODES FOUND IN THE CMC, MAINTENANCE REMOVED AND REPLACED BOTH RT 2/3 AND 3/4 SLAT SKEW SENSORS PER EMB AMM AND PERFORMED OPS CHECKS.