As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STL - FLT 1618 - EN ROUTE STL-LGA - DETECTED NR 1 HYDRAULIC SYSTEM SLOWLY DECREASE TO TWELVE PERCENT. ON FINAL APPROACH NR 1 HYDRAULIC SYSTEM LOW LIGHT ILLUMINATED. LANDED JFK WITHOUT FURTHER INCIDENT. REPLACED NR 1 SYSTEM ENGINE HYDRAULIC PUMP O-RING. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)