As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BWI - FLT 2620 - AFTER TAKEOFF, THE STANDBY HYDRAULIC QTY LIGHT ILLUMINATED. FLIGHT RETURNED TO FIELD AT BWI AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGNCY WAS DECLARED. MAINTENANCE REMOVED AND REPLACED THE CANNON PLUG FOR THE STANDBY HYDRAULIC LOW QUANTITY SWITCH. (M)