B717 (Formerly MD-95)
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Landed As Precaution; Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Declared Emergency
Aircraft; Procedure
[On a previous flight we] had a HYD R QTY Lo alert. The next day; we operated the same aircraft. The aircraft hydraulics had been serviced and the logbook was signed off by Maintenance. After we departed; at about FL180; the hydraulic quantity was noted as decreasing below 9 units. Approximately 40 minutes into the flight; the hydraulic quantity was decreasing to below 7 units. Contact was made with Dispatch and Maintenance via Commercial Radio. Maintenance recommended that we land in [a nearby suitable airport]. As we approached [destination] the HYD QTY LO alert illuminated; and an emergency was declared the QRH was run; and checklists completed. We landed uneventfully.After arriving at the gate I had a chance to talk with Maintenance and see what caused the loss of hydraulic fluid. The right main gear hydraulic actuator line for retracting the gear was leaking and seeping through the line. This would not have been noticed with the gear extended and difficult to identify on a walk around preflight inspection.
B717-200 First Officer reported loss of right hydraulic system fluid; resulting in the crew declaring an emergency and diverting to the nearest suitable airport. First Officer mentioned the system had been serviced by Maintenance the day before following a loss of fluid.