A300 flight crew reported receiving a master caution and an ECAM warning for Green System Hydraulic Low Pressure. The crew continued to the destination after coordinating with ATC; dispatch; and company maintenance; where a landing was made and the aircraft was towed from the runway.
Synopsis
A300 flight crew reported receiving a master caution and an ECAM warning for Green System Hydraulic Low Pressure. The crew continued to the destination after coordinating with ATC; dispatch; and company maintenance; where a landing was made and the aircraft was towed from the runway.
Narrative
At approximately XA:25; we received a Green HYD SYS LO PR Caution at cruise approximately 50 NM from TOD (Top of Descent). The Green Hydraulic System Reservoir Level Indications on the overhead panel and ECAM showed Low Fluid Level in the Green Hydraulic System. We began executing the ECAM and QRH procedures; briefed a game plan for recovering at ZZZ and [advised] ZZZ Center just prior to TOD. Sent a brief ACARS message to Dispatcher to apprise them of our situation and that we would require a tow upon landing. Also coordinated with ZZZ Ops via radio for a tug. Manually extended the landing gear in accordance with the QRH (Green System Hydraulic Fluid Reservoir Indications jumped back into the normal range as soon as the landing gear handle was placed in the down position). Conducted a visual approach to [Runway] XXL and stopped on the runway without incident. Crash Fire Rescue (CFR) conducted a cursory exterior inspection of the aircraft for evidence of a hydraulic fluid leak while awaiting the tug. Hydraulic Fluid was discovered leaking from the Left Engine Drain Mast upon arrival at the gate. Loss of Green System Hydraulic Pressure and Fluid. This was a failure of a single hydraulic component/system in an aging airframe. The redundant hydraulic systems; emergency procedures and alternate gear extension/braking systems worked as advertised. ATC; Crash Fire Rescue; Company Maintenance; and Operations Personnel all contributed to a safe and professional resolution of the incident. I do not know how it could have been prevented but I do think it validated the training; communication; and procedures for those agencies and personnel involved.
Second reporter narrative
At FL320; 20 miles prior to top of descent (150 miles of flying remaining) on the STAR in ZZZ; we received a Master Caution and an ECAM Warning for Green System Hydraulic Low Pressure. The synoptic page showed the Green Fluid Level in the Amber with only 50 PSI of Pressure. The overhead panel showed the Green Fluid Hydraulic Level at the red dot in the Amber zone. The Captain (CA) and I verbalized what we saw; agreed that it looked legitimate; and he established duties - he would fly and I would run the problem. The ECAM directed us to shut off both Green Hydraulic Pumps; and to reference the Quick Reference Handbook for single system low hydraulic pressure. We turned off the Green Pumps; which turned off Autopilot 1; so we selected Autopilot 2. The QRH checklist directed us to turn our Brake Anti-Skid switch to alternate/on; guaranteeing some anti-skid with Yellow Hydraulics. We complied with this step; but the ECAM never turned the step from blue to white indicating completion. We each cycled the switch to ensure it was in the correct position. The procedure also had us reference increased landing distance charts; landing speed increment charts; fuel consumption increased charts; and a landing gear alternate extension checklist. Additionally it referenced the need to add 5 knots to our hook speed; flap speed; and slats speed. The QRH sent us to the Hydraulic Reservoir Low Level checklist which had us to turn off Pitch Feel 1; Spoiler 6; and examine the QRH table to identify which systems had been lost (Kruger Flaps; Auto Brakes; Autopilot 1; Pitch Trim 1; Pitch Feel 1; Nose Wheel Steering; Standby Generator); and which systems would be slow (Slats; Flaps; Spoilers). Throughout the entire recovery; the ECAM chime continued to ring and cycle through the pages as if new steps or problems were occurring; even though we accomplished the steps and cleared the ECAM; it would constantly return; re illuminate the Master Caution; and change pages on us. It was a major distraction; particular for communication. None of the following prevented the ECAM from continuing to chime (every 5-10 seconds): ECAM clear button; Master Caution button; normal Warning Silence button. Also; this was a dry ice supplementary procedures flight; meaning we had significant amounts of dry ice on board; requiring us to wear CO2 monitors and note the levels. Because of the additional workload and communication and steps during the situation; the monitors frequently went off with an alert as occasional exhalation would set off the monitor alert function. This was another distraction; but we could mitigate it by confirming the alert level was low; and silencing the audible warning (until the process repeated). Before I computed landing distances; speeds; and fuel consumption; we discussed our game plan and I suggested we fly the normal STAR; get vectors in the terminal area for a 20 mile extended final as configuration would take longer and we'd have to crank down our gear. The Captain concurred and we agreed to request Runway XXL because we'd be shutting down the runway with no steering; and it was the main recovery window for company to [Runway] XXR. We also agreed we'd need to coordinate a tow. I coordinated our plan with ZZZ Center; while the Captain flew and rebuilt the new STAR and approach in the FMS and ILS head. We completed the QRH; briefed the star and approach; and ran our normal checklists. The Captain contacted the Dispatcher via ACARS to give them a heads up; and I contacted company ramp tower at ZZZ to request their help in getting a tug out to [Runway] XXL. We executed our plan; configured in accordance with our brief; additionally briefed the non-standard go-around procedure that was required should we need it; as well as braking and distance considerations. I manually cranked the gear down. Before we completed the final steps of the landing gear alternate extension checklist; we were concerned because we had gear unlocked red indications; plus the green gear down lights. But once we put the landing gear handle down per the QRH; the unlocked lights extinguished. Additionally; at that point; the fluid level in the reservoir returned almost to normal. The Captain made a very nice heavyweight landing; we stopped on the runway; and spoke with Airport Rescue and Firefighting (ARFF) to inspect the plane for any fluid leaks on the plane or runway. None were found; so we coordinated our tug and escort back to the gate; where it was discovered that hydraulic fluid was dripping out of the left engine. A loss of hydraulic fluid and pressure in the green system; later determined to be an engine pump pressure switch leak. It couldn't have been prevented. Parts occasionally fail after sufficient hours and cycles of use.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.