C-GTSD, an Airbus 330-300 aircraft operated by Air Transat, was conducting flight TSC318 from Montreal/Pierre Elliott Trudeau Intl, QC (CYUL) to Lisbon/Aeroporto da Portela de Sacavem,Portugal (LPPT) with 10 crew members and 316 passengers on board. During cruise flight approximately 180 nm East of CYUL, the aircraft experienced a hydraulic leak in the green system.
The flight crew executed all ECAM actions and QRH checklist items, and declared an emergency.
A return to CYUL was also requested where the aircraft landed without further incident.
The operator’s maintenance replaced a union and an O ring on the Green System High Pressure Filter Manifold.
The aircraft was then returned to service.