Air Canada rouge – Airbus 319-114 – Gear Failure

C-GBHO, an Airbus 319-114 was operating as Air Canada rouge flight ROU1857 from Los Angeles Intl (KLAX) to McCarran Intl, Las Vegas (KLAS). After takeoff, upon the GEAR UP selection, the flight crew received indications of the green hydraulic system failure, and the gear did not retract as commanded. The flight crew executed the applicable QRH drills, confirmed the gear was down and locked, and declared a PAN PAN before returning to KLAX where a full stop landing was completed with ARFF on standby. ARFF conducted external visual inspection and noted no apparent fluid leaks, however the gear doors were open. The aircraft taxiied under its own power to the gate uneventfully.