A gas turbine engine for an aircraft comprising: an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan comprising a plurality of fan blades; and a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, wherein: the gearbox has an epicyclic gear train comprising a sun gear, a plurality of planet gears and a ring gear, each planet gear being rotatable about its own axis on a respective pin, with a journal bearing formed between each planet gear and its respective pin; wherein, each pin has a passage (310, 320) running therethrough in the axial direction of the pin; and a first oil supply system is arranged to provide an oil supply to the journal bearing via a first journal bearing supply channel formed through the pin; a second oil supply system is arranged to provide an oil supply to the journal bearing via a second journal bearing supply channel formed through the pin, the second oil system being different to the first oil system; characterised in that the first journal bearing supply channel and the second journal bearing supply channel extend between the passage and the journal bearing so as to fluidly connect the passage to the journal bearing; wherein the second journal bearing supply channel is parallel to the first journal bearing supply channel; and at least one of the second journal bearing supply channel and the first journal bearing supply channel is formed through the respective pin in a direction that is not a radial direction of the pin. an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan comprising a plurality of fan blades; and a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, wherein: the gearbox has an epicyclic gear train comprising a sun gear, a plurality of planet gears and a ring gear, each planet gear being rotatable about its own axis on a respective pin, with a journal bearing formed between each planet gear and its respective pin; wherein, each pin has a passage (310, 320) running therethrough in the axial direction of the pin; and a first oil supply system is arranged to provide an oil supply to the journal bearing via a first journal bearing supply channel formed through the pin; a second oil supply system is arranged to provide an oil supply to the journal bearing via a second journal bearing supply channel formed through the pin, the second oil system being different to the first oil system; characterised in that the first journal bearing supply channel and the second journal bearing supply channel extend between the passage and the journal bearing so as to fluidly connect the passage to the journal bearing; wherein the second journal bearing supply channel is parallel to the first journal bearing supply channel; and at least one of the second journal bearing supply channel and the first journal bearing supply channel is formed through the respective pin in a direction that is not a radial direction of the pin. the gearbox has an epicyclic gear train comprising a sun gear, a plurality of planet gears and a ring gear, each planet gear being rotatable about its own axis on a respective pin, with a journal bearing formed between each planet gear and its respective pin; wherein, each pin has a passage (310, 320) running therethrough in the axial direction of the pin; and a first oil supply system is arranged to provide an oil supply to the journal bearing via a first journal bearing supply channel formed through the pin; a second oil supply system is arranged to provide an oil supply to the journal bearing via a second journal bearing supply channel formed through the pin, the second oil system being different to the first oil system; characterised in that the first journal bearing supply channel and the second journal bearing supply channel extend between the passage and the journal bearing so as to fluidly connect the passage to the journal bearing; wherein the second journal bearing supply channel is parallel to the first journal bearing supply channel; and at least one of the second journal bearing supply channel and the first journal bearing supply channel is formed through the respective pin in a direction that is not a radial direction of the pin.