Cooled gas turbine aerofoil

A cooled gas turbine aerofoil comprising:

• an aerofoil profiled section defined by a suction surface and a pressure surface both supported by an internal structure, the aerofoil profiled section having a leading edge, containing a plurality of leading edge exit holes, and a trailing edge, containing a plurality of trailing edge exit holes;
• and
• an internal fluid cooling system comprising a plurality of multi-pass cooling arrangements, each of which includes a serpentine passage which, in operation, receives a cooling fluid from an external fluid source, wherein:
• a first serpentine passage receives the cooling fluid through a first inlet towards the leading edge of the aerofoil profiled section, and supplies the cooling fluid to the plurality of leading edge exit holes before the cooling fluid flows through the first serpentine passage in a general direction that is away from the leading edge of the aerofoil profiled section;
• a second serpentine passage receives the cooling fluid through a second inlet;
• and
• the first and the second serpentine passages are disposed side-by-side, on opposite sides of a main load carrying member in the internal structure of the aerofoil, one adjacent the suction surface of the aerofoil and the other adjacent the pressure surface of the aerofoil.