A gas turbine engine comprising a combustion volume, a radial swirler having main-fuel injection holes (76, 77) for injecting a main fuel flow, the radial swirler comprising an annular array of swirler vanes arranged circumferentially spaced around an annular base plate so as to form, between adjacent swirler vanes, slots, and a pilot burner assembly which is generally surrounded by the radial swirler, wherein the pilot burner assembly comprising: - a pilot burner comprising a burner face having a plurality of pilot-fuel injection holes adapted to provide a pilot-fuel to the combustion volume for combustion; - a pilot-fuel supply line fluidly connected to the pilot-fuel injection holes and adapted to provide the pilot-fuel to the pilot-fuel injection holes; and - a pilot-air supply line adapted to provide a pilot-air to the pilot burner and wherein the pilot-air is supplied to the combustion volume through the burner face, - a pilot-air valve adapted to control a flow of the pilot-air in the pilot-air supply line towards the pilot burner, characterised by - a control unit adapted to direct the pilot-air valve to control the flow of the pilot-air in the pilot-air supply line towards the pilot burner such that the pilot-fuel and the pilot-air are provided to the combustion volume in a desired ratio of the pilot-fuel and the pilot-air, - a premixing chamber, wherein the premixing chamber is fluidly connected to the pilot-fuel supply line for receiving the pilot-fuel and to the pilot-air supply line for receiving the pilot-air, and wherein the premixing chamber is adapted to form a pilot-fuel/pilot-air premix within the premixing chamber and comprises an outlet fluidly connected to the pilot-fuel injection holes to provide the pilot-fuel/pilot-air premix to the combustion volume for combustion. a combustion volume, a radial swirler having main-fuel injection holes (76, 77) for injecting a main fuel flow, the radial swirler comprising an annular array of swirler vanes arranged circumferentially spaced around an annular base plate so as to form, between adjacent swirler vanes, slots, and a pilot burner assembly which is generally surrounded by the radial swirler, wherein the pilot burner assembly comprising: - a pilot burner comprising a burner face having a plurality of pilot-fuel injection holes adapted to provide a pilot-fuel to the combustion volume for combustion; - a pilot-fuel supply line fluidly connected to the pilot-fuel injection holes and adapted to provide the pilot-fuel to the pilot-fuel injection holes; and - a pilot-air supply line adapted to provide a pilot-air to the pilot burner and wherein the pilot-air is supplied to the combustion volume through the burner face, - a pilot-air valve adapted to control a flow of the pilot-air in the pilot-air supply line towards the pilot burner, characterised by - a control unit adapted to direct the pilot-air valve to control the flow of the pilot-air in the pilot-air supply line towards the pilot burner such that the pilot-fuel and the pilot-air are provided to the combustion volume in a desired ratio of the pilot-fuel and the pilot-air, - a premixing chamber, wherein the premixing chamber is fluidly connected to the pilot-fuel supply line for receiving the pilot-fuel and to the pilot-air supply line for receiving the pilot-air, and wherein the premixing chamber is adapted to form a pilot-fuel/pilot-air premix within the premixing chamber and comprises an outlet fluidly connected to the pilot-fuel injection holes to provide the pilot-fuel/pilot-air premix to the combustion volume for combustion. - a pilot burner comprising a burner face having a plurality of pilot-fuel injection holes adapted to provide a pilot-fuel to the combustion volume for combustion; - a pilot-fuel supply line fluidly connected to the pilot-fuel injection holes and adapted to provide the pilot-fuel to the pilot-fuel injection holes; and - a pilot-air supply line adapted to provide a pilot-air to the pilot burner and wherein the pilot-air is supplied to the combustion volume through the burner face, - a pilot-air valve adapted to control a flow of the pilot-air in the pilot-air supply line towards the pilot burner, characterised by - a control unit adapted to direct the pilot-air valve to control the flow of the pilot-air in the pilot-air supply line towards the pilot burner such that the pilot-fuel and the pilot-air are provided to the combustion volume in a desired ratio of the pilot-fuel and the pilot-air, - a premixing chamber, wherein the premixing chamber is fluidly connected to the pilot-fuel supply line for receiving the pilot-fuel and to the pilot-air supply line for receiving the pilot-air, and wherein the premixing chamber is adapted to form a pilot-fuel/pilot-air premix within the premixing chamber and comprises an outlet fluidly connected to the pilot-fuel injection holes to provide the pilot-fuel/pilot-air premix to the combustion volume for combustion.