Gas turbine pilot burner water injection and method of operation

A gas turbine engine (12) including a water injection system (56) for providing a flow of water (60) to only a pilot diffusion combustion zone (20) of a dual-mode combustor (10) and not to a pre-mixed combustion zone (18) of the combustor. The selective reduction of peak flame temperature in the pilot flame zone provides a maximum reduction in the production of oxides of nitrogen with a minimum consumption of water. The pilot fuel fraction of the combustor may be increased prior to the initiation of the pilot water injection flow. The flow rate of the pilot injection water may be varied as a function of the power level of the gas turbine, and further as a function of the humidity of the ambient air (36).