a gas turbine combustor arrangement involves two combustion chambers separated by a necked down throat portion with provision for fuel introduction into each of the chambers . initially , fuel is introduced into the first chamber and ignited . thereafter , fuel is introduced into the second chamber until the total fuel flow to the combustor is at the desired rate . burning in the first chamber is then extinguished by shifting fuel flow to the second chamber and after burning termination , the fuel distribution is reversed until a low emission operation is realized . apparatus for carrying out the foregoing method and a high load ingition system is also disclosed .