SWITCHABLE AERO ENGINE DUAL FUEL CONTROL SYSTEM WITH DHFC

A method of operating a dual fuel gas turbine engine (102) includes operating the engine (102) with a first fuel according to a first control loop (202). The method also includes while the engine (102) is operating with the first fuel, bumplessly transitioning the engine (102) to operate with a second fuel, and operating the engine (102) with the second fuel according to a second control loop (204).