FUEL DELIVERY SYSTEM

A fuel delivery system for a gas turbine engine (103) comprises a cryogenic fuel tank (104), a first fuel line (601) for connection to the cryogenic fuel tank (104), a fuel pump (301) connected to receive fuel via the first fuel line (601), a plurality of fuel lines (602-606) connecting the fuel pump to a combustor (207) of the gas turbine engine (103), a controller (613) configured to operate the fuel delivery system, a purge gas tank (611) connected to the first fuel line (601) and configured to store a purge gas for purging the plurality of fuel lines (602-606) and a fuel gas tank (612) connected to the first fuel line (601) and configured to store a fuel gas for flushing purge gas from the plurality of fuel lines (602-606).