A fire-suppression system for use in an aircraft having at least one cargo compartment is disclosed. Methods of suppressing a fire in the cargo compartment are also disclosed. The fire-suppression system, under one aspect of the present invention, can include at least one fire-suppressant vessel, at least one discharge conduit coupled to the at least one fire-suppressant vessel, and a valve arrangement coupled to the fire-suppressant vessel and the discharge conduit. The valve arrangement can have a first setting to discharge a fire suppressant at a first discharge rate after activation of the fire-suppression system, a second setting to discharge the fire-suppressant at a second discharge rate less than the first discharge rate, and a third setting to discharge the fire-suppressant at a third discharge rate greater than the second discharge rate during descent of the aircraft.