Abstract: A firefighting apparatus is adapted for use in a host aircraft comprising a fuselage defining an interior and an exterior. The firefighting apparatus includes a pressurizeable retardant tank disposed in the interior of the host aircraft, the retardant tank being capable of roll-on and roll-off installation, an ejection tube in fluid communication with the retardant tank, and a door plug for mounting within a fuselage orifice in the host aircraft. The door plug provides for fluid communication of retardant from the retardant tank through the ejection tube to the exterior of the host aircraft. At least one sensor is operably connected to the firefighting apparatus to effect user-discernable data for effecting retardant delivery.