Water tanks

Water Tanks: Special model testing tank for ascertaining in advance the probable behaviour of flying-boat hulls when water-borne.
Weather: The state of the atmosphere with reference to climatic conditions.

Water cartage (to refill fresh water tanks)
Air conditioning (more common for smaller aircraft)
Airstart units (for starting engines)
Luggage handling, usually by means of beltloaders and baggage carts ...

See also: Power, Plane, Speed, Tanks, Aircraft