Aerial Apparatus
Apparatus built around a hydraulically operated ladder or elevating platform, for reaching height, rooftop work and elevated water streams.
An aerial carries a powered ladder or a platform on a boom. It exists for what a ground ladder cannot reach: upper floors, roof access, rescue from height, and water applied from above.
Straight aerials and platforms are different tools. A platform, sometimes called a tower, puts a working basket at the tip and suits rescue and sustained elevated work; a straight stick is lighter and cheaper and suits access and stream placement. Departments choose on their building stock, not preference.
For a fleet manager the important characteristics are physical and financial. Aerials are heavy, long and demanding on stations, approaches and turning space, and the aerial device carries testing and certification obligations separate from the chassis. That is a recurring cost and a scheduling commitment, not a one-off.