An upright partition that separates one aircraft compartment from another is called what?

The correct terminology for an upright partition that separates one aircraft compartment from another is a bulkhead. Bulkheads play a crucial role in the structural integrity of the aircraft, as they provide support and help maintain the overall shape. Additionally, they serve to compartmentalize the aircraft, which can be essential for safety—particularly in the case of a fire or other emergencies—by containing potential hazards to a specific area.

This structural feature is particularly important in commercial aviation, where the design not only serves mechanical purposes but also contributes to passenger safety by creating distinct compartments. In contrast, a canopy refers to the transparent covering over the cockpit, the empennage pertains to the tail assembly of an aircraft, which includes the horizontal and vertical stabilizers, and an aileron is a control surface on the wing that helps to manage the aircraft's roll. These terms do not relate to the function of separating spaces within the aircraft like a bulkhead does.