aesthetics and ergonomic considerations of aeroplane

Design and Function Requirements for Aircraft Interior Materials
For the purposes of this study, the interior of an aircraft is considered to be everything that is contained inside the pressure shell, that is, the pressurized part of the aircraft fuselage. The regulatory requirements of Federal Aviation Requirements (FAR), Part 25, that apply to interiors fall in FAR 25.853, Compartment Interiors, and FAR 25.855, Cargo or Baggage Compartments. Although FAR 25.853 has the introductory terms ''For each compartment occupied by the crew or passengers, the following applies,'' items that ate not strictly in the occupied compartment (i.e., are outside the cabin liners and not visible to either crew or passengers, such as "electrical conduit, thermal and acoustical insulation and insulation covering, air ducting," are specifically cited and the regulatory requirements are also applied to them.