Triplicate copies of complete drawings with specifications, consisting of floor plans showing the locations of such features as the principal pieces of equipment, floor drains, principal drainage lines, hand-washing basins, and hose connections for cleanup purposes; elevations; roof plans when necessary to show size and location of skylights and the like; cross and longitudinal sections of the various buildings, showing such features as principal pieces of equipment, heights of ceilings, conveyor rails, and character of floors, walls, and ceilings; and a plot plan showing relationship of various departments and structures of the plants, properly drawn to scale, shall accompany applications. Where complete approved drawings and specifications are available in the files of the Meat and Poultry Inspection Program, Food Safety and Inspection Service, U.S. Department of Agriculture, covering a plant operating under the supervision of that Program, it will not be necessary that drawings and specifications accompany an application made under this part for inspection at such plant.