The insulation in the aircraft is thermal acoustic. It keeps heat and decreases noise in the flight compartment, the entrance area, the passenger compartment, and the baggage and aft equipment compartment. It is found above and below the floor around the circumference of the fuselage the from approximately FS195.00 to FS669.00.

The insulation is a blanket type insulation made of 4 layers. The layers are solimide 0.5 inch (1.27 mm), fiberglass 1.5 inches (3.81 mm), solimide 0.5 inch (1.27 mm) and solimide 0.25 inch (0.635 mm). These layers are bagged in orcon.

Insulation blankets are installed between the frames and around/over the frames as follows:

• In the flight compartment outboard of the interior liner panels
  
  
• In the entrance area outboard of the interior liner panels, the LH wardrobe closet, the RH crew closet, the RH galley, and the LH and RH equipment racks
  
  
• In the passenger compartment outboard of the interior liner panels, the passenger service units, the lower sidewall panels, the window panels, the aft partition, the LH vanity cabinet and the toilet
  
  
• In the baggage compartment and aft equipment compartment outboard of the interior and internal baggage compartment liner panels and baggage compartment exterior door.

Insulation blankets are also installed on the forward face of the aft pressure bulkhead at FS669.00 and sandwiched between the baggage compartment liner panels and the bulkhead structure.

The entry door insulation is a self-adhesive foam product bonded on the outer skin of the door and on the inboard faces of the airstairs.