飞机的整个增压部分完全衬有隔热/隔音材料，这是迄今为止飞机中非金属材料量最大的部分。 隔热层的声学要求比热要求更高。 所使用的隔热毯结构包括被防护层包裹的棉絮； 但是，在某些绝缘材料由泡沫或毛毡组成的应用中，没有使用单独的防护层。 隔热层和防护层必须符合FAR 25.853（b）的要求。
C.3 Insulating Materials
The entire pressurized section of the aircraft is completely lined with thermal/acoustical insulation, which is by far the largest volume of nonmetallic material in an aircraft. The acoustical requirements for the insulation are more demanding than the thermal requirements. The insulation blanket construction used consists of a batting surrounded by a protective cover; however, in some applications, where the insulating material consists of foams or felts, a separate cover is not used. Insulation batting and covers are required to meet FAR 25.853(b).