The selection of composite material systems for use in large commercial transport aircraft depends on a number of material characteristics such as mechanical and physical properties, behavior in a hot-wet environment, resistance to delamination, ease of processing, and whether use of thick plies to reduce lay-up time is beneficial.

This paper reviews the design requirements and the key material characteristics needed by the structural designers. It has been well established that the current epoxy systems can be easily delaminated by the impact of external forces. This ease of delamination has resulted in a requirement to increase the toughness of the resin system so that its delamination resistance is two to four times higher than that of current epoxies. Other parameters include hot-wet requirements, low assembly cost potential, long shelf life, ease of processing, drapability requirements, and smoke generation.