Structural Certification and In-service Flight Experience of the RB 211–524 Fan Cowl Doors Utilising Carbon Fibre Composite Materials

Abstract

For structural applications at temperatures up to 150°C graphite epoxy (Gr/Ep) materials offer the prospect of minimum structural at weight for a given strength and stiffness. Epoxies have properties which make them the most frequently used polymer matrix materials in aircraft composite components.

The RB 211–524 cowl doors gave Rolls-Royce the opportunity to introduce a large Gr/Ep structure into passenger carrying service. This pioneering effort was the first civil aircraft application of such a structure.

The Gr/Ep advanced composite cowl door was designed as a light weight replacement for an aluminium door. This component was recognised as a good example of a refined aluminium aircraft structure, its design optimised to minimum weight. Compared with this as a datum the composite door gave a significant weight reduction.

The doors were designed by Rolls-Royce and manufactured by British Aerospace Weybridge, in a programme which developed the fabrication technology and also yielded valuable in-service experience.

This paper describes the design objectives, structural certification programme and in-service support.