The Wartime Repair of Bristol Aeroplanes

TWO items which frequently appeared on the repair lists for the Beaufort and Beaufighter, were (i) the main inter‐spar ribs to which the fuselage is attached, and (ii) the ribs carrying the nacelle structure (FIG. 26). The attachment ribs for the fuselage were usually known as the box ribs, a term derived from their form of construction which consisted of inner and outer alclad webs with top booms of extruded angfe section and built‐up bottom booms of box section forming the link between the longerons of the front and rear fuselages. On the Beaufighter the ribs were attached to the spars by means of extruded angles, extruded channels being employed on the Beaufort (FIG. 27). The ribs were further stiffened by inter‐web members of channel section. Each attachment rib for the nacelle structure consisted of an alclad web with a top and bottom boom of extruded angle section and secured to a bracing of square section steel tubes.