A Description of the Design Philosophy as it Applies to Wings, Engine Nacelles, Flaps, Fuselage, Tail Unit, Control Surfaces and Aircraft Performance. The aerodynamic design of the Belfast owes much to the earlier Bristol Britannia although it is an appreciably larger aircraft in all respects. Hence the major components of the Britannia, which have been incorporated in the Belfast and possess a substantial background of practical experience, have entailed little or no development risk in the aerodynamic sense. The principal components which have benefited in the above manner include the wing, tailplane, fin and control surfaces.