This paper presents a well-rounded description of the development of the de Havilland Trident, from the historical background, through the experimental stages, and finally into the basic model. The design of this aircraft is said to provide “an unrivaled standard of safety, reliability, and serviceability in a vehicle that is fully competitive in speed and operating economy.” The discussion of the design includes such features as configuration, aerodynamic characteristics, structure, control systems, and testing.