This report describes the conceptual and detail design of the A-90 Short-haul 500 seat airliner project. It started with a market investigation which then lead to the specification of the aircraft. The author performed a conceptual design process, to derive the configuration - a twin-engine jet transport with a swept wing, shoulder mounted to a large double-bubble fuselage. Aerodynamic, mass and geometric work was then performed prior to the start of the main design programme in October 1990. The main programme involved 23 MSc students and 5 members of staff and lasted for 8 months. Each student was given responsibility for the detail design of a major component such as outer wing, fuel system, etc. This work is described together with the final design that emerged. This description is aided by the reproduction of numerous engineering drawings. The work was complemented by extra studies, performed by 15 Flight Dynamics students. The report then discusses the final configuration of the A-90. The project showed the potential of meeting mass, cost and airport requirements. It should exceed the range requirements and carry 620 passengers for 1700 n miles, 500 for 2260 n miles or 345 for 3500 n miles. The design showed considerable flexibility and could be relatively easily developed to carry some 1000 passengers. Investigations were performed of several applications of new technology, including variable camber flaps, fibre optic flight controls, "all electric" systems and modern materials. They all looked feasible, and should be investigated further. The main concern was the provision of bleed air and secondary power following the loss of one engine, on such a large aircraft. Careful system design overcame this problem. The A-90 project proved again the validity of Cranfield's group design project as a powerful means of educating design students.