A design concept of an aircraft family (55 -, 70-, 100-seater) is presented. Started with the reference model of 70-seater, a stretch to 100-seater and shrink to 55-seater is considered ab intio. Impact of commonality in a fleet of different size aircraft is investigated. Passenger comfort, operating aspects and cost are main design drivers. Fly-by-wire flight controls, all-glass cockpit with utility management are applied technologies to end up with an attractive product.