Hawker-Raytheon 4000 HorizonHawker 4000 airplane model. Design work on what became the Horizon was already underway when Raytheon Corporate Jets and Beech merged in early 1995 to form Raytheon Aircraft. The new design, initially labelled PD376 and later Horizon 1000, was one of three projects the new Raytheon Aircraft was working on, along with what became the Premier I. Raytheon worked closely with potential customers for the replacement for the Hawker 1000 in the design