The Hawker 4,000 was originally named the Hawker Horizon. It is a super-mid-size corporate jet. Design work on what was originally called the Horizon was already underway when Raytheon Corporate Jets and Beech merged in early 1995 to form Raytheon aircraft. The new design, initially labeled PD376, 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 in the design definition stage and their input directly influenced the direction of the new aircraft.
One of the design philosophies in developing the Hawker 4,000 is to combine the earlier Hawker's popular characteristics with advanced technologies. Experienced Hawker designers formed the core of the Horizon's design team and the aircraft has been deliberately designed to look and feel like a Hawker.
The Horizon features an all-composite fuselage, which is manufactured using the automated fiber placement technology developed for the Premier I. The composite fuselage saves weight and increases cabin volume. The empennage features an aluminum substructure and carbon fiber skin.
Power comes from two digitally controlled Pratt & Whitney Canada PW308A turbofans. P&WC is a risk-sharing partner in the program, as is avionics integrator Honeywell (the Horizon features Honeywell's Primus Epic avionics suite with five flat-panel color LCDs).