Business Jet

Overview

A super-midsize business jet carries eight to ten passengers about 5,900 km, coast-to-coast across the United States or London to the Gulf, at Mach 0.80–0.83, cruising at altitudes up to 45,000 ft where airline traffic thins out. The configuration is the classic executive-jet layout: a clean swept Wing mounted low and carried through beneath the cabin floor, two turbofans on aft fuselage pylons, and a T-Tail Empennage in T-tail arrangement that keeps the horizontal stabiliser out of both the wing wake and the engine exhaust. It is certified to the same FAA Part 25 transport-category standard as an airliner, not to the lighter general-aviation rules.

Airframe

The Fuselage is a conventional aluminium semi-monocoque: chem-milled Skin Panel sections over Fuselage Frame rings, closed by domed Pressure Bulkhead ends. The structure is sized for a 9.6 psi pressure differential, higher than most airliners, which is what holds the cabin near 7,500 ft equivalent altitude while cruising at 45,000 ft. Passengers board through an Airstair Door whose integral folding stairs make the aircraft self-sufficient at airports without ground equipment, and twelve oversized Cabin Window units light the cabin.

The wing is built around two machined Wing Spar members running tip to tip; the sealed box between them is the integral fuel tank, holding roughly 6,700 kg. The aerofoil is supercritical, delaying drag rise so the aircraft cruises efficiently at Mach 0.80. High-lift comes from four Leading-Edge Slat segments and four Fowler Fowler Flap panels; roll control combines Aileron surfaces with Spoiler Panel panels that also serve as speed brakes and lift dumpers after touchdown. Canted Winglet tips trim induced drag on long-range climbs to altitude. The T-tail carries a trimmable Horizontal Stabilizer driven by a Ball Screw actuator at the tip of the Vertical Stabilizer, with conventional Elevator and Rudder surfaces.

Propulsion

Each Turbofan Engine is a medium-bypass turbofan in the 33 kN class, a Fan Module with a bypass ratio near 4.4:1, an HP Compressor using four axial stages plus a centrifugal final stage (a layout typical of this thrust class, where a centrifugal stage is more efficient than tiny axial blading), an annular Combustor and a five-stage Turbine Module. A dual-channel FADEC gives the engine full-authority digital control with no mechanical backup, handling start sequencing, limit protection and thrust setting. Mounting the engines on the aft fuselage keeps the wing clean, shortens the landing gear, and moves noise behind the cabin; the cost is structure to carry engine loads into the rear fuselage and the T-tail it forces. Target-door Thrust Reverser units shorten the landing roll, and a tailcone Auxiliary Power Unit supplies electrics and air conditioning on the ramp through its APU Generator, so the cabin is cool before engine start.

Systems

The Landing Gear is a retractable tricycle. Each leg rides on an Oleo Strut, with the main legs in trailing-link geometry, the arrangement that produces the soft touchdowns owners expect, and Carbon Brake units whose anti-skid control reads Hall Sensor wheel-speed signals. Hydraulic Gear Actuator units retract the gear with mechanical downlocks. The Environmental Control System conditions engine bleed air through Heat Exchanger precoolers and an Air Cycle Machine, with an electronically scheduled Outflow Valve managing cabin pressure automatically through climb and descent.

The Avionics Suite flight deck is built around four large Flight Display touchscreens, dual Flight Management System computers flying RNP arrivals, dual ADAHRS reference units replacing the spinning gyros of earlier generations, and a three-axis Autopilot with autothrottle. An emergency descent mode is standard at these altitudes: if cabin pressure is lost at 45,000 ft, the autopilot rolls the aircraft into a descent to 15,000 ft without pilot input, because time of useful consciousness up there is under 20 seconds. The aircraft is certified for two-pilot operation.

Cabin

The selling point of the super-midsize class is a flat-floor, stand-up Cabin Interior, 1.85 m of headroom over a 7.7 m length, reached without stooping. The typical layout is double-club: eight tracking, swivelling Seat Assembly chairs in facing pairs. A forward Galley with coffee maker and compressor-driven cooler, and an aft enclosed Lavatory with an externally serviced vacuum toilet, bracket the seating. The Cabin Management System system puts lighting, electric window shades, temperature and entertainment on touchscreens and phones, with audio through eight cabin Speaker units. Acoustic treatment in the sidewall lining holds cruise noise near 52 dB, quiet enough for conversation at normal volume, which, along with the schedule freedom, is what the aircraft is actually for.