Freighter Aircraft

Overview

The Freighter Aircraft is a twin-engine cargo airplane built around a single feature that a passenger conversion cannot match cheaply: a large Main-Deck Cargo Door cut into the side of the upper fuselage, served by a powered Cargo Handling System system that moves palletised freight across a reinforced Cargo Floor. The aircraft carries up to 54,000 kg of payload across 24 main-deck pallet positions and a further 10 in the lower hold, and flies routes of about 4,200 km at maximum load. Everything else, the Airframe, the two Turbofan Engine units, the Landing Gear, and the Avionics, is conventional wide-body practice scaled to carry boxes instead of people.

The design starts from the cargo. A standard 2.44 by 3.18 m pallet sets the door size, the floor strength, and the lock spacing, so the fuselage is sized so that loaded pallets clear the door frame and roll the full length of the deck without a crane. The main deck holds no windows aft of the flight deck and no cabin fit, which saves weight and lets the structure take the heavy point loads a pallet of dense freight puts into the floor.

Airframe and Cargo Floor

The Fuselage is an aluminium semi-monocoque: 90 Fuselage Frame rings, 180 Stringer runs, and Skin Panel sheet riveted into a pressure shell closed at each end by a domed Pressure Bulkhead. The freighter difference sits in the floor. A passenger floor is built for distributed seat loads, but the Cargo Floor takes concentrated loads from pallet corners, so it uses deep Floor Beam members tied into the frames, Cargo Track extrusions running fore and aft to anchor the rollers and locks, and honeycomb Floor Panel sandwich between the tracks.

The Main-Deck Cargo Door is the largest cut-out in the structure. It opens upward and outward on four Door Hinge Arm arms driven by two hydraulic Door Actuator units, swinging the Door Structure clear of a 3.40 by 2.55 m opening. Because the door interrupts the pressure shell, eight Door Latch hooks pull it tight against the frame so it carries hoop load like the surrounding skin, and an inflatable Door Seal keeps the cabin sealed. The opening is reinforced with extra frames and a thicker door surround so the skin does not fatigue around the corners under repeated pressure cycles.

The Wing is a swept two-spar box: Wing Spar members carry the bending load, Wing Rib sections hold the aerofoil shape, and Wing Skin panels close the box and form the walls of the integral fuel tank. High lift comes from a Leading-Edge Slat on each leading edge and a double-slotted Flap on each trailing edge, with roll from the Aileron and lift dumping from the Spoiler panels. The Empennage is a conventional tail with a trimmable Horizontal Stabiliser.

Powerplant

Each Turbofan Engine is a high-bypass two-spool turbofan giving about 120 kN of thrust. Most of the air goes through the Fan and around the core, which is the efficient way to make thrust at cruise. The core squeezes its share through the LP Compressor and HP Compressor, burns it in the Combustor, and extracts work in the HP Turbine and LP Turbine. The high-pressure turbine drives the core compressor, the low-pressure turbine drives the fan, and a FADEC meters fuel and holds the engine inside its limits. On landing a cascade Thrust Reverser deflects fan air forward to help slow the loaded aircraft. The engine hangs from a titanium Engine Pylon under the wing on a fail-safe Engine Mount.

Hydraulics and Flight Controls

The freighter runs three independent 3,000 psi Hydraulic System systems so that the loss of any one leaves the aircraft fully controllable. Each system is fed by an engine-driven Engine-Driven Pump pump, backed by an Electric Pump, with a Hydraulic Reservoir keeping the pump inlet supplied and an Accumulator storing energy for transient demand. If both engines stop, a drop-down Ram Air Turbine turns in the slipstream to keep the most critical surfaces powered.

The Flight Controls are hydraulically powered. The Control Column and Rudder Pedal Set sets command Powered Control Unit actuators on the primary surfaces, each driven by a Servo Valve that ports hydraulic flow to move the surface. The flaps and slats are driven from a central Flap Power Drive Unit and Slat Power Drive Unit so both wings move together, pitch trim comes from the Stabiliser Trim Actuator jackscrew tilting the whole tailplane, and a Yaw Damper suppresses Dutch-roll.

Cargo Handling

The Cargo Handling System system is what lets two ground crew load the aircraft in under an hour. A pallet rolls through the door onto a Ball Transfer Mat, a bed of ball units that lets it turn in any direction, then transfers onto the powered floor. Rows of Powered Drive Unit drive units lift and propel the pallet along the deck, with Roller Tray sections carrying it between drive points. Once a pallet reaches its position, Pallet Lock units rise on each edge to restrain it against flight loads, each holding the pallet with a Lock Pawl backed by a Coil Spring. A Cargo Winch hauls heavy or non-self-propelled loads up the floor, and the whole sequence is run from a Cargo Control Panel panel. A Barrier Net barrier protects the flight deck from any load that shifts forward.

Systems and Use

The Fuel System holds fuel in wing and centre Fuel Tank units, fed by Boost Pump pumps and refilled through a single-point Refuel Panel. The Environmental Control system conditions the deck with engine Bleed Air System cooled by an Air Cycle Machine and held at the right cabin altitude by a Pressure Controller working against an Outflow Valve. The Electrical System system generates AC from two engine Generator units, backed by an Auxiliary Power Unit for ground power and a Battery for emergencies, with each Generator driven through a Helical Gear Pair in its constant-speed drive.

In service the aircraft flies overnight express and scheduled freight networks, carrying mixed e-commerce parcels, mail, perishables, and outsize machinery between hub airports. Operators choose between a higher-payload variant for short dense routes and a longer-range version that trades pallets for fuel, both built on the same airframe, door, and floor so a fleet shares spares and training.