The Eurofighter was designed as a multi-role tactical fighter, optimised for Beyond Visual Range (BVR) air combat, but with real air-to-ground capabilities, genuinely deployable, and able to operate from rough, semi-prepared airstrips. The BVR requirement dictated a design with plenty of range and endurance, with a powerful air-to-air radar and the ability to carry a heavy load of long-range missiles, but also with excellent supersonic accleration and agility. These characteristics in turn required the use of advanced materials for structural strength and low weight, powerful afterburning turbofan engines, and a maneouvrable airframe.
Eurofighter is a canard delta design, with the wing leading edge swept at 53 degrees. The swept canard surfaces, which have a marked degree of anhedral, are set well forward in line with the canopy. This provides a high moment arm for optimum control at high alpha, although at the expense of obscuring the view sideways and downwards.
The aircraft is both light and strong because of modern construction techniques. No less than 70% of the surface area is of carbon fibre composite, and a further 12% is glass-reinforced plastic. Most of the rest is metal: titanium is used for the foreplanes, outboard flaperons and structural members, and aluminium-lithium for other parts.
Because the aircraft is a canard, pitch and role are imparted by the foreplanes and the inboard and outboard flaperons, and for this reason they need to be strong. The rudder performs the usual function of yaw control, while the leading-edge slats vary the effective camber of the wing to give the best performance at all angles of attack. As with the F-16, the air intakes are located under the fuselage to ensure a smooth supply of air at low speed and high AOA.
Although low-observability was not the main design driver, it appears that the intention was to reduce head-on RCS to 20-25% that of a conventional fighter. The curved intake ducts are used to mask the engine compressor faces. In addition, tiles (presumably made of a radar-absorbing material) are used to protect reflective internal components, and RAM coats some other areas, such as the wing leading edges.
Eurofighter is the first combat aircraft to be designed with a revolutionary integrated health and usage monitoring system. The system will perform real-time fatigue calculations and will determine the life consumed by the airframe. It will also monitor an aircraft's flight performance and any significant structural damage. The information is gathered at 20 points across the airframe, 16 times a second. In the future the system should be able to identify damage to specific areas of the aircraft as it is inflicted.
The airframe has an intended service life of 6000 hours, or 30 years. Maintainability targets are 10 MMH/FH, and replacement of a single engine by four personnel in 45 minutes. Operational turnround by six groundcrew is expected in 25 minutes.
The Martin-Baker Mk.16A ejection seat is radically different from earlier Martin-Baker designs. Using technology developed in the Mk. 15 seat, the main beam assembly has been replaced by two sets of telescoping tubes which double as the catapult system. A common gas generator provides the force to catapult the seat out of the cockpit. A newly developed underseat rocket system is used for sustained propulsion.
A computer controls sequencing of the seat for effective recovery of the occupant for all expected speed ranges. The seat uses a passive leg restraint system akin to the one used on several Russian seats like the K-36-series. This system consists of a set of restraint lines run around the cockpit leg areas so that the pilot merely places his/her feet on the rudder pedals. These straps are connected to a padded cuff which is stowed on the sides of the seat pan. On ejection the lines are retracted which wraps the cuffs around the lower limbs of the occupant and provides protection against flail injury.
Click here to view the Interactive Cutaway (Opens in new window)
