Airbus A330 - Design

Design

The A330 is a medium-size, wide-body airliner, with two engines suspended on pylons under the wings. On the ground, the two-wheel nose undercarriage and two four-wheel bogie main legs built by Messier-Dowty support a maximum ramp weight (MRW) of 230.9 tonnes (509,000 lb), while the designed maximum takeoff weight (MTOW) is 230 tonnes (510,000 lb) on the A330-200 variant. An option allows a maximum ramp weight of 233.9 tonnes (516,000 lb) with a maximum takeoff weight of 233.0 tonnes (514,000 lb).

The airframe of the A330 features a low-wing cantilever monoplane with a wing virtually identical to that of the A340. The wings were designed and manufactured by BAe, which developed a long slender wing with a very high aspect ratio to provide high aerodynamic efficiency. The wing is swept back at 30 degrees and, along with other design features, allows a maximum operating Mach number of 0.86. The wing has a very high thickness-to-chord ratio of 12.8 per cent, which means that a long span and high aspect ratio can be attained without a severe weight penalty. For comparison, the rival MD-11 has a thickness-to-chord ratio of 8–9 per cent. Each wing also has a 2.74 m (9.0 ft) tall winglet instead of the wingtip fences found on earlier Airbus aircraft.

The shared wing design with the A340 allowed the A330 to incorporate aerodynamic features developed for the former aircraft. The failure of International Aero Engines' radical ultra-high-bypass V2500 "SuperFan", which had promised around 15 per cent fuel burn reduction for the A340, led to multiple enhancements including wing upgrades to compensate. Originally designed with a 56 m (184 ft) span, the wing was later extended to 58.6 m (192 ft) and finally to 60.3 m (198 ft). At 60.3 m (198 ft), the wingspan is similar to the larger Boeing 747-200 but with 65 per cent of the wing area.

The A330 and A340 fuselage is based on that of the Airbus A300-600, with many common parts, and has the same external and cabin width: 5.64 m (18.5 ft) and 5.28 m (17.3 ft). Allowed seating is 2–2–2 six-abreast in first and business class, and 2–4–2 eight-abreast in economy. The vertical stabiliser and rudder are made mostly of composite materials. On the ground, the A330 uses the Honeywell 331–350C auxiliary power unit (APU).

The A330 shares the same glass cockpit flight deck layout as the A320 and A340, featuring electronic instrument displays rather than mechanical gauges. Instead of a conventional control yoke, the flight deck features side-stick controls, six main displays, and the Electronic Flight Instrument System (EFIS), which covers navigation and flight displays, as well as the Electronic Centralised Aircraft Monitor (ECAM). Apart from the flight deck, the A330 also has the fly-by-wire system common to the A320 family, the A340, the A380, and the upcoming A350. It also features three primary and two secondary flight control systems, as well as a flight envelope limit protection system which prevents maneuvers from exceeding the aircraft's aerodynamic and structural limits.