Airbus A330 - Q&A

Airbus A330: The Airbus A330 is one of the safest aircraft in the sky. There are around 600 of them operating commercially, clocking up millions of flying hours every year.

Despite being introduced more than 11 years ago, the Air France disaster was the first major accident for the wide bodied Airbus. The only other fatal accident happened back in 1994, when a prototype version of the A330-200 crashed during testing, killing the seven people on board.

It comes in two main variants, the A330-200 (which was involved in the accident) and the A330-300, and is well known for being a pioneer of fly by wire technology.

Emirates and Qatar Airways are two of the major customers of the A330, and have been flying the planes safely for several years.

Fly-by-wire: A fly-by-wire system means there are no mechanical link parts connecting the flight deck to the aircraft's control mechanisms (eg: the rudder, wing ailerons or elevators). The pilot's control handle is connected to the internal computer which calculate how to move the control surfaces by actuators (electric or hydraulic motors). The largest criticism of the system is that in the event of a catastrophic failure on A330, there is no manual control back-up. Instead the aircraft has several computers which can act as failsafes in the event of the main computer breaking.

Speed sensor: The parts which are being replaced by Air France are known as speed sensors, or pitot tubes. It is a simple device: a heated metal tube mounted on the outside of the aircraft which faces forward. The faster the plane goes, the more air is “pushed'' into the tube. This pressure is measured by a computer and the aircraft's speed is calculated after corrections are made for air temperature and altitude.There are three or four of these Pitot tubes on every aircraft so they would all have to break at the same time to loose speed information.