http://en.wikipedia.org/wiki/Airbus_A380






Avionics architecture
The A380 employs an Integrated Modular Avionics (IMA) architecture,
first used in advanced military aircraft such as the F-22 Raptor and
the Eurofighter Typhoon. It is based on a commercial off-the-shelf
(COTS) design. Many previous dedicated single-purpose avionics
computers are replaced by dedicated software housed in onboard
processor modules and servers. This cuts the number of parts, provides
increased flexibility without resorting to customised avionics, and
reduces costs by using commercially available computing power.[25]

Together with IMA, the A380 avionics are very highly networked. The
data communication networks use Avionics Full-Duplex Switched Ethernet,
following the ARINC 664 standard. The data networks are switched
full-duplexed star-topology and based on 100baseTX fast-Ethernet. This
reduces the amount of wiring required and minimizes latency. [29]

The Network Systems Server (NSS) is the heart of A380 paperless
cockpit. It eliminates the bulky manuals and charts traditionally
carried by the pilots. The NSS has enough inbuilt robustness to do away
with onboard backup paper documents. The A380's network and server
system stores data and offers electronic documentation, providing a
required equipment list, navigation charts, performance calculations,
and an aircraft logbook. All are accessible to the pilot from two
additional 27 cm (11 inch) diagonal LCDs, each controlled by its own
keyboard and control cursor device mounted in the foldable table in
front of each pilot.[29]


[edit] Systems
Power-by-wire flight control actuators are used for the first time in
civil service, backing up the primary hydraulic flight control
actuators. During certain manoeuvres, they augment the primary
actuators. They have self-contained hydraulic and electrical power
supplies. They are used as electro-hydrostatic actuators (EHA) in the
aileron and elevator, and as electrical backup hydrostatic actuators
(EBHA) for the rudder and some spoilers.[30]

The aircraft's 350 bar (35 MPa or 5,000 psi) hydraulic system is an
improvement over the typical 210 bar (21 MPa or 3,000 psi) system found
in other commercial aircraft since the 1940s. First used in military
aircraft, higher pressure hydraulics reduce the size of pipelines,
actuators and other components for overall weight reduction. The 350
bar pressure is generated by eight de-clutchable hydraulic pumps.
Pipelines are typically made from titanium and the system features both
fuel and air-cooled heat exchangers. The hydraulics system architecture
also differs significantly from other airliners. Self-contained
electrically powered hydraulic power packs, instead of a secondary
hydraulic system, are the backups for the primary systems. This saves
weight and reduces maintenance.

The A380 uses four 150 kVA variable-frequency electrical generators
eliminating the constant speed drives for better reliability. The A380
uses aluminium power cables instead of copper for greater weight
savings due to the number of cables used for an aircraft of this size
and complexity. The electrical power system is fully computerized and
many contactors and breakers have been replaced by solid-state devices
for better performance and increased reliability.[30]

The A380 features a bulbless illumination system. LEDs are employed in
the cabin, cockpit, cargo and other fuselage areas. The cabin lighting
features programmable multi-spectral LEDs capable of creating a cabin
ambience simulating daylight, night or shades in between. On the
outside of the aircraft, HID lighting is used to give brighter, whiter
and better quality illumination. These two technologies provide
brightness and a service life superior to traditional incandescent
light bulbs.

The A380 was initially planned without thrust reversers, as Airbus
believed it to have ample braking capacity. The FAA disagreed, and
Airbus elected to fit only the two inboard engines with them. The two
outboard engines do not have reversers, reducing the amount of debris
blown up during landing. The A380 features electrically actuated thrust
reversers, giving them better reliability than their pneumatic or
hydraulic equivalents, in addition to saving weight.