Poised for an expected launch this month, Airbus' A350 will blend new avionics with tried-and-true systems, incorporating features from both its baseline, the enhanced A330-200, and the all-new A380. While not starting from a blank slate, the two-engine, long-range jet will improve on current A330 avionics performance.
What's more, the added payload range and double-digit economic gains that Airbus expects from the A350's new composite wing, third-generation aluminum alloy fuselage, and quieter, more fuel-efficient engines will spur new customers to give the aircraft a serious look.
Although avionics vendors have not yet been selected, manufacturers of targeted A350 functions who supply the A330, A380 and Boeing 787 will be obvious candidates. The A350 program presently adheres to the Airbus policy of having two suppliers for major avionics systems, says Bruno Ley, deputy chief engineer for A350 systems and avionics.
Evolution in Avionics
The starting point for the A350 is the A330, says Ley, who uses terms like "evolution" and "continuous upgrade" to describe the new aircraft's avionics. The A350's flight deck will look very much like the A330's, and the new airplane will share the same type rating as the earlier model, enabling pilots to transition easily between the two.
The A350 will employ the A330's "classical" avionics architecture, Ley says, rather than the integrated modular avionics architecture that the A380 uses to a certain extent. Nor will the A350 use as its main avionics bus the high-speed, avionics full duplex switched (AFDX) Ethernet data com system designed for the A380. Airbus' newest family member may use AFDX locally with equipment adapted from the A380 and may add video buses, Ley says. But it will use plenty of low-bandwidth ARINC 429 data buses, as well. The flight control system will be adapted from the A330.
The flight management system (FMS) will be based on the A330's equipment, currently produced by Honeywell and Thales. Airbus plans a liquid crystal display (LCD)-based multifunction control display unit (MCDU) for improved brightness and readability. The company expects the FMS to support required navigation performance (RNP) that is better than RNP 0.3 on approach. It is targeting RNP 0.1.
The A380 and A350 will share an FMS landing system (FLS) feature, which presents ILS-like vertical and lateral guidance on the primary flight display, using data from GPS, VOR, DME and inertial reference system. This will enable autonomous non-precision approaches, Airbus says. The A350 also supports precision global navigation satellite system (GNSS) landing system (GLS) approaches, provided that local area augmentation systems are in place.
From the A380, the A350 adapts the air data inertial reference unit, dual integrated standby instruments, and integrated surveillance system (ISS), among other items.
It also adapts a forthcoming A380 feature called "brake to vacate." The system's computer uses algorithms within the autopilot to automatically adjust the aircraft braking so that the pilot can exit the runway at a preselected taxiway. Information displayed on the electronic flight bag's (EFB's) airport moving map helps the pilot maintain situational awareness. Brake to vacate is intended to save wear and tear on the braking system, speed turnaround time, and increase passenger comfort.
The aircraft also will support an "auto pull-up" function, based on the terrain awareness warning system (TAWS). If the pilot does not respond to a TAWS alert, "the autopilot will take the lead and manage the recovery of the situation automatically," Ley explains.
Class III EFBs
Although the A350 won't feature an A380-style cursor control device, its Class III EFBs will be touch-sensitive, displaying airport moving maps, maintenance data and electronic documents. The EFB terminals will be installed in sliding tables directly in front of the pilots, rather than mounted in the flight deck to the far left or right of the cockpit, as in the A380. This configuration is expected to be available on the A330 and 340 next year.
Airbus plans to offer an A380-style ISS, encompassing the weather radar, Mode S surveillance, TAWS and traffic alert collision avoidance system. Honeywell supplies the ISS to the A380, and Rockwell Collins provides a similar architecture for the B787. The A350's 6-by-6-inch nav display will feature a vertical view of weather and terrain.
Airbus will offer basic, single Inmarsat high-speed data satcom (B-GAN/Swift), with provision for dual satcom. It will support the ARINC 781 standard, which allows a smaller hardware footprint.
A350 Avionics Highlights
The A350's avionics are based on the A330 architecture in order to achieve the same type rating. But the new aircraft will leverage A380 technologies, as well. Here are selected highlights:
A330 electronic flight control system (with load alleviation system)
Main displays (6-by-6-inch, video-capable)
A330 flight management system (upgraded)
ARINC 429 data buses
VHF data radios (VDL-2)
Integrated surveillance system (processing):
- Weather radar
- Terrain awareness warning system
- Traffic alert collision avoidance system
- Mode S transponder
Vertical display on nav screen
Air data inertial reference unit
Dual integrated standby instrument system (ISIS),
Dual, LCD-based, head-up displays (optional on A350)
Multimode receiver (supporting GLS/FLS)
Digital radio altimeter
Onboard information terminal (OIT)
FlySmart Class III EFB (with Airbus infrastructure, applications and services)
Brake to vacate function
Airport navigation system