More than two years before its new twinjet A350 XWB gets airborne, Airbus has worked out the cockpit ergonomics, determined the information the crew needs, how they can access and manipulate it, and how it is to be presented. Now line pilots are testing the interface to enable fine-tuning.

At this stage most of the flightdeck modelling is being done in two spaces. The first is the "A350 XWB aircraft minus one" (A/C -1) cockpit demonstrator, a fixed-base simulator that is not quite a perfect representation of the A350 flightdeck space, but in which the entire interface is virtually the same and functions exactly as it will on the aeroplane.

This is not yet powered by the final avionic suite, but by banks of personal computers. It "flies", and has a first-class external visual system that soon has the handling pilot forgetting the lack of motion. The second is a cockpit mock-up that is a faithful representation of the A350 flightdeck space and its interfaces, but does not function like a simulator. This "class II mock-up" is all about testing the ergonomics of the flightdeck, the lighting, and the visibility of the displays from all angles in all ambient light conditions.

A350 cockpit
 © Airbus
Airbus is preparing to show the world what a fourth-generation flightdeck offers its crew.

The A350 flightdeck has evolved from the A380's, but an A330 pilot would feel totally at home in it. Rather than introducing radical new ideas, the manufacturer has worked on improving the accessibility of the unprecedented amount of information available to the crews, the ease of use of all the avionics and systems, and the clarity and intuitiveness of displays so as to maximise crew situational awareness.

The way flight and systems information is presented to the crew is fundamentally the same as it is in an A330/A340 series aircraft, because although Airbus wants to advance, it also wants to make cross-crew-qualification (CCQ) with other types in its stable easy and cheap.

Easy CCQ means keeping to the minimum the time it takes for an A330 pilot to add an A350 type rating. At present the manufacturer estimates that adding the A350 type rating to an A330 one would involve a 10-day "differences course", but Airbus experimental test pilot Peter Chandler says that is a cautious estimate.

The company's vice-president training Jacques Drappier provides a hint about what the differences between the A330/A340 series and the A350 will feel like to a pilot: "From the piloting point of view the A350 cockpit is quite transparent. Moving forwards [from the A330/A340 to the A350] is always easy. Moving the other way is more difficult."

Most of the differences are in ease of access to information or functions - particularly the flight management system, and flexibility in the choice of where the pilot wants recovered information to be displayed. The FMS display is, relative to those on the A350's forbears, a really big screen - the same size as those for the instrument displays. The display screens are all the same line replaceable unit. As an aside, Chandler reveals that all the FMS improvements being developed for the A350 will be made available in the A380.

A350 Class II cockpit Mock-up at night
 © Airbus

For A350 pilots, sharing information is much easier even than on the A380. For example, either pilot can recover an approach plate from the on-board information system, then transfer it from the screen to one of the centre multifunction displays (MFD) to aid the top-of-descent briefing. Both pilots can "share" the chart in that central position, and reach it easily to point things out.

The A350 has four MFDs: two of them are side by side in the centre of the main panel, and two lie canted upward at an angle at the forward end of the centre pedestal. The left MFD on the main panel would normally display engine and systems information, the right one controller-pilot datalink communications (CPDLC) messages at the top and alert and system warnings below that.

The two lower MFDs would normally display FMS data selected by the individual pilots. Positioned either side of this pair of lower MFDs are (to the left) the standby primary flight display and (right) the standby horizontal situation display, both looking rather little and not ideally placed.

The ease of transferring images around the displays is analogous to handing paper charts or printouts across the cockpit and being able to clip them where the pilots want them. If, during the chart-sharing top-of-descent briefing referred to above, the pilots want to relocate the FMS display away from one of the centre MFDs, they can put it on the on-board information system display and still manipulate it there, either from the individual keyboard cursor control units (KCCU) on the centre pedestal, or the pull-out keyboards on the tray table beneath each pilots' flight displays.

Both are qwerty keyboards with a roller-ball directed cursor, which provides selectable one-click access to a menu of functions, information and checklists. Whereas checklists on the A380 are executed via the electronic centralised aircraft monitor controls, on the A350 they are KCCU-controlled. The only checklists for the A350 not in the system are those for smoke drills and emergency evacuation. For obvious reasons they are in the hard copy quick reference handbook.

The FMS is completely roll-and-click menu-driven, and amendments to the flight plan can be executed either on the FMS or the navigation display by clicking on desired waypoints. The advantage of the tray-table keyboard is that pilots can get both hands to it, which is intuitive for a qwerty keyboard, whereas the KCCUs are usable with one hand only unless the pilots are contortionists.

Although almost all crew acknowledgements for air traffic control CPDLC messages are menu-selectable, if a non-standard reply is required, the keyboard also makes creating it that much easier, as it does for management messages via the aircraft communications addressing and reporting system or VHF datalink (VDL-2).

As Chandler says, the most impressive upgrades from the A380 to the A350 are in the FMS capability, and they will soon be offered in the A380 too. Among these are "escape routes" that are embedded in the FMS. Imagine a crew confronted with an engine shutdown over the Himalayas: the inability to maintain height means the crew need to calculate the safest route to adopt during driftdown, and the rate of driftdown itself.

The A350 FMS, on demand, will automatically calculate the best heading and provide driftdown data. Even worse for the crew would be a sudden depressurisation over high terrain, forcing descent before oxygen runs out. The immediate availability of the safest available escape route would be a potential lifesaver.

But pilots do not have to wait for the actual emergency to prepare themselves mentally for what they would do when it happens. They can ask the FMS "what if" questions and get answers related to specific emergencies such as engine failure or depressurisation at their present position, or from a waypoint ahead. If the pilot also specifies a desired diversion destination, the FMS will automatically perform the flight planning to get the aircraft there.

Another safety function available on the A350 is dubbed "take-off securing". If the pilots enter take-off speeds that do not compute according to weight and balance data in the FMS, the pilots are alerted to check their figures. This is an FMS, not an on-board information system function, says Chandler.

But as for simple inter-pilot communication and crew resource management, the "sharing" quality of the A350 flightdeck is outstanding. Quite apart from the improved crew resource management that flexible use of the displays can offer, the two on-board information system displays can be read easily across the cockpit. They are significantly larger than their counterparts in the A380 and are positioned immediately outboard of each pilot's primary flight display, but because of their size and the fact that they are angled inward, they can easily be read from the other side of the cockpit by the pilot in the opposite seat.

cockpit display
 © Airbus

The on-board information system functions on the A350 are divided into a built-in section integrated with the avionics, and a class II electronic flight bag. The latter is a dockable laptop which can bring on board all the operations and performance data, which would include the "electronic flight folder" information, like notams, weather and loadsheet data.

But in the end, the A350 has what looks like a familiar modern cockpit. The primary flight and navigation displays are exactly where a pilot would expect to see them, if larger than most pilots will have been used to - especially in depth - which makes the vertical flight and terrain profile clearer beneath the navigation display's horizontal display. Dual head-up displays will be an option on the A350, but for those who choose them they will contain all the flight mode annuciators to make them compatible with the head-down displays, says Chandler, who adds that a single head-up display will not be an option.

So the A350's flightdeck offers unprecedented ease of access to data, tremendous flexibility in how to display and share information between the pilots, but also a place of work that feels comfortingly familiar.

Source: Flight International