Paris 2011: AgustaWestland asserts its independence in the cockpit
AgustaWestland’s new common cockpit concept is being adopted on all of its new helicopters in order to provide an identical “look and feel” to the operators. But the idea is about more than branding. Ultimately, it’s all to do with safety in the hope that in an emergency situation pilots will not have to give a moment’s thought to which model they are flying since all the commands are identical.
The Italy-based rotorcraft group is looking at a common avionics architecture design that might be adopted both for commercial and military helicopters to keep the product range competitive. The key elements of this are as follows: the cockpit display system, the automatic flight control system and the aircraft management and mission system. The mission system provides dual redundancy for the flight management system, vehicle monitoring system, communications and navigation control system, central maintenance system, digital map and health-and-usage monitoring system.
While the core avionics system hardware is provided by specialist avionics suppliers, the development of flight software and system integration are handled by AgustaWestland’s own avionics team. The thinking here is for the airframer to have plenty of control and flexibility for customizing and modifying the aircraft to customer specifications.
The architecture adopted by AgustaWestland is centered around the AFDX data network developed for the latest commercial airliners. The AFDX high-speed digital bus has been developed to Arinc 664 Part 7 specifications.
This bus is based on improved Ethernet technology. When a message is sent through an Ethernet in current computers there is no certainty that the message has arrived. With AFDX not only does the system confirm that a message has been sent and received, it also includes an integrity check to ensure that it has arrives with all the information intact.
Compared to the Arinc 429-based systems currently used by all commercial helicopters, the AFDX increases the available data bandwidth by a factor of 1,000. On its latest aircraft, AgustaWestland uses a pair of 24-port 100-Mbps switches. The basic avionics suite on these models uses only one tenth of the available bandwidth, which shows the considerable inherent growth potential of the new system.
In the AgustaWestland common architecture, the main external avionics systems linked to the core avionics are the primary flight instruments (ADAHRS, RAD and ALT), the communication and navigation suite (VHF, XPDR and ICS) and the navigation suite (NAV, ADF, DME and GPS). Currently, all these subsystems work on Arinc 429, BUS 1553B or even analog interfaces. With AFDX-interfaced systems, the much faster data rate will allow the transfer of a much more information–a vital factor especially in the military world where transferring high-resolution pictures and streaming video in real time has become important for fully exploiting ISTAR assets. The aircraft’s mission computer will also benefit greatly from the higher data transfer rates.
Another key element in the new AgustaWestland avionics architecture is the Arinc661 capability. This allows cockpit designers to separate the functioning of applications and displays. Commands used purely for the graphical representation of flight data are sent autonomously from an external user application to the cockpit displays.
One benefit from this approach is that when a sensor needs to be replaced, AgustaWestland can simply update the symbology, rather than having to go back to the display manufacturer to have software reworked. This makes any necessary recertification work less complicated and reduces the cost of improving functionality during the life of an aircraft.
AgustaWestand believes the new approach makes it better equipped to initiate improvements in areas such as cockpit displays, mission computers and the autopilot to reduce crew workload and improve aircraft handling. It wants to be able to do this without always having to work through the avionics supplier.
Another objective in terms of cost saving is to increase software commonality between its various models. For instance, the commonality between the AW149 and AW169 helicopters will be between 70 and 90 percent with the new architecture. This is despite the fact that the two cockpits have different numbers of displays–four and three, respectively.