Issue: Volume: 25 Issue: 4 (April 2002)

The Main Route

Engineers virtually configure and test routing designs for the new Airbus

By Katherine Tyrka

When it takes to the sky in 2004, the new Airbus A380 from Airbus SAS (Toulouse, France) will be the most spacious commercial passenger aircraft ever built, measuring 80 meters from nose to tail and from nose to wing tip. Despite the plane's enormous size, the space allocated to routing the aircraft's critical internal systems is more constrained than ever.

Conserving space for the fuel, electrical, oxygen, and other systems was the key to accommodating 555 passengers in a three-class interior layout, compared to the smaller 75-meter A340-600, which seats 380. To meet this design demand, Airbus engineers are using a 3D virtual environment called IRIS, a acronym for the French translation of Interactive System Implantation and Routing, to conceptualize and analyze these systems during the airplane's initial development phase.

The design software, created by the EADS (European Aeronautic Defense and Space company) Corporate Common Re search Center (CCR), enables architects to quickly explore different configurations for the 11 systems that snake throughout the plane, and later output the data to a CAD program. The application does not require a tremendous amount of computer memory, so it can function on a PC or workstation. Furthermore, users do not need previous CAD experience, because the program was designed for engineers who are accustomed to working with 2D drawings.

"Most of our system engineers do not use CAD programs, so we needed an easy-to-use ap plication that would allow them to rapidly predesign, visualize, and analyze all systems throughout the airplane," says Christophe Brosse, head of systems lay out integration for the Airbus. "IRIS is like [Micro soft's] PowerPoint, only in 3D. All the systems can be created, viewed, and modified. Then, once the routings are validated, the data can be exported directly to the airplane's structural architecture within the CAD program."
Engineers used the IRIS virtual environment (above) to configure an optimal routing plan for the internal systems that snake through the new Airbus. They also analyzed engine explosions (shown at right in red) to determine which areas to avoid when routi

The CCR development team based the application on the Sense8 WorldToolKit from EAI (now UGS), a library of virtual reality functions for building, manipulating, and navigating data within a 3D environment. The IRIS data can be exported in VRML format for browser viewing, or directly into PTC's CADDS 5i CAD/CAM suite, which is primarily used for the Air bus's overall structure development, along with Dassault Systemes' Catia.

Once the basic structure of the airplane is imported into the IRIS VRML-based environment, each engineering team creates an initial routing design for its particular system. During this process, collisions and interferences are checked interactively.

"There are minimal distances that must be maintained among certain systems," explains Nicolas Chevassus, IRIS project manager at the CCR. "Electrical interference is one issue, but also of concern are safety measures such as keeping fuel and oxygen systems at a required distance from the electrical lines."

Within IRIS, the engineers can also perform risk simulation and analysis as required under strict European guidelines for airplane certification. For instance, the group can simulate tire and engine explosions to ensure that redundant systems remain intact under the harshest conditions. Performing this kind of analysis much earlier in the design cycle is saving on costly retrofitting downstream.

The application provides other advantages, such as transforming the previously 2D paper designs into reusable 3D data. The collaborative work between system engineers also means that various routing possibilities can be explored to find the most effective solution in terms of space allocation, safety, performance, and cost.
Although the new Airbus A380 will be the world's largest passenger aircraft, the space allocated for the plane's critical systems, which includes a plethora of cables and associated equipment (which appear as colored boxes in this image) is extrem

The CCR is continuing to develop IRIS to enable peer-to-peer, real-time collaboration for on-site or remote meetings among the different system architects. Future functionality will include the ability to couple IRIS to a simulation framework for early validation of system performance. Today, each system can have particular routing rules integrated into the application, such as required distances between different types of electrical systems. And Chevassus hopes to add the ability to export geometric and spatial features to other simulation applications. This would mean that the hydraulic system, for instance, could be exported to a flow analysis program, where the piping diameter and diaphragm position could be analyzed.

Real-time collaboration would also be valuable, Chevassus says, given that the Airbus development takes place in four different countries. IRIS was initially prototyped at EADS Airbus France in July 1999, but is now deployed throughout the Airbus SAS company structure in Germany, England, and Spain.

Although similar software applications are available on the market, Chevassus contends they are either designed for trained CAD users or are simple viewers. This prompted EADS to make the latest version of the program, IRIS 2000, available commercially through CIMPA, a software publishing subsidiary of EADS. CIMPA is also developing other CAD interfaces for the application, so it can be used for any large development project, such as shipbuilding and train design.

Until then, for Airbus SAS at least, IRIS has provided the most direct route for its airplane design.

Key Tool: IRIS, EADS Corporate Common Research Center (

Katherine Tyrka is a freelance writer based at the GEID Press Agency in Paris. She can be reached at