Virtual factory software ensures integrity of redesigned landing gear for jet fighter

Citation

(2002), "Virtual factory software ensures integrity of redesigned landing gear for jet fighter", Aircraft Engineering and Aerospace Technology, Vol. 74 No. 1. https://doi.org/10.1108/aeat.2002.12774aab.015

Virtual factory software ensures integrity of redesigned landing gear for jet fighter

Keywords: Software, Landing gear

Saab-BAE Systems has used the latest assembly planning software from Tecnomatix Technologies to verify the redesigned landing gear and assembly procedure for the Gripen jet fighter. As a result of using Tecnomatixl eM-Workplace software, the company reports that it was able to meet the extremely tight delivery deadline for the project. It explains that it did this by using eM-Workplace to detect potential assembly problems early in the design process, and thus avoided the need to rework some of the designs at a later stage. In addition, the ability to visualise components on PCs on the shopfloor gave the operators a far better insight into the objectives required (Plate 12).

Plate 12 Screenshot from Saab-BAE SYSTEMS' virtual factory based on eM-TolMate, the assembly planning software from Tecnomatix. This is being used at the heart of an award-winning project to ensure the integrity of new designs and streamline the manufacture of the landing gear for the Gripen, one of the most successful new jet fighters in modern times

The Gripen is one of the most successful designs for military aircraft in recent times. A fourth generation swing-role supersonic fighter developed by Saab of Sweden, it incorporates major improvements in reliability and maintainability, allowing for higher sortie rates and lower life cycle costs than previous generations of combat aircraft.

The Gripen is already in front-line service with the Swedish air force, but BAE Systems recognised the export potential for. this aircraft amongst its existing customer base of overseas air forces. A joint venture was set up between the two companies, with the result that, in December 1999, the South African government placed an order for Gripen fighters, including nine fully combat- capable two-seaters. Further discussions are now taking place in a number of countries, including Austria, Brazil, Chile, Poland and the Czech Republic.

As part of the joint venture agreement, BAE Systems now undertakes a proportion of the assembly work for the Gripen. This includes the main landing gear unit, which is assembled at Brough from parts sent over from Saab in Sweden.

The design and construction of the landing gear unit are extremely important because, essentially, the rest of the aircraft is built around it. The designs are often extremely complex, involving large numbers of components and lengthy assembly times. Moreover, a delay in the landing gear assembly can delay construction of the rest of the aircraft. Saab and BAE Systems were therefore anxious to minimise the costs and parts count of the Gripen, and to cut the cycle time for its assembly. They set a target to reduce these by 18 per cent through the use of a completely new build philosophy.

Several key areas of concern were identified. Possibly the most important of these was the need to reduce the number of Query Notes raised after Construction of the landing gear unit had begun, and the consequent delays while problems were investigated.

A Query Note is raised if any problem occurs during the build phase of the landing gear. Each note adds a significant cost to the business. In addition, construction work often has to stop while the issue is investigated, and then any remedial action still needs to be taken after that. In the past, on projects similar in size to the Gripen main landing gear unit assembly, it has not been unusual for fifteen Query Notes to be raised. By avoiding these, significant cost could be saved in administration, not to mention any additional costs involved in putting the problems right, as well as the time lost. These costs would depend on the complexity of the project and the magnitude of the problem encountered, but they could be considerable.

BAE Systems' approach was to use software tools to redesign the main landing gear and optimise the assembly process for the proposed new design. Both Saab and BAE Systems already had extensive experience of the eMPower suite of software from Tecnomatix, a state-of-the-art set of tools for creating virtual factories, simulating assembly procedures and optimising manufacturing processes.

Once the landing gear had been redesigned, a complete set of 3D digital models of all parts and tooling was created using the company's CAD system. The designs were then imported into eM-Workplace. From the remainder of the six-week project, a Saab engineer operated the eM-Workplace software at the Brough site to verify that it would be possible to assemble the redesigned landing gear and achieve the desired savings in time and cost. As a result of this work, all collisions and job stop situations where identified and remedied prior to any work being taken to the shopfloor.

eM-Workplace was also used to create animation's for use as part of the work instructions, as well as for training purposes. Furthermore, it is now being used more widely in manufacturing, typically for estimating how long it will take to complete an assembly. The software is reportedly quicker, easier to use and far less tedious than conventional manual method, time and motion (MTM) techniques. Even more importantly, eM-Workplace is said to allow engineers to study many different scenarios and establish a truly optimised process.

We are informed that as a result of the use of eM-Workplace, the build of the Gripen landing gear was completed on time. The tight deadline specified contractually by Saab was met and late delivery payments were avoided. In addition, there were no added extra costs involved in the redesign. Shop floor managers and staff are said to have welcomed the move to a combination of paper drawings and mpeg animations from the eM-Workplace simulations – the project team described the animations as "an automated Haynes manual for assembly". The ability to visualise components on PCs on the shopfloor gave the operators a far better insight into the objectives required.

When the project was completed, a roadshow was held for people from functions such as design, engineering and manufacturing within BAE Systems to look more closely at eM-Workplace. As a result, Tecnomatix received several suggestions for enhancing the software, at least one of which has now been implemented. This allows text boxes to appear on screen as the cursor is moved over different objects – providing additional information or comments pertinent to those objects.

In addition, the Gripen project was presented at an internal managers' meeting at Brough, following which it was nominated for the BAE Systems Chairman's Award for Innovation. This gives recognition to outstanding technical innovation within the company. The Gripen project received a Bronze Award for the introduction of Tecnomatixl eM-Workplace software, which is now being considered for a Silver Award.

The project was chosen for the award because of the size and complexity of the simulation, the close co-operation between the BAE, Saab and Tecnomatix staff, and the constructive feedback that led to changes being made in the software by Tecnomatix. In addition, marks were awarded for the use of eM- Workplace visualisations for shopfloor training.

Details available from: Tecnomatix Technologies Limited,Tel: +44 (0)121 323 1309; E-mail: kate@tecnomatix.co.uk; Website: www.tecnomatix.com