VALISYS at the leading edge for right-first-time aerostructures

Citation

(1999), "VALISYS at the leading edge for right-first-time aerostructures", Assembly Automation, Vol. 19 No. 2. https://doi.org/10.1108/aa.1999.03319baf.009

VALISYS at the leading edge for right-first-time aerostructures

VALISYS at the leading edge for right-first-time aerostructures

Keywords Aerospace, Tecnomatix

VALISYS, a quality management software tool from Tecnomatix Technologies Limited, is being used by Aerostructures Hamble to support the manufacture of wing leading edge components for Boeing's latest variant of the 737 series airliner (see Plate 8).

The contract has been running for over four years, with deliveries of the 1,000,000th component during 1998 bringing praise from Boeing for "Aerostructures' high level of commitment to the programme and the quality of its work".

Plate 8 Tecnomatix's VALISYS is used by Aerostructures Hamble to manage the measurement of complex wing leading edge components

In addition to breaking new ground in manufacturing processes, the contract involved the measurement of complex components and quality management, using softgauging, feedback and analysis facilities provided by VALISYS software.

VALISYS was implemented as part of a complete overhaul, of the company's computer-aided engineering (CAE) system. This was backed up by the introduction of advanced metrology for contact and optical measurement systems and procedures to achieve "right-first-time" determinant assembly; the use of key characteristics and statistical process control (SPC).

All of the Boeing component designs are based on solid models, produced by CATIA with digital data replacing blueprints as the authority data for product manufacture. Whilst CATIA allows the solid data to be turned into a manufactured product, it does not ensure the quality or conformance of the product from the point of view of inspection, and auditability.

Aerostructures needed to prove that the data, as they were released from Boeing, were virginal and untouched and could be relied on for final acceptance. To do this, Aerostructures upgraded its metrology capability to introduce co-ordinate measuring machines (CMMs), using VALISYS to provide a common quality management environment. Since VALISYS was fully integrated within CATIA this provided backward auditability to the authority model. VALISYS also provided a single common off-line programming facility to support measurement on CMMs, as well as machine tool probing.

The graphical feedback is also an important feature, as it helps to show non-conformity and quality performance in a relatively simplistic way.

Another main strength of VALISYS ­ the analysis of extremely complex technical problems ­ was put to the test when production was almost brought to a standstill by an unusually high rate of non-conforming product.

"Previous inspection techniques had never shown non-conformance because they could not provide a true interpretation of things like geometrical dimensioning and tolerances and datum structures", explains Michael Neave, technical director of the Hamble Group. "Having highlighted the problem we now had to do something positive to fix it. VALISYS showed that we needed to build a clearer understanding of the original design intent. As a tool, VALISYS is only one element in an extremely complex process which relies on a common understanding of the datum structure, the impact of geometrical tolerances and real design intent being communicated directly from the designers, through to the manufacturing engineers and the quality engineers."

The analytical facilities of VALISYS are also being used in the development of tooling and particularly with regard to the production of NC programming. Other benefits include greater flexibility within the CMM type environment. Aerostructures can interchange all of its CMM programmers and operators, between machines and parts. The company has also achieved direct programming productivity improvements estimated at better than 30 per cent.

Michael Neave adds, "The main benefit, however, is in understanding the problems with parts. Aircraft structures are very complex with multiple variables. Previously parts were installed in fixtures and fitted by trimming, or shimming to fit the structure. By using digital measurement and VALISYS to relate the part accurately to the aircraft datum structure, we now have better visibility of any non-conformity of the component and can do something about it."

As a result, all of the parts supplied by Aerostructures to the 737 programme will fit straight out of the box. The component chosen to mark the company's 1,000,000th delivery ­ the in-board strakelet ­ is a typical example of the many cost savings being achieved under Boeing's policy of true determinant assembly.

The strakelet is a complex component which sits between the wing and the fuselage, with a hole in the middle for the landing light. Previously, these components would have been supplied with plus material and special tooling fixtures to aid assembly.

There's virtually no assembly tooling used on the 737 leading edge. Parts are manufactured in a precision detail form and they literally clip together. That has resulted in significant reductions in assembly time. The parts are installed by an automated tool, whereas traditionally this would have been a manual process.

Looking ahead, Michael Neave will also be applying VALISYS at the front end of the design cycle: "We will be making use of the tolerance stack analysis facility in new product design and we believe the gauging features can also be used earlier in the design cycle rather than waiting until the product has been released into manufacturing and inspection. We believe we can use VALISYS to improve the product development in the design development of the product rather than during the inspection process. We believe that this tool has made an important contribution by helping Aerostructures to reduce development costs and delivery timescales on our current programmes."

For further information contact: Eric Gautier, Marketing Manager Europe, Tecnomatix Technologies SA, European Headquarters, Espace Jouy Technology, 21 Rue Albert Calmette, 78350 Jouy en Josas, France. Tel: 00 33 1 3458 2424; Fax: 00 33 1 3458 2442.