FARO assists Unison in major British Airways reverse engineering application

By Niraj M Wanikar, Chief Editor, CNCTimes.com, 2014-10-16 14:14:36

Scarborough-based Unison Ltd has recently installed a comprehensive tube bending turnkey package at British Airways' Heathrow-based aircraft maintenance, repair and overhaul (MRO) facility. The order included an advanced FARO ScanArm that uses laser and tactile measurement techniques to obtain detailed and highly accurate 3D representations of tubes, enabling precise, rapid reverse engineering. The resulting programmes can then be downloaded to British Airways’ new bending machines within minutes.

The all-inclusive Unison solution, supplied to British Airways for fabricating precision tubular parts, is based on a semi-manual bender with CNC control and a fully CNC all-electric model, both machines are used extensively throughout the global aerospace industry and able to support a wide range of MRO activities.

To help maximise operational efficiency, British Airways maintains its fleet of aircraft in-house. The loss of revenue resulting from the grounding of a modern aircraft can be astronomical, making fast-turnaround MRO capabilities vital to economic performance. Unison's renowned tube bending capability, together with the multiple advantages gained through FARO’s precise measurement and reverse engineering competence will help meet the long-term challenging needs of this vital repair and maintenance workshop.

British Airways has embarked on a major upgrade to its fleet of long-haul aircraft, which is set to include the addition of Boeing 787 Dreamliners and Airbus A380 superjumbos over the next 10 years. The introduction of these latest-generation aircraft poses numerous new challenges for the airline’s repair and maintenance personnel. One area that is receiving particular attention is the fabrication of replacement rigid hydraulic tubes. The central hydraulic systems of Boeing 787 and Airbus A380 aircraft operate at 5,000 psi – most commercial aircraft have 3,000 psi systems – to allow use of smaller and lighter hydraulic components. Much of the interconnecting hydraulic pipework on latest-generation aircraft is manufactured from specialist aerospace materials such as titanium alloy, using thick tube walls to accommodate the high working pressures; a 25 mm hydraulic tube for an aileron actuator, for example, would typically have a wall thickness of 2.5 mm.

Fabricating replacement high-pressure hydraulic tubes from these demanding materials economically, to the very high quality and safety standards demanded by the aerospace industry, requires the use of high precision bending and measurement equipment, backed by in-depth application-specific knowledge. Following the decision to upgrade the tube fabrication capabilities of its repair and maintenance workshop, British Airways searched for a tube bending machine manufacturing company with proven expertise within the aerospace sector. Unison was an obvious contender; the company’s all-electric tube bending technology is used by a number of leading aerospace manufacturers, including Boeing and Airbus, to produce parts for engines and airframes. In fact, Unison machines are already used to produce hydraulic fluid lines for both the 787 Dreamliner and A380.

For the British Airways application, Unison configured a complete measure/program/manufacture turnkey MRO package for tubular components. This approach will enable a quick and cost-effective repair of fluid lines on aircraft by reverse engineering OEM parts and then accurately re-creating them in the workshop. The package covers tube sizes from a few millimetres up to 40 mm in diameter and accommodates the variety of materials used in this application, including stainless steel and titanium alloy.

For demanding bending tasks, such as rotary draw bending of thick-walled titanium alloy or large diameter tubes, the package includes a single-stack 40 mm machine from Unison’s Breeze range of all-electric tube benders. This machine is also equipped with Unison’s unique laser-controlled springback measurement and correction. The system ensures bending precision by automatically compensating for the natural tendency of metal tubes to spring back slightly after being bent, eliminating expensive scrap by facilitating right-first-time results.

For cost effective bending of intricate stainless steel tube parts with smaller diameters up to 30 mm, Unison is supplying British Airways with an EvBend 1000 machine. Capable of extremely accurate left and right hand bending, this CNC controlled manually powered machine is a popular choice with metal fabricators for precision low-volume work, such as aerospace parts manufacture. Originally developed by a specialist tube manipulation company, Silkmead Tubular, EvBend 1000 machines are now manufactured by Unison in Scarborough.

If a suitable CAD file for the tubular part is available, tube fabrication data can be extracted and downloaded direct to the appropriate bending machine. However, a more likely scenario is that, at least in the first instance, there will be no supporting design data for a tube that needs replacing. In this instance, after removing the worn or damaged part from the aircraft, maintenance personnel will obtain the tube’s physical measurements using the FARO ScanArm and then process the information to create a suitable bending programme.

Under the terms of the order from British Airways, in addition to supplying the complete turnkey tube fabrication solution, Unison is responsible for all aspects of bending machine integration and associated equipment connectivity. As Unison’s Managing Director, Mr Alan Pickering, points out, “This turnkey solution demands tight integration of hardware and software resources to create a seamless production environment for efficient on-demand manufacture of specialist precision parts.

“As FARO is a global leader within the field of portable, precise measurement and is a trusted Unison ‘partner’, we were delighted to include the company’s advanced ScanArm and software as part of this turnkey package. The synergy between the ScanArm’s excellent reverse engineering capability and Unison’s advanced tube bending machines, results in the perfect all-inclusive package.

“By assigning responsibility for the performance of the entire installation to Unison, British Airways can be confident that its tube fabrication requirements are fully met from the outset.”

Non-contact measurement devices are becoming increasingly popular. Handheld laser scanners provide a quick and effective way to inspect and reverse engineer complex parts and surfaces. The advanced, highly accurate technology is able to quickly translate everyday objects into digital computer models. Soft, deformable and complex shapes can be easily inspected – without the equipment user ever coming into contact with the measured part.

Throughout the world, industries such as the aerospace, power generation, automotive, metal fabrication and tool & die manufacturing sectors use the FARO products for rapid non-contact inspection and reverse engineering tasks. The ScanArm’s range of applications includes CAD-based inspection, rapid prototyping and first article inspection. Portable CMMs from FARO simplify the implementation of geometric dimensioning and tolerancing (GD&T) and provide efficient, easy-to-use solutions for CAD-based 3D inspections and nominal comparisons.

The advanced FARO ScanArm, as supplied by Unison, combines all of the advantages associated with the globally popular FaroArm, with the benefits of an accurate, hand-held laser scanner. This inventive arrangement provides the perfect contact/non-contact measurement combination. Unlike other scanning systems, the ScanArm’s hard probe and the Laser Line Probe are able to digitise interchangeably without having to remove either component. Users can accurately measure prismatic features with the hard probe, then laser scan sections requiring larger volumes of data with one simple tool.

With versatile contact and non-contact measuring capabilities, the innovative ScanArm is ideal for performing rapid reverse engineering tasks. In addition, the popular FARO instrument can utilise CAD overlays to check complex geometries against design or CAD comparison and evaluate deviations in surface form, ensuring that all inspected parts are manufactured to exacting tolerances.

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