The stairway to the office area at the front of BAE System's new titanium machining facility at Samlesbury for the F-35 Lightning II has the message: 'The world's largest defence programme' painted on the walls of the stairwell. And that is the backdrop for this leading edge technology facility. The US-led, international participation fifth generation stealth fighter programme is unlike anything that has gone before. Over a span of 25-30 years, around 3,000 fighter aircraft are expected to be produced (see extended online feature for programme detail).
Image: An F-35 under test, flying out of US Air Force base Eglin
As a tier one partner in the programme, BAE Systems has a minimum 10% workshare in the programme, bringing key areas of expertise in the programme, including manufacturing and assembling the aft fuselage, as well as making horizontal and vertical tail fins (collectively, the empennage). In the case of the aft fuselage, BAE is the only company worldwide that supplies this to lead partner Lockheed Martin. In the case of the tail fins, it does, however, subcontract about 20% of its workshare to Australia, Canada and Denmark. And with the Samlesbury facility dedicated to high precision finish machining (0.007 inch tolerances required), rough machining of the raw Beta Annealed Ti-6Al-4V forgings is outsourced to subcontractors in the UK, US and Germany.
The machining facility will make all the aft fuselage components, and some of the vertical and horizontal tail fins for the F-35. The aft fuselage is assembled in a nearby assembly hall and then supplied to Lockheed Martin in Fort Worth, Texas, which assembles the aircraft. Horizontal and vertical tail fins are also supplied to Lockheed Martin, but not as part of any assembly.
It should be understood that, unlike other military programmes, there is no offset element – an agreed workshare based upon the purchase by a country of a certain numbers of aircraft, for example. That means that work is won on a commercial basis, with BAE Systems currently bidding annually - although this will move to multi-year bidding in the future, starting with Lot 9 (see extended article). The drive for ever greater efficiency is, therefore, paramount, as will be seen.
The 9,000 sq m titanium part machining facility – known as building 610 - came on stream last year (JSF parts previously being made on site elsewhere). In fact, first cut took place at 2 pm on the allotted day in August last year, precisely as was scheduled in July 2007, highlights Simon Bee, F-35 head of machining operations. This pin-point timing alludes to a level of detailed planning to which the finished facility itself gives little clue. The only evidence of this planning, apart from a working facility system delivered on time, is up in the offices, where planning matrices and the like still pepper various walls, while the many computer simulations used to model different manufacturing solutions are out of site, held within IT systems. Similarly, the discussions about facility location, layout and design are now history. Indeed, the quiet, unhurried efficiency of the machining set-up, which has even won praise from within the US House of Congress, belies the amount of effort that went before.
Image: Building 610, as the new facility is known at Samlesbury
Image: The first of the two StarragHeckert FMSs
Image: Inside the FMS – cutting in progress
The project that led to building 610 kicked off in 2006, with the first sod cut in May 2009. The BAE Systems' team had a blank sheet of paper on which to plan the new machining hall - something that F-35 programme manager Jon Warburton, responsible for the F-35 investment here and across the Samlesbury site, said made its planning more of a challenge than had there been constraints. Indeed, the project demanded a certain mindset from those individuals within the team, he offers, and the team was hand-picked to support that.
The operation has been designed to support the one-aircraft-a-day assembly requirement, currently planned to start in 2016 and when the facility will be run 24 hours/day, six days a week. At the moment, the cycle is one every eight days, down from one every 15 days, as at the middle of last year, with 20 operatives manning the facility – a further eight to 10 will join them this year.
PRODUCTION ON THE DOUBLE
There will be some 59 different part numbers processed by two, eight-machine FMSs, plus supporting technology (see extended feature) at full tilt. For now, the first FMS is in, bar one final machine, and, therefore running at around 25% capacity, with 20-odd part numbers currently being processed. Two FMSs will be required because TAKT time is longer than one day. Part cycle times vary from eight to 16 hours per stage, with three to four stages per part, while the most complex part requires up to circa 150 tools
As at Machinery's early April visit, there was a large area of clear space between the current FMS and the office area at the front of the building, ready for the second FMS's arrival, which commences in August this year, with the system in production in June 2012. And in 2014, there's likely to be a further 4,000 sq m expansion of the machining facility, which will see the addition of a further eight machines.
The FMSs in the current building will each comprise eight StarragHeckert STC1250 horizontal machining centres (01844 296575). They are standard machines, except for an extended Y-axis, from 1.2 m to 1.9 m. Each has an 80-tool magazine and is managed by Fastems software (driven by Baan ERP) and served by a Fastems pallet system (01322 282276). There are two 7.5 tonne capacity load/unload stations, designed with the help of those that will use them, explains Mr Bee.
This sort of operator engagement is intended to engender a more inclusive culture and sense of ownership. Operators are also involved in day-to-day machine 'good to go' checks, too, for example. This new culture is absolutely essential, if the required cost-down targets of 3-5% per year are to be achieved, he adds
The FMSs are served by a fully enclosed tool store, boasting two Fanuc six-axis robots that pass tools from an adjacent tool store (500 positions per robot) to a gantry robot that subsequently takes these to machines. Uniquely, and developed for BAE Systems, explains Mr Warburton, is the capability for the Fastems' FMS management system to be able to make use of 'remainder' tool life.
Image: An automated tool store serves the FMSs
"If a tool has, say, a life of 30 minutes and 10 of those are used by one machine in the course of its work, the system can look ahead in the schedule to see if another machine can make use of the remaining tool life, rather than break the tool down and throw away the part-used tips, as might have previously been the case.," he points out.
"It takes away any responsibility from the operator, who might play safe on the basis that the parts going through this system are worth many tens of thousands of pounds and a wrong decision would have costly consequences."
TOOLING BILL BOMBSHELL
Avoidance of such negative consequences aside, the system maximises tool life. And, as Mr Bee points out, "simulations indicate that the tooling bill for running the system in support of the one-aircraft-a-day regime will amount to circa £4 to 5 million/year", so it's not hard to see the benefit on that side. Other initiatives are also aimed at reducing this bill (see later).
Based on its tool requirements/tool life calculations, the Fastems cell management system drives the tool presetting department's work-to list, overseen locally by Walter TDM tool management software (01527 839450). Tools that do require dismantling, tip replacement and reassembly are placed by the robots in trolleys, with the trolleys collected by operatives and taken to the presetting area.
Once preset, using Kelch technology (01604 583800) and with offset data and tool life written to Balluff chips (0161 282 4700) on the toolholders, the tools are placed in trolleys, and wheeled back and inserted through the side wall of the robot tool loading enclosure. Incidentally, the presetting and machine load/unload teams rotate, again to provide greater involvement, highlights Mr Bee.
Image: Tools are preset in a separate area, using Kelch technology, and then transported to the automated tool store
The actual shopfloor, apart from the machinery standing upon it, is uncluttered, while the clear area for the second FMS is just that: clear. And that's because all services are above in the ceiling space, accessed by raised walkways, with services 'dropped' as required. From a health and safety point of view, it means there are no additional trip hazards, for example, while it also supports flexibility of plant layout.
Flexibility and future proofing were considerations from the outset, as the facility project commenced prior to the production requirement being known, explains Mr Warburton. So, in addition to the overhead services, the foundations for the machines are generic slabs, with a machine tool requirement being that they had to be floor-mounted and not require specific foundations.
Among the overhead services is a novel overhead swarf extraction, another first achieved by BAE Systems here, although the company has done something similar for aluminium swarf. In fact, a number of suppliers approached did not want to take on the challenge, being concerned about titanium's abrasive nature, explains the F-35 programme manager. Nederman (08452 743434) took on the task, however, and the system sees swarf extracted from machines; passed through an auger, to make sure there are no large objects - broken tools, perhaps - before being transported, under vacuum, upwards through pipes to, first, a centrifuge (reducing moisture content to a maximum of 3%) and then to a swarf skip external to the building at the rear. The weight of swarf discharged is also automatically monitored.
The potential issue of wear in the tubing at corners has been solved by installing sacrificial elements that are replaceable. The system also has a main and a standby pump to make sure there's no stoppage due to lack of swarf disposal, although there's a local 1-2 hour capacity for swarf accumulation.
Alongside the FMS is also a centralised Mayfran self-adjusting coolant system (01204 366469), which sees coolant tested automatically, with de-ionised water (made on site by a reverse-osmosis system) or neat coolant added, as required.
Two further key developments centred on the FMSs are the introduction of robot deburring as part of the second FMS (rolled back to the first), and the introduction of Siemens' ePS condition monitoring system to the FMSs, currently undergoing trial on two machines. But a major push is on to optimise manufacturing processes before they get 'sealed' for production, including the introduction of cutter compensation capability via CATIA V5 and Siemens 840D CNC, which will allow tooling to be reground, and so potentially cut that £4-5 million tooling bill by a third.
After that big hit, it'll be incremental change for this highest of high tech plants, with that supported by BAE Systems' membership of the world-class AMRC at Sheffield, which drives production process innovation and development.
While the two FMSs take pride of place in the facility, there is additional support technology. Most impressive are two StarragHeckert machines of unique design intended to support the manufacture of parts up to 3 m long for the F-35, but which have potential outside of this. The so-called BTP 5000 machines (colloquially, long spar longeron machines) are horizontal, twin-spindle units, with the 1,000 Nm-plus, 8,000 rpm spindles mounted one above the other at 500 mm centres, with each boasting A and C axes. Axis movements are 5, 3 and 2.5 m in X, Y and Z, respectively. One of the machine is integrated into the Fastems system, in terms of tooling management and workload.
Discussions about these machines kicked off in October 2006, in fact, and they will enter the productionisation phase in June this year (2011), with full production set for September. The BTP 5000 is currently exclusive to BAE Systems, with the IPR held by BAE, although the design may become available to other companies in the future.
Also integrated within the FMS is a StarragHeckert CNC horizontal boring machine, HEC 1000 Athletic. This undertakes any post-surface finishing boring. It makes use of Rigibore's novel RF-adjusted boring heads (01736 755355) to position cutting edges based on initial bore measurements. Some 90% of boring is actually undertaken by the FMS horizontal machining centres, the remainder by this borer. Once again, it was not a straightforward selection, different production approaches, such as manual borers, were computer modelled before any choice was firmed up.
Adjacent to the current FMS, at the opposite end to the robotic tool loading system, is the inspection room. Another first for BAE Systems is the use of vertical carousel storage systems, from Kardex (0870 242 2224), to store CMM fixturing. This avoids the requirement to 'soak' fixtures prior to their use, as has been the norm where fixturing had to be held outside the temperature-controlled inspection area. All parts are measured in normal flying attitude, incidentally.
Behind the inspection room, towards the rear of the building is the manual deburring room. Specific values for radii or chamfers are required, with these of critical importance. With most parts requiring painting, lack of attention to obtaining the correct break-edge could lead to poor coating - which could lead to corrosion, while sharp edges are also stress risers. Both reduce in-service life.
The majority of deburring will be integrated into the FMSs in the future, undertaken by robots. Because parts 'move' when removed from their machining fixtures, automated deburring prior to release from fixtures means part features are in a known position.
In keeping with the inclusive culture, the deburring department's specialist will be involved in delivering this automated process.
Box 1 -F-35 Lightning II/Joint Strike Fighter overview
Box 2 -Building 610 facts
Box item 1
F-35 Lightning II/Joint Strike Fighter overview
The F-35 Lightning II, also known as the Joint Strike Fighter, comes in three variants: conventional take-off and landing – CTOL (F-35A); Short Take-Off Vertical Landing – STOVL (F-35B); and a carrier variant - CV (F-35C). F-35s are expected to enter service in 2016 in the US; 2017 in the UK.
Image: The F-35 in flight, there are three variants, although the STOVL project is currently 'on probation', while the UK has cancelled its requirement for this, replacing it with carrier variants
A US-led programme, JSF is described by the US Department of Defense as its "focal point for defining affordable next-generation strike aircraft weapons systems for the Navy, Air Force, Marines and our allies". It further adds: "The JSF's advanced airframe, autonomic logistics, avionics, propulsion systems, stealth and firepower will ensure that the F-35 is the most affordable, lethal, supportable and survivable aircraft ever to be used by so many war fighters across the globe." In shorthand, JSF is a fifth generation stealth fighter.
Initially there was talk of partner nations taking 3,000 aircraft over a 30-or-more-year period, with as many as 6,000 seen demanded by some in total. But latest predictions are more modest, with www.globalsecurity.com putting the total figure at between 2,000 and 3,000, while according to www.forecastinternational.com, there is currently a requirement of 2,443 aircraft from all partner nations, but it accepts that this will fall. There are eight partner nations: the UK, Italy, Australia, Turkey, the Netherlands, Canada, Denmark and Norway.
JSF initially had a target unit price of $29 million-$34 million, but this rose to around $40 million. The actual price of each aircraft has since risen, with the average cost of each one having doubled to $92 million, says www.globalsecurity.com. But according to US budget data for 2010, fly-away cost, which includes the cost of production and production tools, but not research and development, support equipment, or spares, will be between $89 million to $200 million per aircraft. However, lead partner Lockheed Martin says the 'recurring cost' will fall to something like $60 million in 2010 dollars, according to www.forecastinternational.com.
Based on initial work, the JSF programme was given the full go-ahead in the US on 26 October, 2001, with Lockheed Martin teamed with Northrop Grumman and the UK's BAE selected to develop and then produce the Joint Strike Fighter (JSF) aircraft. This signalled the start of the System Development and Demonstration (SDD) phase and, according to the MOD website, the SDD contract's overall value is some $41 billion, to which the UK (the country, not companies) is contributing $2 billion, according to MOD information, but which is put at $2.5 billion by others.
The SDD kicked off the production of an initial 21 aircraft (15 flying test aircraft and six ground-test aircraft, according to BAE Systems). Overlapping the SDD phase are a number of production lots that have been/are being produced, with this element called Low Rate Initial Production, LRIP. LRIP lot 5 discussions are ongoing in the US. The preceding LRIP 4 was to have been for 31 aircraft - 10 F-35A for the US Air Force, 16 F-35B for the US Marine Corps, four F-35C US Navy and one F-35B for the UK, for example, but numbers will change, due to F-35B issues (see later). To give an idea of the worth of such contracts, LRIP 4 was said to be worth $3.9 billion to Lockheed Martin (LRIPs 1-3 were for 31 all together, incidentally). Some 519 aircraft were originally to have been built during the seven LRIP stages, but the final figure will be lower than that.
SDD/LRIP ends in 2016, with the aircraft entering service, and when full rate production is expected to start – that's the manufacture of one aircraft every day, or 220 over a year.
The UK F-35 Lightning II requirement was initially put as high as 150, but even the eventual 138 figure has been reduced, with the country cancelling its F-35B variant order in favour of F-35C aircraft. The final UK requirement is not publicly known, but a halving has been mooted, with even a figure as low as 50 having more recently been suggested. The UK had ordered three F-35B test aircraft, and, in its preliminary 2010 annual report, BAE Systems says that production of two of these form part of Lot 3, which is on schedule, while the third was part of Lot 4 (also ongoing). Development aircraft deliveries plus Lots 1 and 2 have been completed, says the company.
In the UK, apart from BAE Systems' major involvement in the JSF programme, Rolls-Royce is heavily involved with the STOVL variant of JSF, the F-35B, with the company manufacturing its Rolls-Royce LiftSystem to support vertical thrust. But in January 2011, the F-35B variant was placed on "probation" in the US for two years, because of development issues.
Rolls-Royce, in partnership with America's GE, is also involved with the development of the alternate engine for all JSF variants, the F136, but the future of the F136 programme, now 80% complete, is in the balance, due to defence funding cut discussions in the US. And even the two companies' offer to self-fund the remaining development may also be vetoed.
Apart from these high profile UK companies, there are estimated to be around 100 other UK firms involved in F-35 Lightning II work. According to an Aviation Week report dating to 2004, even at that stage, JSF work to the value of over $3.3 billion had been awarded to UK firms.
But contribution and work gained were never in strict workshare relationship, unlike many other defence programs. Indeed, in its 2010 preliminary statement, BAE Systems said that the UK's decision on reduced F-35 Lightning II requirements would not impact it. "BAE Systems' workshare arrangements are not matched against the UK's decision on aircraft type or quantities."
The investment and momentum behind the F-35 Lightning II programme are unstoppable, even though volumes will be lower, and the UK seems set to play its part in the project for many years to come. The BAE Systems titanium machining facility is one demonstration of that.
Box item 2
Building 610 facts
• The building is structured to have a clean and dirty side. All materials are received at the rear of the building and brought into the facility from there, with part-finished materials exiting the same way. The swarf vacuum and centrifuge systems are also within the 'dirty' area of the plant, while the machining area is a forklift-free area, these only operating in the dirty area.
• The facility is not temperature-controlled (outside the inspection room), but the rate of change of temperature is, with a maximum ½ °C/hour movement. FMS machine tool coolant is controlled to between 22-23 °C. Currently, two machines are fitted with 100 bar coolant, with this then rolled across the others.
• There are no gutters on the building, avoiding any maintenance, and a sacrificial wall has been built into the right-hand side of the building, allowing for easy extension to the facility.
• Flexible approach to the building - 10,000 square metre building with large span bays, designed to enable flexibility of machine choice and phased machine installation plan with minimal impact to production. Achieved 2nd place in National Builders awards for CDMC
• Manufacturing Industry Award Winner – March 2011 - The award recognised the partnered approach taken by the team, which included StarragHeckert, Fastems, TDM Systems and Nederman, in delivering a flexible manufacturing system (FMS) to produce complex titanium parts for the F-35 Lightning II aircraft.
The team received the award for Best Supplier Partnership at the first ever Manufacturing Industry Awards held in Birmingham. The awards, hosted by the Manufacturing Technologies Association, recognise the success and significance of engineering based manufacturing in the UK.
• Energy efficient - The building buy design is energy efficient and environmentally friendly, utilising the latest technologies in advanced materials which therefore benefits in the maintenance and service of the facility over the life of the project. This level of innovation and use of best practice has enabled the building to be accredited with a BREAM rating of 'very good' for energy efficiency.
• Investment into Samlesbury site - The aerospace industry is vital to the North West. At Samlesbury, the investment and development currently being undertaken offers big benefits to the aerospace sector and to the region as a whole.
First published in Machinery, June 2011