Lockheed Martin is redefining what it costs to develop and produce a new combat aircraft
Graham Warwick/Fort Worth
Two imperatives drive almost every operation at Lockheed Martin Tactical Aircraft Systems: keeping the F-16 in production, and winning the Joint Strike Fighter (JSF) competition. Both goals share one prerequisite - affordability. Of all the "ilities" to gain currency within the military aviation community, affordability is perhaps the most crucial. Without it, fewer and fewer new combat aircraft will be purchased.
It was former Lockheed Martin chairman Norman Augustine who calculated that, if cost trends continued unbroken, eventually it would require the entire US defence budget to buy just one fighter. Now the company he helped create is mounting a concerted effort to buck that trend.
Lockheed Martin, which dubs its combat aircraft operations "The Fighter Enterprise", has more than most to lose if it cannot break Augustine's curve. The US manufacturer builds the F-16, is prime contractor on the F-22, produces major parts for Japan's F-2, will help South Korea develop the KTX-II, and is one of two contenders for the JSF programme.
There are promising signs of progress at the company's Tactical Aircraft Systems division in Fort Worth, Texas, where, over the past four years, the cost of the F-16 has been cut despite falling production rates. But what has been achieved so far is not enough, the company says.
THE AFFORDABLE F-16
More progress is needed, company officials say, to make the F-16 affordable for countries that want the fighter, and to ensure that the JSF programme survives and that Lockheed Martin wins the contest against Boeing. To achieve that progress, Lockheed Martin is introducing The Fighter Enterprise Production System and has launched the Virtual Product Development Initiative. Together, they are intended to reduce substantially the cost and time required to develop and produce combat aircraft while improving the quality of the end product.
The production system now being introduced at the Fort Worth plant has two major pillars: lean manufacturing principles and advanced manufacturing methods. Larry Pike, director of lean deployment, says that targets for 2002 include reducing the time from order to delivery for an F-16 to under 18 months, from today's 22 months - down from 36-42 months in 1989-92. At the same time, schedule performance and delivery quality are to be improved, and the cost of the F-16, excluding Government-furnished equipment, is to be almost halved from where it was a decade ago.
"How good do you have to be?" asks Pike. "There are customers who would like more F-16s, but don't have the money. We have to decide what the affordability threshold is." A similar equation applies to the JSF - unlikely to materialise if it cannot be made affordable enough for the Us forces. This will require reducing development, support and production costs substantially from today's levels.
By the start of JSF engineering and manufacturing development in 2001, the company's five-year Virtual Product Development Initiative (VPDI) aims to deploy software tools to reduce cycle time and cost by 50% for development and manufacture and by 30% for maintenance.
The initiative is creating a virtual development environment (VDE) which can model and simulate almost every aspect of a programme, from design, through fabrication and assembly, to in-service support. The VDE will comprise a suite of software tools that will allow the developer to create virtual prototypes of everything from the business process to the factory floor, using correlated databases tied to the electronic product definition of the aircraft under development.
Linda Poole, VPDI programme manager, says that the initiative will enable the aircraft to be designed for affordability. "It will enable us to eliminate unplanned changes, physical mockups and most testing." The environment will allow engineers to look at more alternatives, to optimise the design, while also reducing the development span, she says. Use of tools such as assembly simulations will allow planning for production to proceed in parallel with design - and, crucially for the JSF, the system will allow development to be performed collaboratively by several sites - and companies.
To create the virtual development environment, Lockheed Martin is integrating a suite of "best in class" software tools, Poole says. Central to this effort is the product data management system, for which Structural Dynamics Research's Metaphase has been selected. This stores the design as a database of solid models, with their geometric and parametric associations, with other parts and processes.
This results in a "ripple effect" as design changes are reflected automatically, through the product data management system, in all aspects of the development environment affected. Poole says the time required to modify the design of a bulkhead, for example, can be cut "from three weeks to 3min" using the system.
The product data management system has time-saving features, including the ability to store a library of generic parts, such as clips and brackets, which can be used by the designer. Or, if an additional fuselage bulkhead is required, for example, an existing design can be replicated and automatically adapted to its location in the aircraft. "Build-to" packages can be released based on solid models, rather than drawings.
Lockheed Martin is expanding the system's capability by integrating other tools that will be viewable to the developer on the same workstation. These include "design-with-cost" analysis tools which will let the designer "...know the cost implications of a change in a part while it is still on the screen", Poole says. Integration of manufacturing, tooling, assembly and support simulations will enable designers to validate that the aircraft can be fabricated and operated before any metal is cut.
DIGITAL MOCKUPS
"All the simulations are physics-based," Poole says, meaning that the visualisations use actual product data drawn from the design database, and are therefore not mere "cartoons". One reason for assembling a suite of software tools is that the IBM/Dassault Syst‚mes CATIA three-dimensional design environment used to create the aircraft is too unwieldy for use in most virtual prototypes. All simulations use the same basic product data, but the fidelity of the model is matched to the purpose of the prototype.
Engineering Animation's (EAI) VisProducts software is used for product visualisation and to create digital mockups, for example, because it is more suited to the tasks than is CATIA. "There is a lot of overhead in a CAD [computer-aided design] model," says one engineer. With VisProducts, the entire 37,000-part JSF mid-fuselage can be visualised on screen.
EAI's VisFly visualisation software will be used to conduct design reviews over networks linking several sites, enabling all participants to view the same digital representation of the design element under review. Lockheed Martin will use EAI's VisMockUp software to confirm that parts fit together, and then check the assembly sequence. "We use the software to look for interference. Repair is done in the CAD system," the engineer explains. If parts interfere, a visualisation of the conflict can be marked up and e-mailed to the designers involved.
The software also allows the designer to take the "bill of materials" for a component - the list of parts and their assembly sequence - and watch it assemble on screen to check for collisions. If something looks wrong, the designer can "drag and drop" those parts to re-order the assembly sequence. Similar visualisations will be provided to assembly workers - "they'll be able to touch a part and see its number", the engineer says - and embedded in the technical manuals delivered with the aircraft.
Manufacturing simulations being integrated into the virtual development environment include a Deneb Robotics system for analysing assembly-line ergonomics. This warns if a part is too heavy to load into a tool or if a rivet is too high for a worker to reach. The simulation has resulted already in a change to the assembly concept for the JSF inlet ducts.
The same simulation software can be used to generate or validate the programming of a drilling and riveting robot, and to measure assembly times. Lockheed Martin has used the tool to simulate the operation of a paint robot, measure the resulting paint thickness and then modify the program to achieve the required coating application tolerances.
Another manufacturing simulation is a factory fly-through created using "virtual reality" (VR) visualisation software from UK company Division. Using a head-mounted VR display, the designer is able at will to move through a simulation of the proposed JSF assembly line which is based on actual design data.
MODELLING TOOLS
The virtual development environment also includes a suite of weapon system modelling tools. These include Paradigm's Vega visual simulation software, which is being used, for example, for pilot-in-the-loop evaluations of the carrier suitability of Lockheed Martin's JSF design. Additional modules allow the simulation of infrared sensor performance in various accurately modelled atmospheric conditions. Aircraft infrared and radar signatures can also be modelled. Again all these simulations are "physics based", engineers emphasise.
Keeping all these interlinked models and simulations in step as a design evolves would appear to be a nightmare task, with changes in one area affecting all others, but Poole says that the product data management system ensures configuration control. The system alerts all those affected by a proposed design change before it becomes effective, she says.
To keep implementation of the virtual development environment within manageable proportions, given the 2001 deadline, rather than simulating the entire process of developing a combat aircraft "Éwe are going for the things which have specific cycle time and cost implications," Poole says.
Source: Flight International
