F-35 Joint Strike Fighter (JSF) Lightning II
Manufacturing
The F-35 team has developed and prototyped state of the art manufacturing concepts, tooling, and techniques as part of the JSF Concept Development Program. Lockheed Martin completed a comprehensive Airframe Affordability Demonstration (AAD), which demonstrated innovative fabrication, assembly, and tooling techniques for use on JSF. In addition, Northrop-Grumman and BAE SYSTEMS demonstrated advances in composite technologies and flexible tooling which will greatly reduce the cost and time for manufacturing.
The JSF team is employing advanced assembly methods and highly accurate manufacturing machines to help the F-35 achieve its goals of affordability, quality and assembly speed. New milling machines accurate to less than the width of a human hair, ensure that the F-35’s outer shape is exact and meets its low-observability (stealth) requirements. Assembly time for an F-35 is planned to be less than half that of current-generation fighters. The F-35 JSF production line will be the state-of-the-art model for high-quality, affordable combat aircraft in the 21st century.
In 2003, Lockheed Martin and the JSF Program Office reached an agreement with the Deputy Secretary of the Air Force for Acquisition to allow Lockheed Martin and Northrop Grumman F-35 assembly plants in Fort Worth, Texas, and Palmdale, Calif., to operate as unclassified facilities. The team reached additional agreements to downgrade the classification of some F-35 parts and materials, which will result in a significant reduction in factory operation and supplier costs.
The F-35 JSF assembly line will build on the capability demonstrated with the F-16 and other "'lean-manufacturing" aircraft. Advanced production processes, including integration of the digital, paperless factory, are being implemented into F-35 production plans. Lean manufacturing principles, incorporation of shortened flow spans, use of a single, flexible production line for all three variants, use of best-value sourcing within a commercial framework — all these steps will yield measurable results in the production phase.
The F-35 assembly line will be notable for its automation, reduced tooling, and virtual elimination of hammered rivets. The subassemblies will be loaded into simplified tooling capable of building any of the F-35 variants. The machine will do its work, and the entire assembly- tool and all- will move to the next position. Previous manufacturing technologies would require different tooling for each variant as well as require the subassembly to be unbolted from one tool and reinstalled in another before the next process could proceed- a time-consuming exercise. Because the three variants have more than 80 percent of their parts in common, all of which are located in the assembly tooling in a common manner, major components such as bulkheads can be manufactured from the same blanks, milled and drilled on the same fixture, and assembled using common tools. Again, using the bulkheads as an example, the only difference among the variants is their thickness.
In Fort Worth, an array of advanced and extraordinarily precise manufacturing machines was finished for the production of the F-35 forward fuselage and wing. Some of the equipment is the largest that has ever been built. The huge Flexible Overhead Gantry, for example, will mill the inside surface of the F-35’s composite skin to ensure that the aircraft’s outer form is exact – a critical step in assuring stealth performance. Accurate to 50 microns (one micron equals one-millionth of a meter) and working in both horizontal and vertical motions, the machine is unprecedented in its size and purpose.
The main task is to build the aircraft affordably. the F-35 JSF Airframe System Engineering Integration Team wante to eliminate as much tooling as possible, improve production flow, and reduce disruption and delays. By using precise fabrication and robust assembly methods, it is possbile to eliminate hand fitting and rework as the assemblies come together. The contractors are not using technology for technology’s sake; but rather are using technology to reduce cost.
Although the automotive industry was not a direct source of expertise for the F-35, it was a source of inspiration to the people who will build the aircraft. Automotive plants don’t keep inventory on an auto assembly line. They only have about two hours worth of inventory on the floor at any given time. Even the seats come off the delivery truck in sequence of installation. Our assembly line will resemble that line. It is called mixed-model production. Lockheed won’t have three assembly lines, it will have one line, which might build a CTOL version today, a STOVL version tomorrow.
Comparing the F-35 to current-generation fighters, engineers project that Lockheed Martin F-35 assembly will reduce tooling by 90 percent, reduce manufacturing time by 66 percent, reduce manufacturing costs by more than 50 percent, require up to 50 percent fewer parts, and require up to 50 percent fewer fasteners.
Leveraging decades of experience in advanced tactical fighters, long-range strike aircraft and systems integration, Northrop Grumman’s work on the F-35 program reflects the engineering excellence and systems know-how that built the company. Northrop Grumman is responsible for more than 25 percent of the F-35 aircraft. Its contributions range from integrating the center fuselage to producing key subsystems such as communications and avionics, and developing software for mission planning.
The company’s approach to improving manufacturing efficiency reflects five elements: people, process, tools, technology and infrastructure. Each has an important role to play. The skills required of Northrop Grumman’s manufacturing workers are changing to meet the new requirements. More broadly, adoption of lean principles throughout the enterprise requires employees to develop what are called “soft tools”—the skills to understand their process and question the value of each step. Because of these changes, manufacturing workers today are more highly trained than ever before and more familiar with automation and computer technology.
Northrop Grumman has instituted lean processes, advanced producibility analysis and ergonomic simulations to support the F-35’s rigorous production schedule. The results of using lean tools direct the engineering team towards the most desirable solution and factory layout. lean techniques will also be applied to procurement processes to ensure just-in-time flow of parts and raw materials.
Military aircraft specifications require tight tolerances in the manufacturing process, and automation/robotics help in repetitive tasks that require precision such as drilling holes or applying paints and coatings. Automation is especially important in F-35 assembly, where the production rate is expected to reach one per day.
Northrop Grumman is using several state-of-the-art tools to insure the program stays on course. Precision milling machines trim moldlines, side surfaces and radii; counter bores; and drills holes in composite parts, all at feed rates of up to 600 inches per minute. The 24,000-RPM precision cutter is more than capable of holding all engineering tolerances required for F-35 program parts. A fiber placement machine utilizes new programming technology to wrap tooling mandrels with layer upon layer of carefully directed fiber tape plies. The paint cell employs state-of-the-art robotic technology to apply coating to the insides of the contoured engine air inlet ducts.
In laying out the factory, Northrop Grumman adapted vehicle movement techniques from the automotive industry. Lean principles and a high degree of automation have been incorporated to support the rigorous processes required for the F-35 to remain on schedule. Automated drilling stations produce high quality precision holes. New techniques available through today’s computer systems allow the company to analyze and predict the possible outcomes for countless scenarios. Software tools such as advanced computer aided design packages, product data management, production and process simulations, and virtual enterprise environments all contribute to realizing these objectives.
Working as an integrated team with customers, teammates, and suppliers, Northrop Grumman will deliver products that perform as it supports Lockheed Martin’s continuous moving line concept and the ultimate one-a-day delivery to the military customer. Product designers, system engineers, manufacturing engineers and quality engineers work in closely coordinated integrated products teams (IPT) to define the requirements needed to quickly match the F-35’s cutting-edge design with production process capabilities and supplier capabilities. Real-time interaction with suppliers, as well as open communication channels among partners, maximize the use of best processes across the team.
But as of early 2005 it appeared that the JSF program will lack critical production knowledge when it plans to enter low-rate initial production in 2007. Between 2007 and 2013, when the program is scheduled to move to full-rate production, it expects to buy nearly 500 JSF aircraft—20 percent of its planned total buys—at a cost of roughly $50 billion. Under the program’s preliminary plan, it expects to increase low-rate production from 5 aircraft a year to 143 aircraft a year, significantly increasing the financial investment after production begins.
Between 2007 and 2009, the program plans to increase low-rate production spending from about $100 million a month to over $500 million a month, and before development has ended and an integrated aircraft has undergone operational evaluations, DOD expects to spend nearly $1 billion a month. To achieve its production rate, the program will invest significantly in tooling, facilities, and personnel. According to contractor officials, an additional $1.2 billion in tooling alone would be needed to ramp up the production rate to 143 aircraft a year. Over half of this increase would be needed by 2009—more than 2 years before operational flight testing begins.
In its fiscal year 2006 budget submission, DOD reduced the planned procurement quantities for the U.S. by 38 aircraft through fiscal year 2011. The preliminary figures also includes planned quantities for the United Kingdom of 2 aircraft in fiscal year 2009, 4 aircraft in fiscal year 2010, 9 aircraft in fiscal year 2011, 9 aircraft in fiscal year 2012, and 10 aircraft in fiscal year 2013.
