Forgings Will Help to Power Super-Sized Airliner

June 5, 2004
Airbus recently started manufacturing its A380 Superjumbo. Kobe Steel is supplying titanium forgings for one of two engine designs on what will be the largest commercial airliner ever built.

European aircraft maker Airbus SAS launched production of its super-sized A380, the biggest-ever commercial airliner, by unveiling the first fuselage in a ceremony on May 7 at an assembly plant near Toulouse in southern France.

A few days earlier, Rolls-Royce announced that its engine for the A380, dubbed the Trent 900, successfully completed its latest round of performance testing at the Arnold Engineering Development Center (AEDC), in Tullahoma, TN. It is scheduled to be the first engine to enter airline service when the first A380 is released to Singapore Airlines in 2006.

Boeing, America’s leading aircraft manufacturer, also recently announced a new project, the 7E7 Dreamliner, a new mid-size airliner that promises highly efficient operation.

The aerospace market is an important one for the forging industry, so these announcements are significant for the domestic and world forging industries.

Forgings from Kobe Steel
One company that capitalized on the publicity rollout accompanying the A380 production launch was Japan’s Kobe Steel, Ltd. It recently issued a press release that it has begun supplying titanium forgings for use in the Rolls-Royce Trent 900.

Kobe Steel shipped its first ring forging in January. Kobe Steel furnishes the double-melt Ti-6Al-4V titanium alloy rings to Kawasaki Heavy Industries, which processes the metal into intermediate pressure compressor casings. The completed casings are then shipped to Rolls-Royce for fabrication in the Trent 900 engine.

Over an initial five-year period, Kobe Steel will be the sole supplier of titanium rings to Kawasaki for the Trent 900 casings, while Kawasaki is the sole supplier of the casings to Rolls-Royce. Kobe Steel credited its many years of collaboration with Kawasaki with gaining the Rolls-Royce order.

It’s not surprising that Kobe Steel would be the first to tout its involvement in supplying forgings to the Airbus project. Not only does Kobe produce the forgings; as Japan’s only integrated titanium producer, it also produces the titanium alloy. Details of Kobe Steel’s titanium production and forging operations are provided in a sidebar on page 16.

Other forged products being produced for the A380 no doubt will be unveiled as time goes on.

World’s largest airliner
The Trent 900 engine is the launch engine for the A380 and will be used on 48 per cent of the aircraft on order to date, according to Rolls-Royce. The A380 will also be powered by the GP7000 family of engines from the Engine Alliance between Boeing and Pratt-Whitney.

The story of the A380 begins in the early 1990s, when Airbus first began studies on the feasibility and interest in a 500-seat airliner. The European consortium saw developing such an airliner as a strategic move to end Boeing’s dominance of the very large airliner market. It also would round out Airbus’ product lineup.

Airbus began engineering the A3XX, in June 1994. After considering numerous design configurations, Airbus settled upon a twin-deck configuration, with seating for 555 passengers, which easily eclipses the Boeing 747.

Key design aims include the ability to use existing airport infrastructure with few modifications to airports, and direct operating costs per seat 15-20% less than those for the 747-400. With 49% more floor space and only 35% more seating than the previous largest aircraft, Airbus will offer more passenger comfort with wider seats and aisles.

The A380 will feature an advanced version of the Airbus common two-crew cockpit. It also will use four 72,000- to 78,000-lb-thrust Rolls-Royce Trent 900 or Engine Alliance GP-7200 turbofan engines. These engines promise to produce 10-15% more range, lower fuel burn and emissions, and less noise.

Several A380 models are planned: the basic aircraft is the 555-seat A380-800 and high-gross-weight A380-800, with the longer-range A380-800R planned. The A380-800F freighter will be able to carry a 150-metric ton payload and is due to enter service in 2008. Future models will include the shortened, 480-seat A380-700, and the stretched, 656-seat, A380-900. The -700, -800, and -900 designations were chosen to reflect that the A380 will enter service as a “fully developed aircraft” and that the basic models will not be soon replaced by more improved variants.

The A380 carries a price tag of $280 million. Apart from the first fuselage - to be used exclusively for ground-based testing - the first complete Superjumbo is set to trundle off the assembly line in July.

Boeing, meanwhile, has settled on offering the 7E7 Dreamliner, a fuel-efficient mid-sized jet carrying up to 300 passengers. It is expected to enter service in 2008.

While Airbus is betting on the hub-and-spoke network model of air travel, Boeing has come to believe the future lies in direct point-to-point services, as traffic volumes grow and customers increasingly spurn the time-consuming detours and changeovers caused by airlines channeling passengers through hub airports on their way to their ultimate destinations.

So far, Airbus has 129 firm orders for the 555-seat A380. The new A380 plant should be turning out four planes a month by 2006, according to Airbus officials. Boeing received an order for 50 of its Dreamliners in April.

Trent 900 engine
Rolls-Royce is the second largest jet engine manufacturer, after GE Aircraft Engines.

Its Trent 900 Series is a family of high-bypass turbofan jet engines, producing 80,000 lb of thrust. The Trent features a wide-chord fan, with single-crystal high-pressure turbine blades. Fan diameter is 116 in. The engine’s core turbo machinery is brand-new, giving better performance, with lower noise and pollution levels. (Editor’s Note: “Trent” is a label chosen according to the Rolls-Royce practice of naming engine families after English rivers. The Trent is England’s only north-flowing river.)

Engine Alliance captures A380 business
The Engine Alliance, a 50/50 joint venture between GE Aircraft Engines and Pratt & Whitney, was formed in August 1996 to develop, manufacture, sell, and support a family of modern technology engines for new high-capacity, long-range aircraft.

In mid-1996, Boeing announced it was beginning development of new growth derivatives of the venerable 747, the 747-500/600. Neither GE Aircraft Engines nor Pratt & Whitney had engines in their own product lines in the necessary 70,000-85,000-lb thrust range. Each company had independently forecasted worldwide demand for aircraft in this market segment and determined that it might not be large enough to justify the approximate $1-billion cost to develop a new engine. Still, the market segment and potential customer base were too large to ignore. A joint venture between these otherwise aggressive competitors seemed the logical solution. Therefore, on August 28, 1996, GE and Pratt & Whitney established a joint venture company named GE-P&W Engine Alliance, LLC to develop the GP7000 engine.

The idea was to use the core competencies of each parent company to design, develop, certify, and manufacture a state-of-the-art high-bypass turbofan engine for 450-seat and larger four-engine aircraft.

Eventually, Boeing shelved plans for a growth 747 version. In the meantime, Airbus began to study development of an aircraft called the A3XX, to be the largest-ever commercial transport. Airbus approached the Engine Alliance about supplying engines for the new airplane. The EA supported Airbus preliminary development with various GP7000 engine designs for the A3XX between 1998 and 2000. Airbus made it official on December 19, 2000 by launching the A380 program.

On May 19, 2001, the Engine Alliance launched the GP7000 program when Air France selected the GP7270 to power their 10 A380-800 passenger aircraft on order.

The GP7000 family is derived from two of the most successful wide-body engine programs in aviation history - the GE90 and PW4000 families. Those engines have demonstrated industry-leading reliability from service entry.

By mid-May, the Engine Alliance had captured 52% of the orders for its GP7000.

Boeing goes mid-size
Boeing, whose plans to build an enlarged jumbo led to the Engine Alliance joint venture, eventually settled for the 7E7 Dreamliner, a fuel-efficient mid-sized jet that will accommodate 200 to 300 passengers. It is expected to enter service in 2008.

Boeing chose GE Aircraft Engines and Rolls-Royce to supply two engine types for the Dreamliner. Boeing calls the 7E7 “an airplane that will provide the world’s airlines with exceptional efficiency and environmental performance.” It said the choice of the two engines is based on the results of several months’ collaboration with the top commercial airplane engine designers.

The 7E7 program is due to get underway this year. Boeing has already booked an order for 50 of the jets from All Nippon Airways, and has submitted firm contract proposals to other airlines.

The Dreamliner will be a family of three plane designs: the base model will carry 217 passengers in three seating classes and a flying range of 8,500 nautical miles. A shorter-range 7E7 will carry 289 passengers in two seating classes and travel up to 3,500 nautical miles, and a stretch-version 7E7 will carry 257 passengers in three classes up to 8,300 nautical miles.

“The General Electric and Rolls-Royce engines will enable the 7E7 to fly higher, faster, farther, cleaner, quieter and more efficiently than comparable airplanes,” said 7E7 senior vice president Mike Bair. “Having an engine choice is a key consideration for our customers. We’re now offering two excellent options for the 7E7.”

The 7E7 is seen decreasing fuel consumption, and the accompanying exhausts, by 20% versus comparably sized current designs. The engines themselves will help reduce airplane noise significantly, and meet new noise-control requirements on the airlines.

The two engines are the General Electric GENX and Rolls-Royce Trent 1000. Both engines will be able to provide 55,000-70,000 lb of thrust, and either design will be applicable to each of the three 7E7 models that Boeing plans.

The GE Next Generation (GENX) engine is derived from the ultra-high-thrust GE90 model, already proven in twin-engine aircrafts. The GENX will have composite fan blades, the highest pressure-ratio compressor in aviation, and a single-annular combustor where compressed air and fuel are mixed, to lower emissions. It will have its first full-engine test in 2006. Design and testing will be done at GE Transportation’s headquarters in Evendale, OH, and assembly will be done in Durham, NC.

Rolls-Royce’s contribution to the 7E7, the Trent 1000, will be a new, fifth variant of its high-thrust Trent engine series. It will have the Trent three-shaft design layout, and Rolls predicts “it will be the most efficient and environmentally advanced Trent ever built.”

Both engines will use the same standard interface with the airplane so they are entirely interchangeable, a first in commercial aircraft design. Boeing says the interchangeability will make the 7E7 a flexible asset that can easily be exchanged among carriers — a selling point for financiers, leasing companies, and airlines.

In April, Japan’s Kobe Steel, Ltd. announced that it had begun supplying titanium forgings for use in Rolls-Royce’s aircraft engine, the Trent 900, developed for the Airbus A380, and in the IAE V2500 engine for the A320.

For the A380 engine, Kobe Steel furnishes its double-melt Ti-6Al-4V titanium alloy rings to Kawasaki Heavy Industries, which processes the metal into intermediate pressure compressor casings. The completed casings are then shipped to Rolls-Royce for fabrication in the Trent 900 engine.

Kobe Steel has targeted the aircraft industry as a strategic market. In their market forecasts, both Boeing and Airbus predict that overall demand for passenger aircraft will double over the next 20 years. This trend is anticipated to increase demand for titanium products from engine and aircraft manufacturers.

Kobe Steel, with offices in Tokyo and Kobe, is one of Japan’s leading steelmakers and producers of aluminum and copper products. It also is Japan’s only integrated producer of titanium mill products, with production capabilities ranging from ingot-making to product manufacturing. Other main businesses include welding consumables, engineering, and machinery.

Kobe Steel also is proud of the fact that it is supplying Rolls-Royce with titanium forgings used in high-pressure compressor disks for the IAE V2500 engine for Airbus A320 aircraft. Kobe Steel makes the triple-melt Ti-6Al-4V forgings at its Takasago Works in Takasago, Japan and delivers them directly to Rolls-Royce’s plant in Oberursel, Germany. The supply contract for the disk forgings covers a period of three years, from 2003 to 2005. The first shipment went out in January this year.

Kobe Steel regards it as a significant milestone, the first time that a Japanese titanium manufacturer has been qualified to directly supply titanium products to Rolls-Royce. Forgings for high-pressure compressor disks are some of the most critical titanium products to manufacture, from the standpoint of toughness and metal cleanliness. Of the numerous components that go into jet engines, rotating parts require extremely high toughness, and impurities in the metal can affect the strength of the material.

Engine consortium. IAE International Aero Engines is a multinational aircraft engine consortium with shareholders from four countries and three continents. As a leading partner, Rolls-Royce is responsible for the design and the manufacture of the high pressure compressor and the final assembly of the IAE V2500 engine. Other IAE shareholders comprise Pratt & Whitney, the Japanese Aero Engines Corp., and MTU Aero Engines.

IAE claims its V2500-A5 engine is the quietest engine available for the Airbus A320 family. It is the only engine that meets the latest Chapter 4 ICAO noise requirement for all A320 family aircraft. With an average market share of 57% over the past six years IAE’s V2500 has become the engine of choice for Airbus single-aisle aircraft. More than 950 V2500-powered aircraft have been delivered and the worldwide fleet has accumulated over 27 million flying hours.

Titanium production. Titanium production at Kobe Steel is centered at the Takasago Works is in Takasago, Hyogo Prefecture, in western Japan. It has two segments, the Iron and Steel segment, which includes titanium production, steel casting and forging, and a steel powder production facility; and the Machinery segment.

Kobe Steel is the only Japanese manufacturer engaged in integrated production of titanium products, from refining of titanium alloys from ore through ingot making and rolling and forging into final products. Production of titanium products, including forging, is performed on equipment also used for steel processing. Dedicated facilities and equipment for the production of titanium mill products consist of only the VAR furnaces and ring mill at Takasago Works. Certain processes for titanium flat products are performed at Kobe Steel’s Kakogawa Works.

Production of titanium at Takasago Works begins when titanium sponge undergoes compaction and is turned into electrodes, which are remelted in the VAR furnaces to form ingots.

Kobe Steel uses modified VAR (vacuum arc remelting) furnaces for ingot-making. A patented side-feed system (Kobe Method) attached to the furnace shaft enables the furnace to recycle titanium scrap arising from mill operations.

The ingots then go to the 8,000 metric ton press for breakdown forging into blooms. From there, the blooms are sent to the 3,000 metric ton press, where billets are formed. Using a large ring rolling mill Kobe Steel then processes the billets into titanium rings.

For the A380 engine ring forgings, Kobe handles heat treatment and machining, and then ships them to Kawasaki Heavy Industries, where they are further processed into compressor casings.

In addition to forgings, Kobe Steel’s Titanium Division makes sheet and plate, bar and welded tube. In general, the titanium mill products are manufactured at the same rolling mills used in steel rolling operations. Titanium sheet and plate products are made at Kakogawa Works, Kobe Steel’s flagship steel mill for flat products. Titanium bar is produced at Kobe Works, which specializes in long steel products. (Kakogawa Works and Kobe Works are Kobe Steel’s only two integrated steel works.) Titanium tube is made at Kobe Special Tube Co., Ltd., a 100% subsidiary, in Yamaguchi Prefecture.

With its world-class melting technology, Kobe Steel began early on to develop titanium alloys and currently has a 50% domestic share of this market. Kobe Steel’s titanium is used in a wide range of applications, covering the industrial and aircraft as well as consumer markets. The company is actively pursuing development of new titanium alloys.