By the end of this month, Airbus France will deliver the first forward fuselage section for the A400M military transport. Almost simultaneously, Airbus Military (Hall 4 Stand A13) is set to complete construction of its final assembly line in Seville, Spain. Final assembly of the first A400M should start during the first quarter of next year.
The program is progressing almost on schedule toward first delivery in October 2009 to the French air force. However, Airbus is continuing to attempt to shed further weight from the airframe to allow for as much as six more metric tons of fuel and higher payload requirements. The manufacturer plans the A400M’s maiden flight before the end of the first quarter of 2008.
Six aircraft will carry out 2,500 hours of flight tests at Toulouse and Seville. European countries have no common rules for certifying military aircraft, so the A400M partner governments opted to save time by agreeing to a civil approval process to cover initial operations capability. Further certification work will deal with military requirements, common or national. In fact, the A400M will not be certified as a civil transport aircraft, but 80 percent of its systems and equipment–including its TP400 engine–will be.
A second developmental flight deck will be operational this September. The cockpit features fly-by-wire controls and will look like the A380 cockpit, with its displays in a similar configuration. “Both programs have the same suppliers, which enables economies of scale,” an Airbus Military spokesman told Aviation International News. The A400M flight deck is designed for a crew of two. However, a third seat is available for a load master or a mission manager, who operates defense systems.
In April, GKN Aerospace delivered a major part for the aircraft–the first composite wing spar. The A400M’s 66-foot spars represent the first-ever application of carbon composites for a primary structure on a large transport aircraft wing. The wing on the A400M incorporates two front and two rear spars, each in two sections. Each has fully integrated carbon pads to allow attachment of associated structures, such as engine nacelles and flap track beams.
Mtow for the A400M is now 136.5 metric tons, up from 130. However, Airbus insists that while there is no guarantee on the aircraft’s final weight, there is for its mission capability–such as the requirement to carry a 20-metric-ton payload as far as 3,450 nm.
One of the program’s innovations is the single-phase development model that it has taken from the civil aircraft sector. Governments usually chop up military programs into several phases– preliminary design, development, production and so forth–releasing money at these various stages and, often, changing some specifications in the course of the program, slowing down the development.
With the A400M, customers buy a defined aircraft specification. They sign up for a firm configuration and pay part of the final price when placing the order. This locks them into guarantees in performance, delivery schedule and price. The manufacturer gets a guaranteed payment and number of orders. However, according to Airbus Military’s spokesman, such a program has not proved easy to introduce to military customers, simply because it is a new concept.
Another benefit to the civil approach should be the aircraft’s eventual dispatch reliability. The target for the A400M is equivalent to that of the A320, that is, greater than 98 percent. “The main feature leading to such reliability is the fact that, based upon Airbus’ experience in the civil field, maintainability has been designed into the aircraft at the conceptual stage,” the spokesman commented.
The A400M has so far won 192 firm orders, the most recent coming last year from South Africa (eight) and Malaysia (four). The program was launched in May 2003 with 180 orders from seven nations.
Airbus Military will deliver three aircraft in 2009. Then it will deliver 17 in 2010, 27 in 2011 and 26 in 2012. The production rate will eventually hit 30 per year. Airbus Military Sociedad Ltda. is a Spanish legal entity, jointly owned by Airbus (64.8 percent), EADS Casa (25.8 percent), Turkish-based Tusas Aerospace Industries (5.2 percent) and Belgium’s Flabel (4.2 percent).
Engine on Track
Development of the A400M’s TP400-D6 turboprop engine also is on schedule. This is an achievement for an engine that is simultaneously complex (with three shafts), the most powerful turboprop in the Western world (11,000 shp), and as a multinational program, tricky to manage (Spain’s ITP, Germany’s MTU, the UK’s Rolls-Royce and France’s Snecma are partners in the Europrop International joint venture).
The first engine was tested in October 2005 in Ludwigsfelde, near Berlin. After 35 ground test hours, which included reaching maximum power, it was fitted with its propeller. The latter, manufactured by Ratier-Figeac, has eight blades and its diameter is an impressive 17 feet. The company ran the combination in February at its facility at Istres in the south of France, and it has since logged more than 30 hours.
Engine number three started running in Berlin, too. Engine number two, heavily instrumented, joined number three in mid-June. By the end of this week, total test time should have exceeded 150 hours.
Some 10 new engines eventually will be involved in the test program–including one in flight. “We’ll actually make a total of twenty engines out of these ten after having rebuilt most of them with several different modules,” Jacques Desclaux, the Europrop International (EPI) consortium’s program and operations director, explained to AIN.
The program will employ six ground testbeds. Three are sea-level indoor facilities hosted by MTU in Ludwigsfelde, Techspace Aero near Brussels and ITP near Madrid. The fourth facility, for altitude simulation, is operated by the Centre d’essais des propulseurs in Paris’ outskirts. The remaining two are outside-air facilities at Istres and Seville.
The flying testbed, managed by Airbus, will be a special C-130 modified by the UK’s Marshall Aerospace. Use of multiple testbeds allows squeezing development into 55 months rather than the 10 years that would be required with more conventional methods, thanks, in part, to conducting tests in parallel instead of sequentially.
The certification program–estimated to take a total of 2,000 hours–is to be completed in the third quarter of 2007. Still to be performed are more vibration and icing tests, as well as bird and hail ingestion, and endurance tests. The next contractual milestone is flight-test engine delivery to Airbus this December.
Between June 2007 and April 2008, EPI will build 28 engines, including four spares, for Airbus’ six flight-test A400Ms. The consortium will then have to face a hiatus until production starts late in 2009.
According to Desclaux, the TP400 is ahead of its weight target. “We still need some testing to validate our latest weight-saving modifications,” he said. The average engine weighs 4,103 pounds but this is only a virtual engine. Two engines will be heavier because of the addition of a gear, and the other two lighter. This difference is needed to create the “down-between-engines” configuration.
On each wing, opposite rotation of the propellers creates a downward airflow between the engines. This aerodynamic configuration is symmetric and therefore beneficial to the entire aircraft design. For example, the surface of the vertical tail was reduced by 17 percent. The only drawback is that it undermines spare parts standardization since there has to be a left-hand gearbox and a right-hand gearbox, left-hand propeller blades and right-hand propeller blades.
The A400M also is equipped with a power gearbox, supplied by Italian-based Avio. Its efficiency is more than 99 percent, Desclaux claimed. A heat exchanger takes out the energy that has not been kept in its mechanical form. Desclaux did not sound concerned about gearbox reliability. “We have performed endurance tests,” he said.
The full-authority digital engine control (Fadec) has been developed according to the latest civil standard. It is innovative in that it controls not just the engine, but also the propeller and nacelle equipment. Its hardware can resist some levels of nuclear radiation.
Asked how EPI has managed to keep such a challenging program on track so far, Desclaux answered that the adoption of civil methods has contributed a lot. He acknowledged that parallel engine testing has increased risk because now it is not possible to make modifications before the next stage of testing begins. “However, we have set up risk reduction actions,” he pointed out. The company tested some critical components very early in the program, he said. For example, it ran the intermediate-pressure compressor (IPC) in November 2004.
According to Desclaux, another factor enabling swift development is that all four partners are highly experienced and are using proven technologies.
The EPI consortium has its headquarters in Munich. Engineering, program and operations, commercial and integrated logistics support (ILS) teams work together in Madrid. The final assembly line is being set up at MTU’s Munich facilities.