Some thought that it would never fly, while others believed that development issues and programme delays would lead to its cancellation. But Airbus Military's A400M will make its long-awaited first public appearance at this month's Berlin air show, with the manufacturer intent on showing its European customers that their continued commitment to its flagship product will be rewarded.
The A400M should have debuted at ILA two years ago under previous plans, but its historic first showing will still be well placed, given Germany's status as the largest single customer for the type.
Berlin's stake in the project accounts for one-third of the 180 aircraft ordered in a May 2003 contract signed by the governments of Belgium, France, Germany, Luxembourg, Spain, Turkey and the UK via Europe's OCCAR procurement agency.
Germany has ordered 60 of the 180 A400Ms commissioned at the programme's launch in 2003. Picture: Airbus Military
To replace its air force's Dassault-Breguet C160 Transalls, Germany's 60 A400Ms were originally scheduled to be delivered to Wunstorf air base from this year. However, this schedule has slipped by around three years, so the venerable twin-turboprop will have to soldier on for some time.
Highlighting the nation's programme standing, a German officer also recently became the first non-Airbus pilot to fly an A400M. Drawn from a multinational test team that will support military certification activities, the pilot "was really impressed", says Airbus. Representatives from the European Aviation Safety Agency were due to fly the aircraft for the first time in late May.
German industry is also heavily involved in the A400M project. The aircraft's fuselage is delivered to Airbus's San Pablo final assembly line near Seville, Spain via A300-600 Beluga from Bremen. The nation also hosts the assembly of the aircraft's Europrop International TP400-D6 turboprop engines at MTU Aero Engines' Ludwigsfelde site. Vertical tailplanes are delivered from Stade, while the programme's fatigue test aircraft is in Dresden.
However, the German air force's A400M fleet now appears likely to be reduced slightly as Berlin looks to balance the effects of a major overrun to the previously fixed cost of developing and producing the type.
Agreed at €20 billion ($24 billion), this figure has now been increased by at least €4.3 billion under an in-principle agreement reached by the EADS-led company and its customers on 5 March.
Saving the programme from possible cancellation, the launch nations agreed to pay a combined €2 billion more for their aircraft, waive all liquidated damages linked to the delay and to invest a further €1.5 billion in support of Airbus's efforts to export the A400M. The company has also made its own financial provisions as part of the deal.
As part of the agreement, Airbus offered its customers the option to cancel up to 10 aircraft from the original 180. Germany is believed to be keen on removing seven A400Ms from its order, with the UK having already confirmed its intention to reduce its 25-strong commitment by up to three.
In addition to potentially stripping some aircraft from its order, Berlin has also instructed Airbus Military to abandon some of its unique configuration requirements. These include a sophisticated terrain-following navigation system that was being developed by EADS Defence Electronics uniquely for the German air force.
Germany has deleted a requirement for its A400Ms to have a terrain-following navigation system. Picture: Airbus Military
"We have an agreement with the German customer to stop that one," says Airbus Military managing director Domingo Ureña. "Everybody understands the economical situation," he adds. "We all need to make efforts, and we opened the door with these  aircraft."
Ureña says the company and its customers have shown a "willingness to conclude as soon as possible the formalisation of the agreement. Our target, which we still consider to be feasible, is to have everything ticked, and final approval by the governments before the end of the summer."
Meanwhile, a dispute with engine supplier Europrop over its role in programme delays is being resolved. "We've stopped to claim against each other," Ureña confirms. "Common sense indicated to the two companies to start a process to constructively resolve our problems. We are married for a long time, and divorce is not allowed."
However, relations with Thales are still at a low, and this situation with a major supplier "is the real concern at this moment of the programme", he says.
When Ureña took the helm at Airbus Military in February 2009, the Spanish official was faced with guiding the company through a potentially traumatic integration with Airbus from EADS's Military Transport Aircraft division, while also ensuring that the A400M flew before the end of the year.
With the integration activity having concluded on 1 January, Ureña says the benefits are already evident. "Now, nobody has doubts that we are only one company, as part of Airbus," he says. "We try to share the skills of engineering, production, systems and tools. Our customers are starting to appreciate the value."
With a new contract to place the A400M in a stable position, Ureña says Airbus is committed to "deliver the aircraft fulfilling the guarantees that we have with the customers. The A400M is not capital, it is strategic," he adds.
Ureña says that the European aerospace industry faces a significant near-term challenge, as nations look to reduce their military procurement budgets and place increased support on operations such as those in Afghanistan. However, he believes that positives can still be drawn.
"I am convinced that in difficult times we have more opportunities. It's very easy to make business when everybody has plenty of money," he says.
Airbus has identified a potential market to sell 350-500 more A400Ms to international customers, says senior vice-president commercial Antonio Rodriguez-Barberán. Two potential new air force customers have visited Spain within the last several weeks, but he declines to name them.
Malaysia is the only such buyer for the design, and will receive four. South Africa late last year cancelled its eight-strong order, just weeks before prototype aircraft MSN001 made its first flight on 11 December.
Airbus is assessing its long-term ties with South African industry, but with more than €300 million of its own money already invested in local companies it has decided against removing existing work packages. However, it recently rejected one re-bid proposal from Denel Saab Aerostructures.
"We try to engage in dialogue with the customer, and hope that they will reconsider the decision," says Ureña. "Sooner or later, South Africa will need the A400M," he believes.
Ed Strongman, Airbus's chief test pilot military, hopes to encourage wider market interest in the transport by displaying MSN001 at ILA on 8 and 9 June. The company cannot commit to a longer stay to keep momentum with flight testing, but will "demonstrate the full capabilities of the aircraft", he says.
Tests involving MSN001 and MSN002 - both of which carry heavy instrumentation loads weighing around 17t - had reached 165 flight hours and 44 sorties by 20 May.
Recent milestones have included the completion of stall testing without the need to use an emergency booster recovery rocket, which has now been removed from MSN001.
"We approached our first stall with a lot of attention, but it was a piece of cake," says Strongman. The crew encountered buffeting only within around 1° of reaching the stall angle, and the pilots retained full roll control throughout the manoeuvres.
"It's a remarkable aeroplane," he says. "It has as good, or better handling qualities than an A320." He attributes this partly to the A400M's counter-rotating propeller configuration, which adds to its stability under such conditions.
Stall testing was conducted between idle and full power and with forward, centre and aft centre of gravity loadings, and at altitudes between 32,000ft (9,760m) and 10,000ft.
Strongman declines to identify the angles of attack achieved before the stall, but confirms: "The alphas were as predicted, and in some cases higher."
The test team is establishing where limits exist, and the A400M's envelope protection will prevent operational crews from encountering potentially dangerous conditions.
This process also included demonstrating the A400M's impressive maximum lateral roll rate. Airbus is required to certificate its roll protection at 90°, but says it will instead offer 120°. Strongman says the test actually demonstrated an angle of 124° due to an incorrect stick input, but adds that this was still "well within the range of the aeroplane. It was Friday night and it was 8 o'clock, but it was good," he adds.
The aircraft during April underwent testing at Istres in southern France to assess its handling characteristics in ground effect down to just 15ft above the runway. "We were just on the limits of turbulence also, so it was a really good simulation," says Strongman.
Full sideslip and load factors testing have been completed, the aircraft has been operated across its stress range of +2.5g to -1g, and its doors and cargo ramp have been opened in flight at between 120kt (222km/h) and 200kt without affecting handling characteristics.
A maximum altitude of 34,000ft has been achieved, and the A400M was due to be taken to its VD velocity limit, and to perform flutter validation flights in late May. At this point, a major restriction to testing can be lifted, with stress gauges to be removed from the TP400's Ratier-Figeac propeller blades. This will enable the flight test team to fly the A400M through clouds and rain for the first time.
In an unusual parallel with a past programme, Strongman says that during some flight conditions and angles of attack at higher altitudes, the A400M exhibited a slight snaking motion. Experience within Airbus likened the characteristic with the Transall, and adopted the same solution. Strakes added to the main landing gear sponsons now act as vortex generators, and Strongman says the trait has not been encountered on any subsequent flights.
Other earlier issues from flight testing are in the process of being addressed, such as to fix a landing gear overheating issue. More work will be performed to define braking limits and to perform rejected take-offs. A new high power mode full authority digital engine control software load for the TP400 has also recently been tested on one engine, and will soon be expanded to all stations.
Although flight-test activities got off to a slower than expected start, because of unusually bad weather in Seville and Toulouse over the winter months, MSN001 in mid-May for the first time flew twice in one day.
"The whole process is accelerating," says Strongman, who describes the transport as intuitive and easy to operate.
"Every pilot has a smile on his face, due to the A400M's handling and manoeuvrability," Strongman says.
MORE A400MS POISED TO JOIN FLIGHT TESTING
In late May, MSN003 was in the midst of securing clearance to fly in "early summer". Picture: Airbus Military
With the A400M programme's first two prototype aircraft now being flown regularly in France and Spain, Airbus Military is preparing to double the size of its test fleet within the next six months.
Due to fly in the "early summer", MSN003 was in late May undergoing final clearance tests on the company's San Pablo final assembly line near Seville, and will soon be transferred to its flight-test department at the site.
To be employed for systems testing from Toulouse, the aircraft has several modifications made following the lessons learned in early flight-testing. These include the addition of small strakes on the main landing gear sponsons and a lower auxiliary power unit exhaust chimney.
Aircraft MSN004 is in the general joining stage at San Pablo and was scheduled to undergo power-on for the first time in the last week of May. First flight is planned before the end of the year.
All major components for the remaining flight-test example are in production and final assembly work will start in the third quarter of this year. The first A400M to be built to a series production standard, MSN006 will have weight reduction modifications and other system upgrades.
Parts are also being produced for the programme's first customer aircraft, which should be delivered to the French air force in December 2012. The San Pablo facility is expected to complete 2.5 aircraft a month by 2015, against a peak of three a month.
"Production is working smoothly and we think we are on the way to success," says Rafael Nogueras Cebrero, head of the A400M final assembly line and flight-test centre.