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Tuesday, July 1, 2003

Airbus A400M

After years of waiting, the on-again, off-again Airbus Military A400M program finally has taken wing. The European transport–aimed at the market for aging Lockheed Martin Hercules aircraft–will incorporate avionics technologies developed for t

Charlotte Adams

Airbus Military’s A400M airlifter program – finally launched after years of waiting, wrangling and political drama – will go head to head with the C-130J and stretched C-130J-30 for export orders. Will the A400M’s new avionics systems and other innovations power the newcomer beyond its base market in Europe? Will new technology drive life cycle cost to the C-130J level, as claimed? A tall order – but one Airbus believes it can achieve.

The May 27th contract between Airbus Military S.L. – an Airbus subsidiary – and the joint European military procurement agency moved the 20-billion-euro ($23.7-billion) program into a more than six-year, single-phase development and production effort. Major avionics contracts are expected by next June and U.S. as well as European suppliers are likely to participate. Seven countries–Germany, France, Spain, Great Britain, Turkey, Belgium and Luxembourg–have ordered 180 of the fly-by-wire, dual-sidestick-controlled airplanes, Italy and Portugal having earlier withdrawn from the project.

Airbus Military, which manages the project, eyes an export market for more than 200 A400Ms over a 20-year period: Australia, Norway and Sweden are near-term prospects. Japan and South Africa also are mentioned. In competition with the C-130J, the aircraft could replace aging C-130 Hercules and C-160 Transalls worldwide, the company says. Airbus also positions the A400M against Boeing’s C-17, as better meeting Europe’s transport needs at far lower acquisition and life cycle cost. The current price estimate is about 71.6 million euros ($85 million) for the "standard common aircraft," as delivered, without options. The basic C-130J, by contrast, sells "in the 60s," according to Lockheed, which asserts that the A400M is not a competitor in the tactical realm. The A400M claims a range of 2,450 nautical miles (nm) for a load of 30 tonnes (67,200 pounds) and 3,550 nm for a load of 20 tonnes (44,800 pounds).

The A400M contract is an "extremely critical step," says John Pike, director of Globalsecurity.org, a defense policy research group. "I have no doubt that eventually, [the A400M] will be a fine airplane for the European military. Whether it will be anything more is why everybody is watching it." Airbus will have a "substantial learning curve, getting a workable design and getting [countries like] India, Nigeria and Argentina to replace existing aircraft and maintenance capabilities with a new and unfamiliar product." Ukranian plane maker Antonov, with its An-12 base, has a leg up, as well, Pike says. "[The A400M] could be not much more than a technological curiosity or it could completely remake worldwide military airlift."

Starts and Stops?

From its beginnings in the mid-1980s as the Future Large Aircraft (FLA), the project has alternately sped forward or halted, as situations changed. The latest obstacle–a flap over the engine contract–was resolved this spring, as Airbus Military selected EuroProp International rather than Pratt & Whitney Canada to supply the plane’s four turboprops. Barring further problems, the first plane would fly in 2008, be delivered in 2009 and enter service in 2009. First on the receiving list is France, followed by Turkey, the UK and Germany. The program had been dangling since December 2001, as the initial contract was contingent on German approval. The German parliament’s defense budget committee finally approved 8.3 billion euros in funding for 60 airlifters, down, however, from the 73 aircraft originally planned.

Just as the A400M’s wings are under British leadership and the fuselage, under German management, the flight deck is the responsibility of Airbus France. Avionics contracts still are pending, but Airbus Military was able to discuss cockpit and avionics systems on a general level. Flight avionics, for example, are baselined on the A380, with modifications and additions for military operations, says Sergio Llamazares, A400M systems manager in the Airbus program office. Use of A380-based avionics will leverage Airbus’ investment in the super jumbo and enhance the reliability and efficiency of military airlift, advocates contend. The A400M’s non-military avionics and operations, such as logistics, will be certified through civil authorities for export purposes.

The military side will use off-the-shelf systems with the exception of a terrain masking low-level flight (TMLLF) system required by Germany, a military mission management system (MMMS), and a defensive aids computer (DAC). Integrating military and civil systems and making them easy to access, operate and control in combat will challenge human machine interface (HMI) designers. (For more on the A380, see March 2003, page 26.)

"At the end of the day, we have to implement a lot more functionality from the military world [in addition to baselined A380 flight avionics]," Llamazares says. "We know we have to manage the pilot interfaces and pilot workload quite carefully." This situation drives maximum HMI interactivity and consolidation.

"We intend to build from the actual design of the A380," says Bruno Darboux, head of the A400M Cockpit Component Management Integrated Team. From an architectural point of view, the airlifter will use the A380’s 100-megabit/sec avionics full-duplex (AFDX) switched Ethernet flight data communications network, Ethernet onboard file server, and the A380’s integrated modular avionics concept.

The A400M also will be capable of reconfiguration as a tanker with two refueling points on the wings and one system in the rear of the cargo area, called the hose drum unit (HDU). Structural provisions will be made for these elements. This configuration also offers up to three optional video cameras to enable the crew to monitor–day and night–the refueling process from underwing pods and the central HDU.

Flight Deck

The A400M is expected to use the same type of 6-by-8-inch LCD displays supplied by Thales Avionics to the A380, employing the ARINC 661 protocol to standardize interactivity management and the same electronic centralized aircraft monitoring (ECAM) system. Performance is guaranteed with a two-member flight crew, but an optional, forward-looking third crew station with a multifunction display and controls is planned. The third crewmember will have access to the overhead panel and "can do everything except fly," says Darboux. The removable extra crew station, located just behind the center pedestal, will allow close crew coordination and offload communications and countermeasures tasks during demanding instrument meteorological conditions (IMC) and low-level flight operations.

Airbus plans to implement dual, wide field-of-view (typically 35-by-26-degree), raster-capable head-up displays (HUDs), which will be certified as primary flight instruments. Forward-looking infrared- (FLIR) based enhanced vision system imagery will be overlaid on the HUD to help pilots peer through cloud, rain or darkness, enhancing situational awareness. Tactical information, such as defensive aid subsystem (DASS) tracks/alerts and optional multifunctional information distribution system (MIDS) data link information also may be displayed. Airbus is considering LCDs for the HUDs, but that does not preclude other solutions.

The HUD’s main parameters are: pitch and roll, heading, actual/potential flight path angle, track, selected/actual speed and altitude, radio altitude, air dropping guidance, landing aids and high-priority messages, such as threat, decoy, warning and terrain. Lighting for the entire cockpit and cargo area will be night-vision compatible.

Interactivity and Consolidation

Because the A400M’s cockpit is much smaller than the A380’s–and the aircraft adds military self-protection, communications, navigation, surveillance and data link systems–greater consolidation of functions and more interactivity are required.

Each pilot has a primary flight display (PFD) and a navigation and tactical display (NTD) pair, located at the left and right of the front panel. An engine and warning display, in the center, will be shared by both pilots. The PFD can be configured as a nav display and vice versa. The PFD will display the same data as the HUD, plus autopilot system mode annunciation and still-to-be-defined secondary information. Pilots will interact with the displays through a multipurpose keyboard (MKB) and a cursor control device. As of late May, Airbus was using the A380 MKB and cursor control device in HMI tests.

Airbus expects to present a topographical map display with flight plan overlay on the NTD. A tactical, vertical position and terrain display can be selected in the lower, 2-by-6-inch area of the screen, with forward distance along one axis and altitude along the other. The vertical position display will be a "tactical, short-term display that focuses on low-level flight," Darboux says. The A400M will be able to fly to 492 feet above ground level in IMC. Threat symbols, coordinates and bearings, plus text notations, will appear on the NTD.

A400M pilots will be able to graphically overlay tactical information on the NTD, such as threat corridors–the designated areas where aircraft can remain out of range of particular threats–and drop zones. The nav display also will present a God’s eye weather radar picture and formation keeping system (FKS) information. Finally, it will show video feeds from TV cameras in the cargo bay and under the wings–in the tanker configuration–for cargo and refueling surveillance. The A400M FKS will be compatible with the AN/APN-243A system developed by U.S.-based Sierra Research.

The NTD’s tactical display format fuses data from the defensive aids subsystem and the MIDS data link, allowing the presentation of correlated and consolidated threat information. "The key point in this display is to make the pilot aware of the mission scenario–threats and non-threats," Llamazares says. So data fusion, decluttering, symbology and color coding are important.

The A400M will have a permanently displayed "mail box" for the crew to interface to the MIDS–including Link 16– and an optional FANS A data link. Potentially, the area for receiving, entering and sending military and civil data link messages could be displayed in the lower, 2-by-6-inch window of the MCDU. Such an interface may not be implemented, however, as military messages may need a more visible position in the cockpit.

The defensive aid subsystem, which controls aircraft countermeasures, will evolve in two steps. Step 1 includes the DASS computer, the radar warning receiver (RWR), passive missile warning system (IR or ultraviolet), and the chaff/flare dispensing system. Aircraft will be fully provisioned for these functions. The second step will include the laser warning receiver, direct energy IR countermeasures (DIRCM) system, towed radar decoy (RF jammer and spoofer, or techniques generator), and active missile warning system. Structural provisions will be made for Step 2 systems, including power, space available and any required structural modifications.

Opting for Military Radar

The baseline standard common aircraft requires a weather radar with turbulence/ windshear detection and ground mapping. But some European nations want the option to introduce a military radar instead, Llamazares says. Although its modes have not yet been defined in detail, the military radar will have performance equivalent to the Northrop Grumman AN/AP-241 low-power, color weather/navigation radar. That system, which is installed on C-130J and C-130H transports, incorporates Doppler ground mapping mode, air-to-air skin paint mode, and windshear mode.

Three years ago Northrop announced a memorandum of understanding with DASA–now part of EADS–on the definition and expansion of business arrangements for the production and support of the AN/AP-241 radar for the European transport. A letter of agreement to move forward on the relationship was signed last October, but, as of late May, no contract had been signed. Airbus will provide structural provisions for the military radar.

Other surveillance functions, according to the current baseline, will be distributed into separate avionics boxes, rather than grouped together in a single enclosure, following Airbus’ pre-A380 practice. The A380’s aircraft environment surveillance system (AESS), to be provided by Honeywell, packages the weather radar, traffic alert collision avoidance system (TCAS), terrain warning and Mode S transponder together and integrates the assemblies at the data level. An AESS-type approach has not yet been excluded, but if it is used, data from the identification friend or foe (IFF) function would have to be shared with AESS components.

Systems Control

Use of "soft" controls–virtual control panels located in windows on the screens–will be much more intensive on the A400M than on the A380, to compensate for the lack of space for conventional control panels. The mockup NTD display (top, right) shows the lower 2-by-6-inch window filled with four rows of soft controls–six buttons per row.

Although nothing has been set in concrete, the idea is for pilots also to interact with the flight management system (FMS) by way of the NTD, as well as through large-format, multipurpose control and display units (MCDUs) located, as in the A380, on the center pedestal. Waypoint redesignations, for example, can be implemented directly on the moving map/flight path display. With this interactivity concept, pilots will be able to "drag and drop" waypoints on the graphical representation of the flight plan, with distances and fuel requirements recalculated automatically. This approach would simplify the task of en route flight replanning, "particularly during low-level flight phases, where quick crew reaction to unplanned events is of paramount importance," says Llamazares.

The two 6-by-8-inch MCDUs provide a single interface to the FMS–also baselined on the A380–and the military mission management system. (The FMS and the MMMS are powered by two distinct computers, each with a backup.)

Navigation, video, communications and synoptics–including self-defense, cargo, air-to-air refueling and platform (non-military) systems–may be accessed through the MCDUs. These displays also are used for some cargo handling/delivery and refueling functions, as well as to access and control the optional digital terrain referenced navigation (TRN) system and a terrain masking low-level flight system required by Germany for its aircraft. Basic low-level flight functionality will be standard on all A400Ms.

As of late May, Airbus planned to integrate specific TMLLF guidance laws into the flight control system, which will be based on commercial equipment. The FMS will establish the aircraft’s three-dimensional position by fusing information from the inertial reference system (IRS), GPS and TRN. The TRN then computes an aircraft position by terrain correlation, using the radar altimeters and a digital terrain database stored in memory to identify and remove IRS drift errors.

The MMMS will control cargo handling and delivery, calculating the load plan and the computed air release point before an air drop, as well as fuel management and fuel operational ranges. The MMMS also will manage the Mil-Std-1553 data buses and the tactical ground collision avoidance system (T-CGAS). The T-CGAS is similar to EGPWS but is specific to tactical, low-level flight operations. The MMMS also will manage military/civil communications, including Tacan (tactical air navigation) tuning and radio auto-tuning. T-CGAS will have functionality equivalent to that of BAE Systems’ TERPROM (terrain profile matching) system. TERPROM provides terrain-referenced navigation, ground proximity warning, obstacle warning, terrain following and passive target ranging.

The MMMS also will convert data from the Mil-Std-1553 buses–integrating communications functions, DASS and MIDS–to the format used by the AFDX avionics backbone bus, so that data can be shared between the various systems. At press time, load analysis was under way to determine the number of 1-MHz 1553 buses that will be required.

Selected Avionics Systems


  • Radios: HF, VHF and UHF, Selcal (selective call) and optional Inmarsat satcom,

  • Audio: audio management system, wireless intercom, cockpit voice recorder, passenger address system,

  • Emergency locator transmitters (ELTs),

  • Communications security equipment (voice encryption/decryption, data encryption/decryption, and frequency hopping),

  • Data Links: optional MIDS (multifunctional information distribution system) and optional FANS A (future air navigation system), and

  • Identification: identification friend or foe (IFF), Mode S transponder


  • Weather radar with turbulence/windshear detection and ground mapping,

  • Optional military radar,

  • Traffic alert collision avoidance system (TCAS),

  • Enhanced ground proximity warning system (EGPWS),

  • Optional tactical ground collision avoidance system (T-GCAS), and

  • Optional formation keeping system


  • Three inertial reference systems with embedded air data systems,

  • Two military GPS receivers,

  • Navaids with auto-tuning: VOR, DME, Tacan (tactical air navigation),

  • Optional automatic direction finder (ADF),

  • Multimode receiver with ILS, microwave landing system (MLS) and two civil GPS receivers,

  • Two radar altimeters,

  • Optional digital terrain referenced navigation (TRN) system, and

  • Optional terrain masking low-level flight (TMLLF) system

Flight/Mission Management:

  • Two flight management system (FMS) computers and

  • Two military mission management system (MMMS) computers


  • Two foldable, wide-angle HUDs,

  • Seven 6-by-8-inch head-down displays, including two MCDUs (multipurpose control and display units), and

  • One optional MCDU and controls for a third crew station

Defensive Aids Subsystem (DASS)

  • Central processor,

  • Radar warning receiver (RWR),

  • Passive/active missile warning systems,

  • Chaff/flare dispensers,

  • IR detection systems,

  • Direct energy IR countermeasures (DIRCM)

  • Laser warning system, and

  • Towed radar decoy

A400M Acronyms

  • ADF - automatic direction finder

  • AFDX - avionics full-duplex (switched Ethernet)

  • DAC - defensive aids computer

  • DASS - defensive aids subsystem

  • DIRCM - direct energy IR countermeasures

  • ECAM - electronic centralized aircraft monitoring

  • EGPWS - enhanced ground proximity warning system

  • FKS - formation keeping system

  • FLA - Future Large Aircraft

  • FANS - future air navigation system

  • FLIR - forward-looking infrared

  • FMS - flight management system

  • HDU - hose drum unit

  • HMI - human machine interface

  • HUD - head-up display

  • IFF - identification friend or foe

  • IRS - inertial reference system

  • MCDU - multipurpose control and display unit

  • MIDS - multifunctional information distribution system

  • MKB - multipurpose keyboard

  • MLS - microwave landing system

  • MMMS - military mission management system

  • NTD - navigation and tactical display

  • PFD - primary flight display

  • RWR - radar warning receiver

  • Tacan - tactical air navigation

  • TCAS - traffic alert collision avoidance system

  • TERPROM - terrain profile matching

  • T-GCAS - tactical ground collision avoidance system

  • TMLLF - terrain masking low-level flight

  • TRN - terrain referenced navigation

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