Three decades in the making, the multinational Atlas is the first new military airlifter to be developed in Europe since the Transall C-160 twin-turboprop in the early 1960s. The completion of basic development and impending first delivery means Europe has its own heavy-lift transport and customers have an alternative to U.S. and Russian aircraft.
With more than $30 billion invested in development and production, the partner nations have high expectations for the aircraft. Aviation Week was given the opportunity to fly the A400M and assess whether it delivers on the promises made byor is the overpriced political compromise some of its critics allege.
The A400M is sized between the smallerand considerably larger . It is the most advanced and powerful turboprop ever built in the West, with full, three-axis fly-by-wire (FBW) flight controls and the ability to operate from short, soft runways.
The international military airlifter has been a long time coming. The concept was first proposed in 1982, and European requirements were established in 1996. In 1999,Military was formed to manage the A400M program, signing a fixed-price contract for development and production. First delivery was planned for 2009, but development delays forced renegotiation of the contract and the first A400M will now be delivered to the French air force by July.
The A400M received European type certification in March and will enter service with an initial operational capability for logistic missions. Airbus Military is continuing development of military-specific capabilities. The first of these “standard operational capability” releases is planned for year-end, and by the close of 2014 the Atlas is planned to have full aerial-delivery and self-defense as well as aerial-refueling tanker capability.
Airbus Military says A400M can carry a 33-ton payload 2,450 nm and its maximum 40-ton payload 1,780 nm. Normal cruise speed is Mach 0.68, equivalent to 390-kt. true airspeed (KTAS) in ISA conditions at 37,000 ft., the maximum normal cruising altitude for military operations. At average mission weights, the aircraft also will cruise at its maximum operating Mach 0.72 at 31,000 ft., equivalent to 422 KTAS. A typical payload might be 116 paratroops or 66 medevac patients. The A400M also can carry up to nine 463L cargo pallets, twoattack helicopters or three armored personnel carriers.
An optional inflight-refueling package allows the Atlas to refuel helicopters at 105 kt. indicated airspace (KIAS) and fighters at up to 300 kt. Two wing stations can be fitted with 2,650-lb./min. hose-and-drogue pods. A pallet-mounted 4,000-lb./min. hose-drum unit also can be attached to the rear cargo ramp to refuel a third aircraft. With two optional cargo-bay tanks increasing capacity by more than 25,000 lb., total fuel transfer capability is 99,000 lb. at 250 nm. and almost 51,000 lb at 1,250 nm.
The conventional metallic fuselage is pressurized to 7.8 psi and can maintain a sea level cabin to 19,400 ft., and an 8,000-ft. cabin altitude to 37,000 ft. The cargo-bay floor has a track-and-roller system to facilitate loading and unloading. The carbon-fiber wing has a supercritical airfoil with a 15-deg. sweep at quarter chord. The T-tail empennage, also primarily composite, was chosen to keep the horizontal stabilizer above the wing wake.
Most Airbus aircraft systems are loosely based on those of the, but modified for the military mission. The hydraulic system has to two 3,000-psi channels powering the primary and secondary flight-control actuators, landing gear, wheel brakes, cargo door and optional hose-and-drogue refueling system. As with the A380, there is no third hydraulic system. Instead, there are two electrical systems. One is a set of dual-channel electrically powered hydraulic actuators, the other an array of electrically/hydraulically powered hybrid actuators. The dissimilar redundancy provides more protection against battle damage.
The landing gear has 14 wheels for low surface loading on soft runways. There are three independent main-gear struts in tandem on each side and, when parked, these can be adjusted individually to level the aircraft on uneven ground or make it “kneel” to facilitate on- and off-loading.
Aviation Week visited Airbus's main plant in Toulouse to fly the A400M. When I belted into the left seat of MSN6 manufacturer's serial No. MSN6, the final preproduction aircraft used for flight test, Chief Test Pilot Ed Strongman strapped into the right seat as my instructor. He has been with the program since 2000 and flew the A400M on its first flight in December 2009. Experimental test pilot Malcolm Ridley rode along as safety pilot, accompanied by flight-test engineers Jean-Paul Lambert and Thierry Lewandowski.
MSN6 had a 177,250-lb. operating empty weight, about 850 lb. heavier than the baseline production aircraft. With an 882-lb. payload, the zero-fuel weight was 178,132 lb. Partially filled with 55,115 lb. of fuel, ramp weight was 233,247 lb. and computed takeoff weight was 232,365 lb. Maximum takeoff weight for military logistics missions can be as high as 310,851 lb.
We planned to use the's full takeoff rating, 11,065 shp. from each engine (see sidebar, page 40). Based upon using flaps 1, roughly 10 deg., V speeds were 110 KIAS for the V1 takeoff decision speed, 122 KIAS for rotation and 129 KIAS for the V2 engine-inoperative takeoff safety speed. Flap retraction speed was 148 KIAS. V speeds and takeoff field length were computed using a laptop—on production aircraft, they will be calculated automatically by a flight management system (FMS) performance computation function. The FMS also will double-check aircraft weight and center-of-gravity to compute the horizontal stabilizer trim setting for takeoff.
Our flight plan called for departing from Runway 14R at Toulouse, then flying 9.3 nm. southeast to the Toulouse-Blagnac radio beacon. Next, we would descend to 500 ft. above ground level (AGL) and fly low level to Garonne intersection near Noe and then on to Cazeres in the foothills of the Pyrenees. Weather permitting, we then would fly low-level eastward along the foothills for about 20 mi., pull up to medium and high altitudes for handling and cruise performance checks, then return to Toulouse for pattern work.
The weather was almost ideal for a demonstration flight. There were plenty of cloud layers starting below 1,000 ft. and going all the way to 25,000 ft.-plus. This would enable us to evaluate the aircraft in the low-visibility conditions in which it is designed to operate.
Strongman used the checklist on the electronic centralized aircraft monitor display to complete the pre-start checks. Firing up the engines was easy. We turned on the fuel pumps, rotated the engine start knob and then toggled the engine master switch from off to feather. The full-authority digital engine controls handled all other starting functions, including malfunction protection.
During start, as each feathered prop began to accelerate to 180 rpm, vibration was palpable. But after the engines had stabilized and we moved the master switches from feather to run, vibration all but vanished as the props sped up to a 650 rpm ground idle.
Releasing the parking brake, idle thrust barely moved the aircraft. We had to advance the power levers to start taxiing, but once rolling the aircraft accelerated. Strongman suggested modulating the power levers for inboard Engines 2 and 3 from beta range or even partial reverse and back to ground idle to control taxi speed. The carbon brakes were smooth, as was the nosewheel steering.
We lined up on Runway 14R. When cleared for takeoff, we rapidly advanced the thrust levers from flight idle to the forward stops. The engines smoothly accelerated and the props stabilized at 860 rpm, producing moderate noise in the cockpit. I recommend active noise-attenuation headsets, but judge takeoff noise levels in the cockpit to be far below those encountered in aor most other turboprops.
With a 5.25:1 weight-to-power ratio, aircraft acceleration was brisk, but smooth. For rotation, we pulled back about halfway on the sidestick and released it when the nose came up to 20 deg. The fly-by-wire system's flightpath stability function maintained the commanded pitch and wings-level bank attitudes as the aircraft accelerated and we retracted landing gear and flaps.
As the altitude alert sounded, signaling our approach to the 3,000-ft. initial clearance altitude, we pulled the power levers back to the managed thrust detent, ceding control of the engines to the auto-throttle system, which slowed prop speed to 730 rpm and reduced power to about 9,460 shp for climb. The slower prop speed greatly reduced cockpit sound levels.
As with Airbus jetliners, the A400M's power levers are not back-driven. They remain frozen in position at the managed power detent. In my opinion, moving power levels provide flight crews with useful visual and tactile cues to the auto-throttle functioning.
We leveled off at 3,000 ft. and 250 KIAS and selected the engines' low noise-contour operating mode, reducing prop speed to 650 rpm to minimize aircraft sound profile over hostile territory. It also minimized the noise footprint over civilians in Toulouse.
Using the flightpath vector symbol on the head-up display (HUD) and taking advantage of the FBW flightpath stability function, it was easy to hand-fly the aircraft and maintain heading and altitude. Minor inputs to the side stick were all that was needed to make small corrections to the flightpath.
Nearing Toulouse-Blagnac, we found a hole in the clouds, banked sharply to the right, dived to 500 ft. AGL and accelerated to 280 KIAS as we headed for Garonne. There was plenty of low-altitude turbulence from a large storm in the vicinity, but the flightpath stability function made the aircraft easy to control.
Modifications to the civil Airbus FBW system make the A400M agile for such a large aircraft. Control response to vigorous sidestick inputs was crisp, but also well damped so there was no tendency to overshoot when the sidestick was released. Virtually no rudder inputs were needed to maintain balanced flight. The radio altimeter provided synthesized-voice call-outs of our height above ground, reducing the task of maintaining the desired 500 ft. AGL low-altitude cruise.
We switched on the forward-looking infrared enhanced vision system (EVS) camera to enhance our view of the terrain in the low-visibility conditions. Strongman held up a card in front of the left HUD to obscure my view of the outside world through the combiner glass. It was easy to use the EVS imagery on the HUD to fly at low altitude, demonstrating its value for flying tactical missions at night or in clouds.
Approaching Cazeres, the weather closed in, so we executed a maximum-performance climb by pushing the thrust levers forward to the stops and pitching up to 40 deg. Initial climb rate was in excess of 7,000 fpm and we quickly topped the low-level cloud layers.
We continued the climb at 230 KIAS to flight level (FL) 310 for cruise performance checks. At a weight of about 227,000 lb., the aircraft cruised easily at Mach 0.68 while burning 7,700 lb./hr. of fuel. In ISA-5C conditions, cruise was 394 KTAS. Accelerating to the aircraft's Mach 0.72 redline, fuel flow increased to 9,100 lb./hr. Cruise speed was 417 KTAS in ISA-5C.
Descending to 12,000-16,000 ft., we flew a series of standard maneuvers that yielded impressive results. At 280 KIAS, we could roll into a steep bank, pull all the way aft on the sidestick and the aircraft would smartly snap into a 3g turn with no threat of overstress, thanks to the FBW flight-envelope protection.
High angle-of-attack (AOA) behavior was similarly impressive. The fly-by-wire system is programmed to recognize the difference in wing performance due to the lift generated by prop wash. This could be seen during power-off and power-on maneuvers to “alpha max,” the maximum AOA allowed by the FBW system's normal control law. Alpha max is programmed to be just slightly below the stalling AOA. It provides high lift-coefficient wing performance at full aft stick and also full controllability.
Strongman demonstrated an additional layer of stall protection. With the auto-throttle armed, the system intervenes with “speed floor” protection by increasing thrust long before the aircraft approaches alpha max.
We then disabled the speed floor and explored aircraft handling at alpha max. At a weight of about 225,000 lb. and with flaps 4 selected, we pulled the thrust levers back to idle and maintained altitude, causing the aircraft to decelerate. With full aft stick, we reached alpha max at 98 KIAS. At that point, the FBW low-speed protection function eased the nose down. There was no wing roll-off or loss of control. Recovery was almost immediate when we lowered the nose and added thrust.
We then repeated the alpha max maneuver, this time after setting maximum climb power. We continued to increase nose attitude to slow the aircraft at about 1 kt./sec. with each engine producing about 7,900 shp. With the stick all the way aft, the aircraft decelerated to 78 KIAS before the FBW system eased the nose down at alpha max, again with no loss of control or composure.
The power-on approach to stall proved that the aircraft can be flown at 105-120 KIAS with flaps 4 for helicopter aerial refueling. We comfortably flew the aircraft at 110 KIAS at flaps 4 during the demo flight.
The fly-by-wire system also takes away most of the pilot workload associated with handling engine failures. At 13,000 ft., we set 100% power at 121 KIAS, pulled the outboard Engine 4 power lever to idle and watched as the FBW system compensated with aileron and rudder inputs to keep the aircraft in balanced flight. When both right Engines 3 and 4 were pulled back to idle and both left engines were at 100%, the FBW system maintained balanced flight. We needed only a slight left bank and nose-up attitude to climb the aircraft on heading at 121 KIAS and flaps 4.
After the air work, we returned to Toulouse for a normal, 3-deg. glidepath instrument landing system (ILS) approach to Runway 14R. Computed VREF landing speed for flaps 4 was 120 KIAS at a weight of about 222,000 lb. We added 5 kt. and bugged 125 kt. for the final approach speed.
Unlike a conventional Airbus, the A400M uses a decelerating speed schedule on final approach. The auto-throttle system does not completely slow the aircraft to VREF until it nears the threshold. The speed changes are not easy to notice because of the FBW's flightpath stability function.
We completed the first approach with a touch-and-go landing and turned onto a visual-flight-rules downwind pattern to the south. Just past abeam with the runway approach end, we turned a close-in base leg at 3,000 ft. AGL, 2,500 ft. above the airport. We extended the landing gear and flaps 4, maintaining altitude and 148 KIAS until we were 3 mi. from the threshold.
At that point, we reduced power, fully extended the speed brakes and began a 12-deg. plunge, simulating an assault landing. The aircraft was easy to control and the 3,000-ft./min. descent rate felt comfortable. At 500 ft. above the runway, we retracted the speedbrakes, increased thrust and transitioned to a normal 3-deg. ILS glidepath while slowing to 125 KIAS. We crossed the threshold at 60 ft. and began to pull back the thrust levers. Touching down just beyond the stripes, we flew the nose down to the runway, pulled back fully on the thrust levers and braked heavily. The aircraft stopped in about 1,600 ft. With practice, the landing roll could be shortened considerably.
For launch customers Belgium, France, Germany, Luxemburg, Spain, Turkey and the U.K., plus Malaysia, the A400M fills a niche below the C-17. As a strategic airlifter, it has more speed, range and payload than the C-130J, but less than the C-17. As a tactical airlifter, it has a steep-approach assault landing capability that no other Western heavy-lift transport can match. It can operate autonomously at austere airstrips with unimproved runways and unleveled ramps.
First delivery to the French air force is set for next month, to be used for military qualification. Two more are planned to be delivered to the French and one to Turkey by year-end. Production rates should increase in 2014 and beyond, depending upon European defense budget allocations. Longer term, because it is a European product with atype certificate, the A400M could attract customers that do not want to buy U.S. or Russian products for political reasons.
The Atlas has some of the most capable avionics and flight controls ever fitted to a military transport. Its turboprop engines are unprecedented for their blend of power and fuel efficiency. This agile performer feels more nimble than older heavy-lift transports. But it is pricey. Divide the number of orders by the total investment and the unit price is a staggering $170 million-plus—almost twice the cost of a C-130J.
But even if the eight announced customers remain the sole users, the aircraft may yet prove its worth. With near-jetliner cruise speed, the A400M may be the fastest way to transport troops, arms, fuel and supplies to unimproved landing strips close to the front lines, and to rush casualties back to top-tier emergency medical facilities.
Fly along with Fred George in the A400M to see the transport's performance and features at ow.ly/lJfeV
|Seating||3 crew + 116 troops|
|Engine||4 x EPI TP400-D6|
|Output (ISA)||11,065 shp each|
|Wing Loading||130.4 lb./sq. ft.|
|Power Loading||7.02 lb./shp.|
|Operating Weight Empty||176,400/80,015|
|Troop Payload — 116 @ 300 lb.||34,800/15,785|
|Max Fuel without cargo hold tanks||110,704/50,215|
|Payload with Max Fuel||24,628/11,171|
|Fuel with Max Payload||56,882/25,802|
|Fuel with Troop Payload||100,532/45,601|
|Vmo/Flight Level||300 kt./FL 245|
|Sea Level Cabin||19,400/5,913|
|Sources: Airbus Military, EASA and AW&ST|