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.