“It has a lot of inertia — you can’t remove that. But otherwise there’s no feeling of flying a large aircraft,” says Claude Lelaie, svp of Airbus’ flight division. But that is the point of the A380’s flight control system: to make the aircraft respond as much like other Airbus types as possible, to facilitate cross-crew qualification for mixed-fleet operators. “When the controls are perfectly tuned, you won’t be able to tell if you’re on an A340 or A380.”
Within two weeks of its first flight on April 27, the first A380 had tested the flight envelope to its maximum (Mach 0.89) and minimum operating speeds, to its 43,000-foot service ceiling, and to its normal aft center-of-gravity limit. The envelope had been covered with two sets of control laws: direct law, in which the fly-by-wire system delivers control deflections proportional to stick force, and normal law, in which the aircraft is stabilized automatically and the stick commands attitude. Rolls had been performed at full aft stick by the end of the fifth flight, and emergency systems — such as the ram-air turbine and free-fall extension of the landing gear — had been tested.
“In 22 years at Airbus this is the best flight test program I have ever known,” says Fernando Alonso, vp for flight test at Airbus. “It has gone so well that on flight 13 we invited the EASA flight certification pilot to fly with us.” A dozen pilots have flown the A380 so far, each requiring no more than a single check flight in the right-hand seat before taking over in the left.
“In terms of flight controls it is a piece of cake,” says Alonso, handling just like an A330, A340, or the flight simulator on which its pilots have been practicing for two years. And that is exactly what it was designed to do.
“It is amazing just how good our predictions have been,” adds Alonso, who had flown nine of the test flights by the end of May. —John Morris
By the end of May it had performed a full series of stalls, and on only its 17th flight demonstrated a full autoland. It has already flown in a close three-airplane formation with an A318 and A340-600.
So far, says Lelaie, no surprises. “Comfort and noise at maximum speed are excellent, and there is no buffet with flaps and slats extended. We have a very good feeling about the flight controls: they are not perfect but need only minor tuning.” For example, a slight buzz between the ailerons and spoilers will soon be tuned out.
The flight tests are performed with two pilots and two-to-three flight test engineers, with engineer stations on the upper and lower decks. A third cockpit crew member is carried to help the pilots monitor and manage the aircraft configuration during high-workload tests. Four telemetry ground stations provide coverage of up to 14,000 datapoints on each flight.
The next aircraft to join the test program will be MSN 004, which will be heavily instrumented for performance testing standard empty weight. It should start tests before the end of the summer.
“You don’t know it from another Airbus,” says chief test pilot Jacques Rosay, who made the first flight. “It is easier than the A340 — there is less impression of rotation on takeoff, and the flare seems just the same” with the cockpit a similar height above the ground. The massive wing area allows the A380 to approach at its 512 tonnes maximum landing weight at a stately 140 kts — only 10 kts faster than a tiny A320. And it has already landed at 120 tonnes over that max weight.
“It behaves like a lighter aircraft,” says Rosay. —John Morris
MSN 002 is the next test aircraft in the manufacturing sequence, tasked with testing cabin systems — particularly over long flights. The program will start with one to two months of preliminary tests, followed by four or five “early long flights” carrying a full complement of passengers drawn from Airbus employees. This will allow environmental control systems, in-flight entertainment systems, galleys and lavatories to be tested under real conditions.
After any problems are fixed, MSN 002 and MSN 007, the fourth test aircraft, will be used for 300 hours of route proving. MSN 002 will have a Thales IFE system and 007 will have a Panasonic system. The final test aircraft is MSN 009, which will be dedicated to testing the Engine Alliance GP7200 engine, which is due to be certificated in October. —Bill Sweetman
