September 09, 2013
The first Airbus A350 entered the preliminary flight-test phase on June 14, and made its much publicized flyover at the Paris air show only one week later. Now the initial part of the flight-test campaign is drawing to a close.
Airbus expects to be able to freeze the final configuration for flap settings in various flight phases, including takeoffs, approaches and landings, within 4-6 weeks. Once the optimum configuration has been determined and validated against simulation data, the manufacturer will have passed a crucial milestone, which heralds the start of the actual certification testing later this year.
MSN001 resumed its test program on Aug. 15 following a planned break in the schedule to allow for more test equipment to be installed. Additional instrumentation was added to measure loads, and more cameras were put onboard. As of last week, the aircraft had logged more than 150 flight hours and was flying almost daily. This amount of test hours is at the upper limit of expectations, according to Airbus officials.
Following the temporary break, the average flight times have regularly exceeded 6-7 hr. When the aircraft made its debut at the Paris air show, that excursion was included in a test flight that exceeded 9 hr.
Last week, Airbus CEO Fabrice Bregier became one of the first non-test crew to fly onboard the A350. The sortie he was on flew close to 4 hr. Not surprisingly, Bregier promptly announced that he liked the smooth ride and was impressed by the large flat-panel screen displays in the cockpit.
Having initially devoted most of the time to open the full flight envelope (all expected speeds and altitudes), MSN001 is now mainly undergoing performance testing at various configurations (flap settings) to determine the best angle for each setting in a trade-off between lift and drag. While most settings will be identical for takeoff and landing, the slats setting in “position flaps 3” will be slightly different, according to Patrick du Che, head of flight-test development. Data generated in the tests is used to run a series of models to determine the optimum configuration.
The minimum unstick speed test, or VMU (velocity of minimum unstick) is planned for mid-month. This highly intense maneuver is used to determine what the lowest speed is at which the aircraft can still take off.