Airbus is working hard to complete A350 flight testing, which it hopes to close by the end of next month in preparation for formal European Aviation Safety Agency airworthiness approval in September. Principal remaining work involves long-range flights now under way following a maximum-energy rejected takeoff (MERTO) demonstration at Istres Air Force Base in France on July 19. By July 22, the five A350 test aircraft had logged more than 2,250 hours during about 540 flights involving more than 1,380 takeoff/landing cycles.
Airbus is conducting the route-proving campaign with A350-900 MSN 005, which by early July had accumulated almost 36 flight hours in its first six flights since taking to the air on June 20. One of two A350 flight-test aircraft equipped with an airline cabin interior and sporting only a “light” flight-test equipment fit, MSN 005 also performs operability checks, crew training and extended twin-engine operations.
According to flight and integration tests senior vice president Fernando Alonso, route proving has proved “quite a logistics exercise” that will require several flight crews positioned around the world. The aircraft will undertake 26 flights totaling some 200 hours’ flying representative of airline operations, including high-airfield performance, auto-landing trials, and airport turnaround and handling services. Plans called for MSN 005 to visit Australia, Brazil, Canada, Chile, Finland, Germany, New Zealand, Qatar, Russia, and South Africa, with the campaign including a shuttle of four Hong Kong-Singapore round trips separated by 90-minute turnarounds.
Although Alonso acknowledges that A350 test flights have involved operating at “way over” normal maximum takeoff and landing weights, the MERTO demonstration with MSN 001 used more representative values, or around 275 metric tons at 160- to 170 knots. Typically, such tests require an aircraft to come to a halt from maximum V1 speed at maximum takeoff weight using 90-percent worn wheel brakes, no reverse thrust and with no damage to the aircraft from any landing gear fires that might break out within five minutes.
An earlier high-energy rejected takeoff (not necessarily at maximum weight) had cleared the A350 for initial long-flight demonstrations. “[MERTO] involves a combination of weight and speed,” said Alonso. “We set the [demonstration] speed finally just before brake release [when we know] the actual aircraft weight.”
Airbus expects to retain A350s MSNs 001 and 002 and to refurbish the remaining three test airframes for customers. Post-certification work includes aircraft configuration testing for launch customer Qatar Airways, which should receive the aircraft “towards the end of the year.”