Airbus completed the opening of the A380’s flight envelope at the beginning of December, with the successful demonstration of its maximum design speed (Vmd/Mmd). However, recent water ingestion trials had to be aborted because of the need for modifications and the test will be re-run next year.
Completion of the flutter tests in November and the Vmd/Mmd test to Mach 0.96 on 1 December signalled the end of the flight envelope expansion, says Airbus senior vice-president flight test Claude Lelaie. He adds that an Vmd/Mmd attempt earlier in the flight test programme had to be aborted at M0.93 “when we detected a shockwave, but this was rectified by calibration and we have now reflown the test to Mach 0.96”.
Lelaie says the A380 was dived from about 39,000ft (11,900m) and “reached M0.96 quite easily with a small rate of descent compared to other aircraft – the pitch down attitude was only 7° – which shows that its drag is low”.
Lelaie says the next major task for the flight test team is to fine-tune the fly-by-wire flight control rotation law.
Airbus recently ran a series of water ingestion trials at the Istres test centre, which involved accelerating and decelerating the A380 to 70kt through a water trough. “We had to abort the test as some hydraulic pipes to the brakes were bent,” says vice-president flight test Fernando Alonso. “We are modifying the pipes and will then re-run the test.”
MAX KINGSLEY-JONES/TOULOUSE
Source: Flight International
