The demonstrator aircraft, dubbed ‘Flight Lab,’ took its first flight on 26 September, taking off from the Tarbes aerodrome in southern France and after a series of tests landing at Airbus’ facilities in Toulouse Blagnac. The overall flight time was 3 hrs 38 mins.
The BLADE (Breakthrough Laminar Aircraft Demonstrator in Europe) project is tasked with assessing the feasibility of introducing the technology for commercial aviation. It aims to improve aviation’s ecological footprint, bringing with it a 50% reduction of wing friction and up to 5% lower CO2 emissions. Airbus says the A340 Flight Lab is the first test aircraft in the world to combine a transonic laminar wing profile with a true internal primary structure.
On the outside the aircraft is fitted with two representative transonic laminar outer wings, while inside the cabin a highly complex specialist flight-test-instrumentation (FTI) station has been installed.
One of the new wings is made of an integrated upper cover and leading edge in carbon fibre reinforced plastic (CFRP) (SAAB concept on the port wing) and the other one is made of a separate upper cover in CFRP and a metallic leading edge (GKN concept on starboard wing). The project intends to test natural laminarity sustainability in real operational conditions, in order to be able to properly specify and design (by specifying manufacturing tolerance requirements) future laminar components/wing for a next generation commercial aircraft.
The extensive modifications to the A340-300 test-bed aircraft took place during the course of a 16-month working party in Tarbes, with the support of industrial partners across Europe. The first flight marks the kick-off of the Blade flight test campaign to explore the wing’s characteristics in flight.
In the run-up to the start of this flight testing phase, a small team of 10 specially trained pilots, test engineers and flight test engineers had prepared for this milestone for several months, spending time in a simulator and familiarising themselves with the FTI systems to be installed on the Airbus flight-test aircraft. On equipment installation side, a working party of 70 people performed the FTI installation inside the aircraft, while teams from Bremen, Germany, and Broughton, UK, worked externally on the outer wings, with a team from Stade, Germany, installing a pod containing infrared cameras on the fin.
On the wings, there are hundreds of points to measure the waviness of the surface to help Airbus engineers ascertain its influence on the laminarity – which is the first time that Airbus has used such a testing method on an aircraft. Other ‘firsts’ are the use of infrared cameras inside the pod to measure wing temperature and the acoustic generator which measures the influence of acoustics on laminarity. In addition, there is an innovative reflectometry system which measures overall deformation in real-time during flight.
A key goal of Blade is to be able to measure the tolerances and imperfections which can be present and still sustain laminarity. To this end, Airbus will simulate every type of imperfection in a controlled manner, so that at the end of the campaign the tolerances for building a laminar wing will be fully known. The Flight Lab will perform around 150 flight hours in the coming months.