Aluminium alloy leading edge to be supplanted by Glare in move to cut fin's weight

Airbus has revealed more details of its plans to replace the traditional aluminium alloy leading-edge - or "D-nose" - of the vertical and horizontal stabilisers of the A380 with Glare, the glassfibre-reinforced aluminium composite material that is also being used for much of the upper fuselage skins.

The weight-saving measure is expected to cut 20% off the overall weight of the 14m (46ft)-tall fin, and a similar amount from the tailplane, says Jens Hinrichsen, director A380 vertical tail and component management and integration team at Airbus Deutschland. Although Airbus declines to specify the actual weight of the current fin, it is widely estimated to come in at around 3t. Revealing the initiative at the handover of the first operational shipset of carbonfibre-reinforced plastic vertical-tail truss structures by Los Angeles-based Hitco Carbon Composites, Hinrichsen says the first aircraft in the build sequence to take advantage of the lighter material will be serial number 007, the fourth flying airframe to be built and the "light-duty" test aircraft aimed at route proving, endurance and operational tests.

The move to Glare was first considered as early as 2002, but the urgent search for weight-saving measures has pushed the development to a virtually all-composite empennage. After completion of the test programme Airbus will retrofit 002 and 004, the second and third flight-test airframes, for onward sale. The final decision to go to a Glare D-nose was taken after a successful set of birdstrike tests in December 2002 and July 2003 (Flight International, 14-20 October 2003). "Glare has a very high damage tolerance property, but we didn't know for sure if it was OK for large deformations until we completed the 8lb [3.6kg] bird strike test." However, the time taken up by subsequent contract and design changes means that the first application cannot be until 007, adds Hinrichsen.

Airbus Deutschland has meanwhile "closed" the vertical tail structure of the static test aircraft, dubbed "ES" (engineering, static), and has begun assembly of the first flyable tail for 001 - the prototype. Assembly of the fin for 002 starts by the end of January, while assembly of the unit for the fatigue test airframe "EF" (engineering, fatigue) starts in March.

The Stade-built fin torsion box consists of 16 ribs, the largest and lowest seven of which are being made by Hitco. Up to 12 fins are planned for production in the first year, with a maximum planned production rate of up to 40 a year.

Messier-Dowty has delivered the first test A380 nose landing gear to Airbus UK. The gear, 4.8m tall when fully extended, will be fitted to the Airbus system test rig at Filton, UK. Goodrich is producing the A380's main landing gear.

Source: Flight International