Hispano-Suiza on board the A350 XWB

The Trent XWB-84 engine (Rolls-Royce) set to fit out the new Airbus A350 XWB, passed certification on February 7, 2013. Hispano-Suiza (Safran) has been chosen to supply the engine's entire power transmission system. Yannick Bonnaire, Hispano-Suiza's Vice President for Programs, brings us up to speed.

What does this contract represent for Hispano-Suiza? What exactly does it involve?

The new contract is just the next step forward in our almost 30-year relationship with Rolls-Royce. When Hispano-Suiza and Rolls-Royce signed the agreement in 2008, we became the exclusive supplier for every version of the Airbus A350 XWB's power transmission system. And with over 600 firm orders for Airbus's future medium-haul aircraft already in the pipeline, it's a really important contract for Hispano-Suiza, especially since Rolls-Royce is the only engine manufacturer on board at the moment! Another important aspect is that the contract covers the entire life cycle, and includes both the initial supplies and maintaining them during operations. That's why our equipment has to be reliable.

What sets the program apart?

For the very first time, our client entrusted us with the engine's entire power transmission system. That means Hispano-Suiza will be supplying the full chain, made up of six major components*, from the high-pressure and radial driveshaft bevel gears (which recover the power needed on the shaft) right down to the accessory gearbox, including the gears. Our system can develop 800 kW of power, and is fully in line to meet the performance requirements of next-generation engines.
Its behavior has already been validated in all flight phases on the test bench at Hispano-Suiza's production site in Colombes. But ramping up production to two or three times what we were used to on our last programs is going to be a major challenge.

What disruptive technologies and changes can we expect to see soon in the field of power transmission?

Hispano-Suiza is currently working on groundbreaking new architecture that will optimize the position of the power transmission system on the engine. It's something we are working on very closely with Snecma (Safran) at a really early stage. The Group's Materials and Processes Department has also been helping with studies to simplify the way we make critical parts like gears and shafts and reduce their weight at the same time. In the shorter term, we're working on carving casings right out of a block of aluminum so we can wean ourselves off the foundry. That'll bring down manufacturing costs and open up new sources of supplies.
And a final thing we're working on at Hispano-Suiza is integrating the electric generator into the power transmission. Bringing the power transmission's electric and high-precision mechanical sides together will showcase our whole gamut of expertise.

(*) See box

High-tech power transmission

The power transmission system was specially designed to guarantee optimal performance in the future Airbus A350XWB's engine, the Trent XWB-84. It will include the very latest in manufacturing-process and supply-chain-management innovation.
It is divided into six main components: the AGB (Accessory Gear Box), the TGB (Transfer Gear Box), the angle driveshaft, the IGB bevel gears (Internal Gear Box), the SAGB (Step Aside Gear Box), and the oil tank, supplied by the Techspace Aero (Safran) subsidiary, ACI.