Airbus is opting to switch back to nickel-cadmium batteries for its A350 as a risk-reduction strategy, but insists the change will not affect entry into service dates.

It will continue to equip its flight-test aircraft with lithium-ion batteries in order to preserve the schedule for maiden flight and initial envelope testing.

Flight-envelope tests are independent of the source of electrical power and Airbus is still aiming to have the first flight-test aircraft, MSN1, airborne in mid-year.

But Airbus will pursue a certification programme with nickel-cadmium batteries for production aircraft, the first of which are due to be delivered in the second half of 2014.

It will retain battery supplier Saft for the new scheme. Saft had been selected to supply lithium-ion batteries to the A350. Airbus is likely to use a version of batteries designed for the A380.

Airbus is changing the battery strategy in the wake of the still-unexplained incidents involving lithium-ion batteries on the Boeing 787, which resulted in the 787 fleet being grounded in mid-January.

While Airbus says it is "confident" that the lithium-ion battery architecture is "robust and safe", it says the root cause of the two incidents occurring on Japanese 787s remains "unexplained, to the best of our knowledge".

It says it is opting to ensure the "highest level of programme certainty" and will revert to "proven and mastered" nickel-cadmium technology as the "most appropriate" strategy.

Airbus has yet to detail any specific electrical architecture changes which might be required as a result of the switch, but says it is taking the decision early in order to preserve the flight-test and entry-into-service schedule.

It had already indicated that it was looking at alternative sources of power for the A350, following the 787 incidents. But the airframer had pointed out that the A350 - which has a more conventional electrical system - does not need the same battery-driven power levels as the 787.

Airbus also says its A350 has "unique" power, insulation and venting features in its main battery design.

"Special attention was given to mitigate the identified risks inherent to this technology," it says, adding that it will embark on "additional maturity studies" focusing on lithium-ion battery behaviour.

Source: Air Transport Intelligence news