30 October 2013

MSN5 flight-test prototype will be the first A350 with Ni-cadmium batteries.

Last Feb/2013, Airbus announced that they were switching back to nickel-cadmium batteries for the A350 XWB as a risk-reduction strategy, but insisted the change will not affect EIS-entry into service dates.

Initial flight tests are being performed with lithium-ion batteries, because it was already too late in February to implement the change for the early part of the flight test program. However, the A350 will later be certified with Nickel-Cadmium batteries.

MSN1,MSN3, MSN2 and MSN4 flight-test aircraft are being equipped with lithium-ion batteries but the last flight-prototype, MSN5 will be equipped with nickel-cadmium batteries, used to complete the certification program needed for series aircraft, the first of which is due to be delivered to Qatar in the second half of 2014.

It was planned to equip with nickel-cadmium batteries the first 3 batches until MSN20 but it could be that the Ni-Cad batteries will be installed from MSN6, based on the news in La Tribune.

The series aircraft where the Ni-Cad batteries manufactured by Saft are installed will require specific electrical architecture changes.

Reverting to less volatile Nickel-Cadmium would mean sacrificing improvements in weight in the lighter Lithium-Ion batteries, equivalent to one adult male passenger out of between 270 and 350 passengers and cargo on board.

“The penalty in weight compared with the risks associated with Li-Ion is minimal,” said Nick Cunningham, an aerospace analyst at Agency Partners in London.

Airbus – like Boeing – is using lithium-ion batteries because they are smaller and lighter than equivalent devices based on nickel cadmium. Bombardier is using Nickel-Cadmium batteries for the Cseries.

“We confirm we are opting for nickel cadmium for the A350 main batteries to protect the programme schedule. This decision is about protecting the integrity of our program schedule… it’s not about any safety concerns about Li-ion batteries, we continue in parallel to mature for the A350. With so much uncertainty raised by the Boeing 787 investigation, we are being prudent in order protect our programme schedule. This is business as usual.”

Airbus said the concerns did not necessarily center around the technology as such, but were caused mainly by the regulatory uncertainty following the 2 Boeing 787 incidents. Airbus was worried about late additional compliance criteria that could have been introduced by the European Aviation Safety Agency (EASA). The company plans to mature the technology further nonetheless.

“We didn’t seek initial certification for the A350 with lithium because we didn’t want to take any risk of delay,” Evrard said in Toulouse. “But we think our lithium power design is sufficiently different” from its rival’s system, he said.

Based on the article “Premier vol sans problème pour le deuxième A350 d'essai d'Airbus” published in La Tribune

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