Air India has six Dreamliners and has ordered 21 more. The question of the airline seeking compensation from Boeing for the jet’s glitches would be taken up once the aircraft are flying again, Nandan said.

“We have been in close communication with our customers since this issue arose,” a Boeing spokesman in Seattle said, regarding the issue of compensation. “The details of our conversations with customers are confidential.”

The Boeing spokesman declined to address the details of the battery fix, but said it was making progress.

“Boeing has teams of hundreds of engineering and technical experts who are working around the clock with the sole focus of resolving the issue and returning the 787 fleet to flight status,” he said. “Everyone is working to get to the answer as quickly as possible and good progress is being made.”

On February 7, in its most recent official update on the Dreamliner, the NTSB said it had a “long road ahead” in its investigation of the lithium ion batteries.

Spokesmen for Japan’s All Nippon Airways Co Ltd (ANA) (9202.T), which has the biggest fleet of Dreamliners, and Japan Airlines Co Ltd (JAL) (9201.T) said they were unaware of the suggested April schedule.

ANA and JAL have been most affected because they own around half of the lightweight, fuel-efficient jetliners in operation as a strategic move to win market share from their U.S. and European rivals.

Boeing shares rose on 1.3 percent on Wednesday, to $75.64 on the New York Stock Exchange.

(Reporting by Anurag Kotoky; additional reporting by Bill Rigby in Seattle, Yoko Kubota and Mari Saito in Tokyo, Andrea Shalal-Esa in Washington and Devidutta Tripathy in New Delhi; Editing by Daniel Magnowski, Jim Marshall and Carol Bishopric)