The FAA has given Boeing the go-ahead for test flights of two aircraft with a redesigned battery system for the Boeing 787 Dreamliner.

This isn’t an all-clear to get the Dreamliner back in the air for its awaiting commercial aviation customers, but instead it gives Boeing the opportunity to demonstrate that its fix complies with FAA safety regulations.

The FAA says Boeing has redesigned the internal components of the battery to minimize the possibility that a short-circuit will be initiated; created better insulation of the battery cells, and has added a new containment and venting system.

“We won’t allow the plane to return to service unless we’re satisfied that the new design ensures the safety of the aircraft and its passengers,” said Transportation secretary Ray LaHood.