The second phase includes both ground and flight tests. Electric motors, batteries, and instrumentation are some of the technologies being tested in this section. A new wing design to accommodate two new engines has also been developed, but is not yet flown on the X-57 at this stage.
The new wing design to reposition motors is a part of the third phase. This phase, which overlaps with Modification 2 and 4, also includes building and testing additional components for the final version of the X-57.