David Lee, Golda Nguyen and Scott Gleason recover the Prandtl-D No. 3 after one of its first flights.

The Prandtl-D No. 3 research aircraft is being readied for new flight tests this summer. It had its first flight on Oct. 28, 2015.

The streamers on the Prandtl-D No. 2 as it is launched illustrate how aerodynamic forces are maximized as birds overlap wingtips when flying in formation.