Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Four representative cases demonstrating the variation of forces experienced by spread (circle) and non-spread (triangle) tails during a wingbeat cycle. Spread angle Φ pertaining to the maximum force computed for the spread tail is noted. Zones shaded grey correspond to the period of a downstroke.
