A pilot flying an F35 stealth fighter jet put the plane on auto-pilot and then ejected. The U.S. military is still looking for it:

https://www.msn.com/en-us/news/us/have-you-seen-a-missing-stealth-fighter-jet-us-asks-public-for-help-after-mishap/ar-AA1gSlUI

https://nationalpost.com/news/world/us-military-help-finding-fighter-jet