[CFIIIMEIATP737]

Jets do not always make contrails. Contrails are based on the temperature of the air and the amount of moisture in the air.

In your post, the contrail stops. That could be caused by the pilot needing to initiate a descent and closing the throttles to idle.

And piston aircraft can make contrails, too.

[ProtectOurFreedom]

More likely atmospheric conditions changed. If you don’t have the right pressure, temperature, and humidity, the contrails don’t form. They can turn on and off quickly.

Or you can have CGI do it for you.

[Tijeras_Slim]

The excellent and highly detailed youtube channel WWII US Bombers did a recent video on the types of contrails produced by bombers (3 kinds) and the conditions under which they were produced. The guy has apparently limitless access to Air Force archives.

[roving]

Whistleblowers have come out and said what those chemtrails are.

[Pelham]

The 8th Air Force must have been the original "chemtrailers". "Chemtrails" do have a purpose, they serve as an ad hoc test to see if someone knows as much about physics and chemistry as a well read 5th grader.

[Jane Long]

You sound like my hubby....every time I point out the chemtrails! :-)