This is an excerpt from the 1944 film “The Memphis Belle: A Story of a Flying Fortress”. The full original film is public domain, and can be found here:

http://www.archive.org/details/TheMem…

The film shows contrail formation, including showing “broken” contrails.

http://www.youtube.com/watch?v=wfOrez6q7WM

Make sure you listent to the audio, as it explains how high the planes are, how cold it is, and why contrails form.