On Sat, 11 Dec 2004 20:42:05 +0000, Michael Calwell
wrote in
::

I work outdoors beneath the flightpath to Edinburgh Airport.

I take it that vapour trails are the condensed water contained in the
air ingested by the engines. My question is, how much air does an engine
ingest at cruise? How would you visualise that amount of air?

If I recall correctly, as a result of the ban on flight over the US
following the 9/11 terrorist attack, there was a measurable
temperature rise attributed to the reduction in airliner contrails.

Yahoo yielded this:
http://p211.ezboard.com/fchemtrailss...picID=75.topic