Why do jets leave a white trail behind them.

"AliR" wrote in message
. ..
Oh it's called Contrails, I didn't know that. I found lot's of info on it
on the web. Thanks.

Which is short for "condensation trails."

The water produced from burning lots of gallons of Jet A fuel, producing
water, in vapor form, (lots of it) then exhausting it into very cold air
(20, 30, 40 degrees F, below zero) causes nearly all of that moisture
condense into visible water vapor, pretty quickly.

If you notice, sometimes, you see a space behind the jet where there is no
visible vapor, then it finally cools enough to become visible.

This same thing even happens behind piston engines. They are still burning
fuel, producing water, and having it cool greatly. It is most often seen
behind the high level, heavy bombers of WWII.

I remember the Jimmy Stewart flick, where he was called back into service
after WWII, in the Strategic Air Command. I think that was the name of the
movie, also. Anyway, if you don't get anything else out of the movie, the
flying scenes are "to die for." There are many minutes of seeing the B-36's
flying at very high altitude, with the contrails appearing a few hundred
yards behind the planes.

Kinda neat.

Of course, these planes had jet engines, and gasoline engines, and a lot of
them. Aluminum airplanes, and iron men! Make a point of seeing that movie.
It is worth it.

Extra points, for trivia. What kind/s of fuel did the B-36 carry?
--
Jim in NC