Why do jets leave a white trail behind them.

Purple 115/145 avgas, burns just fine in the jet and was
required by the big P&W radials.


"Jay Beckman" wrote in message
news:EcUzf.9831$jR.3049@fed1read01...
| "Morgans" wrote in message
| ...
|
| "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
|
|
|
| Since it had "six turnin' and four burnin'" did it have to
carry AvGas and
| JP?
|
| It also carried a nuclear reactor aloft at one point:
|
| http://www.cowtown.net/proweb/nb36h_jde.htm
|
| Jay B
|
|