i started to wonder more about contrails after this weekend when i went spotting up at CLE. it was a perfectly clear early evening and using my binocluars i was able to watch quite a bit of traffic up at altitude.most of the traffic that caught my eye was because of its contrails, but there were a few (i'm sure MORE that i DIDN'T see) that had no contrails. i was able to spot them only because they were positioned perfectly so the sun shown off their fuselages. 2 were Lufthansa A340's heading SW-NE and could be seen clear as day with binoculars. one called CLE center as LH441 KIAH-EDDF at FL330. these 2 A340's had no contrails.so....why do some enroute aircraft have contrails, while others don't?thanks!chris

"why do some enroute aircraft have contrails, while others don't?"The difference is mostly air temperature. Take a look at this:http://cimss.ssec.wisc.edu/wxwise/class/contrail.htmlThis reminded of something funny I saw on TV. It was, I think, an MSNBC reporter who pointed to the sky and said he could see B-52's on their way to Baghdad. Then he paused and said, "actually I can't see the aircraft, only thier entrails"oops!

excellent!thanks for the link!chris

actually the site posted above is part of a massive govermental cover up of huge proportions.If you want the real truth, you must go here:http://www.netowne.com/environmental/contr...tings/part2.htmAt times like this we must all be very very carefulp.s. ;-)

Those are Chemtrials not contrails. All planes are fitted with special fittings to spray these chemichals in the air intended to brainwash people and keep them under control. LMAO..at least that's what this woman thinks.:http://www.anomalies-unlimited.com/I love that site, when I need a good laugh I visit and take a look at their ChemTrails section.Mike