Jahthunda From , joined Dec 1969, posts, RR: Posted (13 years 7 months 3 weeks 3 days 1 hour ago) and read 2195 times:
Hello to everyone, i'd like to know is it exhaust fumes coming from the aircraft engines while flying at high altitudes or is it vapor trails?, I always notice it happens to 4 engines aircrafts and, I've seen two engine aircraft flying very high and there is no smoke or vapor.
Jsbothe From , joined Dec 1969, posts, RR:
Reply 1, posted (13 years 7 months 3 weeks 2 days 22 hours ago) and read 2160 times:
i think it's trails in which the atmospheric humidity condenses around smoke particles, so it's both, although it's more water than exhaust fumes. it only happens when the humidity is high enough, so that the air cannot keep all the steam in gasious form.
it happens to all forms of aircraft, as for as i know, even to propeller-driven aircraft. it only depends on the humidity in this area.
hope this helps
F-WWAI From Andorra, joined Dec 1999, 131 posts, RR: 0
Reply 2, posted (13 years 7 months 3 weeks 1 day 18 hours ago) and read 2124 times:
note: water in gaseous form is absolutely transparent!
water steam is tiny little droplets kept in suspension.
aircraft fuel is CnHn+2, a hydrocarbone. If fuel is burned, it produces, essentially, H2O water in gaseous form and the CO2 everybody is talking about.
if it's cold and not extremely dry in the atmosphere, the gaseous water condensates forming the steam you see. It's swirled by the aircraft vortexes. The steam eventually either dissipates amongst the clouds or dries away ..
Tarantine From United States of America, joined Sep 2000, 210 posts, RR: 0
Reply 3, posted (13 years 7 months 3 weeks 1 day 13 hours ago) and read 2101 times:
The trails are not smoke. It is water vapour or ice. The number of jet engines makes no difference at all. I think the word "Contrails" is the correct term for the trails, but I have no idea who thought of that word (maybe people at Convair).
SHB From , joined Dec 1969, posts, RR:
Reply 6, posted (13 years 7 months 3 weeks 19 hours ago) and read 2079 times:
F-WWAI is right. Water is a byproduct of combustion. At the low
temperatures at high altitude aircraft engines produce a vapor
trail. The same reason you can see your breath in cold weather
or a car's exhaust produces steam and drips water in the winter.