[DOC] [TLE] Contrail - Wikipedia [PAR] Contrails or vapor trails are line-shaped clouds sometimes produced by aircraft 
engine exhaust ... "Vapor trail" redirects here. ... The main products of 
hydrocarbon fuel combustion are carbon dioxide and water vapor. At high ... 
Contrails produced from jet engine exhaust are seen at high altitude, directly 
behind each engine. [DOC] [TLE] Jet engine - Wikipedia [PAR] A jet engine is a reaction engine discharging a fast-moving jet that generates 
thrust by jet ... These engines offer high speed and greater fuel efficiency than 
piston and .... Meanwhile, in Britain the Gloster E28/39 had its maiden flight on 15 
May 1941 ... The legacy of the axial-flow engine is seen in the fact that practically 
all jet... [DOC] [TLE] 1EPA Aircraft Contrails Factsheet - Federal Aviation Administration [PAR] are visible behind jet aircraft engines, typically at cruise altitudes in the upper ... 
Contrails have been a normal effect of jet aviation since its earliest days. ... If 
sufficient humidity occurs in the exhaust plume, water con- ... a by-product of 
combustion. ... contrail shown here was formed at a lower altitude where higher 
humidity. [DOC] [TLE] How Much Water is there in Jet Engine Exhaust? [About 1.3 Gallons ... [PAR] Jul 25, 2014 ... Engine Efficiency, High Bypass, and Contrail Frequency - How much? .... It's quite 
surprising, the amount of water in jet exhaust. ... Secondly, aren't the by-products 
formed in the engine as it exhaust, so how could .... that when combustion occurs, 
YOU (and I and others) breathe in, right here at ground level. [DOC] [TLE] Why do jet engines get better fuel efficiency at high altitudes? [PAR] Feb 7, 2014 ... But that probably just shows how little I know about jet engines. ... Concorde was 
super-efficient at its cruise altitudes when flying at Mach 2.00+. .... complete, the 
maximum temperature given here will not be reached in reality. ..... ceiling of 
Boeing and Airbus products remained about the same for 30 years? [DOC] [TLE] Contrail Science  The Science and Pseudoscience of Contrails and ... [PAR] This type of contrail is seen in high local humidity, as indicated here by the misty 
.... Ice will only sublime if the humidity (at that altitude) is lower than around 60% 
to 70%. .... When jet exhaust comes out of the engine, it's superheated. .... Often 
this comes from soot and sulphur and other byproducts in the engine exhaust. [DOC] [TLE] Why do some planes leave long trails, but others don't?  Contrail ... [PAR] Mar 5, 2010 ... This can occasionally be seen with high altitude refueling, when the plane ..... 
The point here is that different engines produce different contrails. ..... 2) Jet 
engines are bigger and more efficient, producing more and larger contrails .... Is 
there any evidence that it it is occurring, or do you just think it's the type... [DOC] [TLE] NASA Goes Down Under to Tap High-Altitude Ice | NASA [PAR] Feb 26, 2014 ... A French jet is part of an Australian flight test to better understand ... "We have 
tested a full scale engine under high altitude ice crystal icing conditions in that 
lab. ... "If those crystals are ingested into a turbofan engine and reach its core ...... 
version of aerogel, similar to what is seen here, as a foundation for a... [DOC] [TLE] High-Altitude Ice Crystal Icing | BCA content from Aviation Week [PAR] Feb 2, 2015 ... High-Altitude Ice Crystal Icing Can Cause Engine Failure. ... No, stay hereYes, go 
to AWIN ... This type of icing does not appear on radar due to its low reflectivity. ... 
the core of jet-based engines have been occurring for over two decades. .... 
seen in high-level cirrus, cirrostratus and cirrocumulus clouds. [DOC] [TLE] Patent US4302933 - Jet engine augmentor operation at high ... [PAR] Dec 1, 1981 ... In the operation of an air atomized jet engine augmentor oil burner, ... The 
procedure here is to measure the density (pressure) of the

Question: Occuring at high altitudes, it's the jet engine by-product seen here
Answer: vapor trail