Jet route
A route designated to serve flight operations from 18,000 feet MSL up to and including FL 450.
Jet stream
A high-velocity narrow stream of winds, usually
found near the upper limit of the troposphere, which flows
generally from west to east.
Judgement
The mental process of recognizing and analyzing
all pertinent information in a particular situation, a rational
evaluation of alternative actions in response to it, and a timely
decision on which action to take.