When using the Jetstream does a pilot aim towards it deliberately(If within a short journey time of it) to gain time ( and save fuel) And has to veer off when near the destination (going west to east)
And when going east to west is it a Fixed direct route at a lower altitude?

This message has been edited. Last edited by: bedstor,

The jetstream typically is a rather narrow 200 mile (or so) wide strip at around 30,000 to 40,000 feet with average winds at 100 mph (sometimes much more); a pilot (commercial/military jet aircraft) will use it to his/her advantage if it happens to set up close to the intended flight path. Such use is determined prior to departure and cordinated with air traffic control. The jetstream is not always positioned in a location or moving in a direction that can shorten flight time, although generally the west to east flights are faster because that is the prevailing wind direction even outside of or below the jetstream width and elevation, but at a lower wind speed. Across the Atlantic in the winter, the jetstream does sometimes flow in a direction common to the 'great circle' (shortest distance)route from NY to London, in a generally SW -NE direction, and this greatly dcreases flight time from Ny-London, but increases it going the other way. A pilot will not necessarily be able to avoid the jetstream headwinds, since to do so would require a large deviation in path resulting in no gain, plus other factors from air traffic control come into play that would limit such deviation. Altitudes are pretty much fixed at 30 to 40,000 feet across the Atlantic, so lower altitudes are not used to avoid the jet (they'd have to be real low anyway (below 20,000 feet)for any substantial gain.

Thanks Gerry that adds nicely to what I saw in a TV Documentary the other day
Was surprised to learn it was accidently discovered by American pilots just before the end of WW2 when flying the first pressurised Bombers at high altitude and the navigators kept losing their bearings

quote:

Discovery
The jet streams were first discovered by the Japanese meteorologist Wasaburo Ooishi in the 1920s by the tracking of weather balloons. His published work went largely unnoticed outside of Japan as he chose to write in the international language of Esperanto which was little read in scientific circles. However, it was utilised during World War II by the Japanese military in the fire balloon attacks on the American mainland (see below).

During World War II the American aviator Wiley Post and military pilots flying Boeing B-29 Superfortress bombers at high altitudes found the winds made precision bombing at those heights almost impossible. The theory of the jet streams was explained by Erik Palmén and other members of the Chicago school of dynamical meteorologists. The first practical use of jet streams was the Japanese fire balloon attacks on the American mainland later during the World War II.