Reduce the Fuel Burn

Pilots should not but the system controller of a well designed network could.

pilots are to get on the assigned 'freeway', follow it and report to air control if they have problems at which time they could request a new route assignment.

The air control system should take all this into account but as the technology they use is rather ancient ---

I don't think its so much about favourable winds, although that could help. As a general rule, the higher you fly, the less dense the air, the lower the drag, the less thrust you need to keep going, the less fuel you need to burn. The ideal flight profile is to fly as high as you can, and, as the aircraft lightens as fuel is consumed, adopt a gentle 'climbing cruise' profile for most of the flight. This is what I believe Concorde used to be able to do, because if flew well above the normal flight levels.

Its an air traffic control restriction to keep aircraft at fixed flight levels, even in those jurisdictions where they respond to pilots requesting higher flight levels mid flight

Don't they already use the jet stream?

This isn't a GPS issue so much as an air traffic control issue. Depending on the jurisdiction, the direction of flight often dictates altitude choices. At least under IFR rules, which most commercial traffic follows.

For example (and these are not from any real rules, just an extrapolation of many around the world), flying west might dictate flying at an odd Flight Level (33,000) while flying east might dictate an even level (32,000). Flying northeast may dictate an even flight level +500' (32,500).

A pilot under traffic control is almost always free to request a change to another flight level that may be more advantageous to his arrival time and fuel consumption.

A pilot not under traffic control has a bit more latitude but is still most likely to follow these conventions.

The real question is: should we allow pilots more freedom of choice in their routes outside of established airways. I would vote not. It's already plenty crowded up there.

Hooker

Agreed! That is why I pointed out that an advanced air control system might be of use but it should not be left to the pilots.

They have other things to think about - like schedules on their laptops!

ROFL.

Touche!!

yes as long as flight safety time factors are not compromised on

İndividual pilots all working out their own constantly changing flight plans?

No thank you!

Its a simple question that bears a simple answer...."Yes" followed by: a plan/system.