Flight Plans and Routing

[surlybondfree]

Hi,

How do you get the optimum route with the shortest distance when filing a flight plan? From eurocontrol/CFMU documents, it appears that operators receive a prompt to refile when a better routing option becomes available - is this effective at reducing the planned distance, or is it more usual to get short cuts en route from ATC after the plan is filed?

Thanks!

[5milesbaby]

Shortest distance isn't always the optimum route

[surlybondfree]

Yes, fair point, and without knowing the operator's cost index, I guess the CFMU can only suggest better routings in non-marginal cases.

But presumably the operator knows quite accurately how far off optimum a route is from the trip cost calculated by the flight planning software, and comparison with previous history on that sector?

I seem to remember reading in a CFMU handbook the suggestion to try refiling for a different cruise altitude if the initial route is too long. So my question was really is this refiling process to improve the routing really effective, or can/do pilots rely on getting shortcuts from overly long/costly planned routes when in the air?

[5milesbaby]

I cannot comment on the bulk of what you ask, I'm sure Flowman et al will be along soon, however from the radar perspective, I wouldn't expect on getting anything better once airborne. Some ATC providers are instructing their controllers to adhere to the flightplan religiously, especially where a difference of requested and filed levels occurs. HOWEVER, there are certain routes I know of in the UK that only become available after certain times due to danger area activity. Should notification come that the activity has ceased early then the sector responsible for the route would normally offer the now available shorter route.