Basically it introduces time, the fourth dimension, into the management of flight trajectories. This results in a very accurate and predictable trajectory of aircraft, compared to current systems, that can be shared with control centres ensuring optimal and safer flight operations.

Question No. 1247 Ms. Olivia Chow: With regard to changes made or planned to be made by NAV Canada to flight paths of aircraft arriving at and departing from federally-owned airports in 2012 and 2013 year to date: (a) which airports are affected by the flight path changes; (b) how many flights and what percentage of total flights are subject to flight path changes, broken down by i) incoming and outgoing flights, ii) flight arrival or departure time, iii) affected airport; (c) what is the justification for the changes; and (d) have consultations taken place on these changes and, if yes, what are the (i) groups consulted, including, bu ...[+++]t not limited to, public consultations, (ii) date of the consultations?

the average horizontal en route flight efficiency indicator is the difference between the length of the en route part of the actual trajectory and the optimum trajectory which, in average, is the great circle,

‘flight intention’ means the flight path and associated flight data describing the planned trajectory of a flight to its destination, as updated at any moment.

‘flight path’ means the path of an aircraft through the air, defined in three dimensions.

establish criteria and procedures providing for the creation and the use of adjustable lateral and vertical limits of the airspace required for accommodating diverse variations of flight paths and short-term changes of flights.