There are several trajectories of interest for the analysis of horizontal flight efficiency.
Filed Tactical Flight Model, corresponding to the last filed flight plan (see also FTFM)
Current Tactical Flight Model (see CTFM)
Correlated Positions reports for a Flight, i.e., airspace profiles following as much as possible the actual flown trajectory (based on radar positions - see CPR).
Profiles generated by the CFMU path generation tool.
Shortest Constrained Route. IFPS compliant route (available CDRs open and RAD compliant).
Shortest RAD restrictions applied Route. All CDRs open.
Shortest Unconstrained Route. No RAD applied, all CDRs open.
Direct route. Any portion outside the FPM_AREA is “frozen”, i.e, not generated by the tool.
The comparison between values for different trajectories of the same flight provides indication on the effects of different factors:
- SUR vs DCT provides a measure of the effects of route design, because it compares the shortest theoretical course with the best one available using the route network.
- SUR vs SCR provides a measure of the effects of route availability, because it compares the route potentially available on the route network with the one that could actually be filed.
- FTFM vs SCR provides a measure of the route utilisation by Aircraft Operators, because it compares the route actually filed to the best that could have been filed.
- CPF vs FTFM provides a measure of the effects of ATC because it compares the actual trajectory to the one that was filed.