STEP ALTS: PLAN THE CHANGE, THEN COMMAND IT
STEP ALTS allows a planned cruise-level change to be studied in the route's time/fuel predictions. The supplied 2004 standard permits one planned step and applies explicit position/phase conditions. Fenix V3 documents work on step computations and S/C/S/D pseudo-waypoints, but that does not establish that every capacity, optimization or boundary condition is identical to the old guide. Read the actual page and supported result. [66, PDF pp. 420-423,191] [82]
1. Choose a planning case. Identify the intended level and step point from the actual plan, keeping clearance separate. EDDF-EGLL at FL280 need not have a useful step at all; a short sector is not improved by adding one simply to fill this chapter. Use a suitable separate study route or a justified actual case when examining the feature in depth. [66, PDF pp. 420-423,191]
2. Enter the supported altitude/waypoint pair. Access STEP ALTS through VERT REV and read the current cruise reference. The guide's 360/ADABI/20 example places a step to FL360 twenty miles after ADABI using a route-relative point. It is a historical syntax example, not today's clearance. Inspect the accepted step point, time and distance and any generated along-track reference. [66, PDF pp. 420-423,191]
3. Inspect the temporary profile. Review S/C or S/D, resulting top-of-climb where provided, downstream T/D and the changed destination fuel/time. A rejected or ignored step can reflect available distance, position relative to cruise/descent or maximum altitude. Read its status rather than assuming that a stored pair is already part of the active prediction. STEP ABOVE MAX FL is information about feasibility, not an invitation to increase a limit. [66, PDF pp. 420-423,191]
4. Execute separately when cleared. The cited standard does not initiate the altitude change automatically at the step. Use the appropriate cleared FCU command and monitor the resulting FMA and level change. STEP NOW is a prompt tied to the plan; it is not an altitude clearance. If the step is not flown, read its removal/status and updated predictions instead of expecting a later invisible correction. [66, PDF pp. 420-423,191]
5. Revise through the step page. Delete or modify the intended pair and review TMPY before insertion. The guide warns against direct deletion near moving pseudo-waypoint rows because sequencing can affect which item is selected. After changing the step, re-read the cruise reference and T/D. Confirm that a deleted step has ceased affecting both the active profile and the PERF prediction displays. [66, PDF pp. 420-423,191]