PROG: NAVIGATION AND PREDICTION CROSSCHECKS
PROG is the progress page. At the gate, it gives us a useful pause in the entry work: does the cruise reference make sense, and does the available information agree with the aircraft we have prepared? We are looking for a coherent picture rather than trying to fill every available space. Some results require route, mass or other information before they can be calculated. [26, PDF p. 124]
The page can show the planned cruise reference, an optimum level and a recommended maximum when the required information is available. These give context to the plan. If an expected value looks surprising, revisit the input conditions before acting on it. If it is absent, first establish whether its prerequisites have been entered. A blank during incomplete preparation and a contradiction after complete preparation are different problems to understand. [26, PDF p. 124]
Another useful feature is BRG/DIST: bearing and distance to a selected reference. Bearing gives a direction; distance tells us how far away that reference is. We might use an airport, fix or appropriate runway reference to help understand the aircraft's position. The practical exercise uses the actual accepted reference rather than inventing a runway that has not been selected for the flight. [26, PDF p. 124]
Selecting a monitoring reference does not direct the aircraft to fly there. It gives us a measurement to compare with the wider navigation picture. Also keep direct distance to a reference separate from the distance along a route that includes turns and procedures. Both can be useful, provided we know which question each measurement answers. This is a page for adding context, not a shortcut around route review. [26, PDF p. 124]
After PROG, continue to PERF. The movement through DIFRIPPS is beginning to have a rhythm: establish information, inspect its effect, then use it in the next part of preparation. You can pause the simulator between those tasks during the early practice flights. There is time to make the connection between an input and the display that depends on it.
As the sequence becomes familiar, this small review will feel quite natural. You will recognise the pages and know which values deserve a second look. There is no examination clock running beside the keyboard. When the cruise/navigation picture makes sense and the monitoring reference is understood, continue to PERF. If something expected is still missing, pause long enough to understand its cause; the next page will wait.
IN PRACTICE: PROG: a useful check on the preparation
Before you begin: Route, cruise reference and mass/fuel inputs have been entered. Keep the OFP available so the page can be checked against an independent plan.
1. Review the cruise reference
Action. Press PROG and compare CRZ with the intended FL280 for the exercise. Inspect OPT and REC MAX when available, treating an unexpected result as a reason to revisit the aircraft, mass and planning inputs.
Check. The planned cruise reference is intentional and compatible with the information the aircraft is providing. The page is being read, not simply visited. [26, PDF p. 124]
2. Check navigation information
Action. Review the available GPS-primary/navigation-accuracy information. If it is inconsistent with completed alignment and the aircraft position, investigate the position/navigation pages before taxi.
Check. The information supports the navigation state you intend to use. A plausible route drawing has not replaced a position/accuracy check. [26, PDF p. 124] [26, PDF pp. 492-495] [26, PDF pp. 486-491]
3. Add a monitoring reference
Action. Enter EGLL as the BRG/DIST reference for the exercise, or use the appropriate actual reference. Read the resulting direction and distance as a direct reference measurement, not the remaining route distance.
Check. The bearing/distance reference is meaningful. The active flight plan and next active waypoint have not been changed by this monitoring entry. [26, PDF p. 124]
4. Account for an empty prediction
Action. If an expected value is absent, first check that its route, cruise and mass inputs are complete. Confirm which flight phase/page you are reviewing before treating a blank as a system failure.
Check. Missing inputs and an unexplained computation problem are distinguished. You have not supplied a convincing-looking number just to fill the space. [26, PDF p. 124] [26, PDF p. 123]
5. Recognise the current build’s limitation
Action. If NO-COMPUTATION persists despite coherent inputs, record the conditions and consult the current Fenix issue information. Some V3 prediction cases were reported in the 24–25 October 2026 staff update.
Check. A known-issue check supports diagnosis, but does not automatically excuse every missing prediction or justify changing correct mass and route data. [42]
Complete when: Cruise/navigation information is credible, a monitoring reference is understood, and any missing prediction has been investigated without inventing data.