SEC F-PLN: PREPARE THE ALTERNATIVE BEFORE IT IS NEEDED
SEC F-PLN is the secondary flight plan, a place to prepare an alternative while keeping the active route as the working flight. COPY ACTIVE gives us a useful starting point. We can then prepare a specific change, such as a different departure option, and inspect it before we need it. A few minutes of orderly work at the stand can save a much more demanding piece of typing later. [26, PDF p. 121] [26, PDF pp. 427-438]
The two plans have different roles. The active plan describes the route currently in use; the secondary plan holds the prepared alternative. Copying or editing the spare does not automatically make it active. Keep reading the page identity while working, especially when the two routes share many waypoint names. Familiarity is helpful, but it can make two similar-looking lists surprisingly easy to confuse. [26, PDF p. 121] [26, PDF pp. 427-438]
For Frankfurt, a prepared return can also be useful. It still needs a real runway or approach choice, correct leg order, understood discontinuities and appropriate performance assumptions. The practical exercise uses a genuine planned alternative supported by current information; it does not invent a return runway to make the spare look complete. The aim is a route with a clear purpose and remaining tasks that are understood. [26, PDF pp. 427-438]
Review the alternative with the same care as the original. Check the connection from its departure or arrival procedure to the intended remaining route, and consider what a later change would mean for performance preparation. A secondary plan is useful because that thinking has already begun. Merely storing another unexamined list of fixes postpones the work to the moment when attention may be in shorter supply. [26, PDF pp. 427-438]
Activation is the separate decision to make the alternative the working plan. Before doing it, confirm the clearance, the aircraft's position and the first intended leg. A route that was sensible when prepared still needs to fit the aircraft's situation when activated. The practical workshop leaves the spare secondary until that deliberate decision is required. [26, PDF pp. 427-438]
After an actual activation, look at the ND, the active flight-plan sequence and the guidance modes. Establish what is now active and how the aircraft is being guided towards it. The stored plan is there to reduce workload, while the display checks tell us what the aircraft will actually do with the change. That is the useful kind of preparation: a ready alternative together with a clear way to bring it into use. [26, PDF pp. 427-438]
IN PRACTICE: SEC F-PLN: prepare an alternative without changing the active route
Before you begin: The active route has been checked. For this workshop use a genuine planned departure-runway alternative supported by current charts; preparing a full return is a separate, equally deliberate route task.
1. Begin from a verified active plan
Action. Read the active departure, destination and initial route once more. Correct any unresolved active-plan error before copying it into the secondary plan.
Check. The spare will begin from a known, checked baseline rather than reproduce an error in a second place. [26, PDF p. 121] [26, PDF p. 128]
2. Copy the active route
Action. Press SEC F-PLN and use COPY ACTIVE. Open the secondary flight plan and inspect its endpoints and initial legs.
Check. The secondary copy represents the active route at the time of copying. Preparing it has not itself activated it. [26, PDF pp. 432-435]
3. Make the intended secondary revision
Action. Within SEC F-PLN, open the departure airport’s lateral revision and prepare the actual alternative runway/SID/transition. Keep the alternative tied to the current enroute connection and charted restrictions.
Check. The secondary route now represents the specific departure option you intended to prepare. Its procedure names and connection have been checked independently. [26, PDF pp. 432-435] [26, PDF pp. 113-114]
4. Inspect the whole secondary connection
Action. Scroll its revised departure and several enroute legs, checking discontinuities, duplicate fixes and restrictions. Review the route display where available and identify any performance work a later runway change will require.
Check. The spare is more than a different runway name. Its route construction and the remaining work are understood. [26, PDF pp. 432-435] [26, PDF pp. 142-165]
5. Confirm that the active route stayed active
Action. Return to ordinary F-PLN and compare it with the original departure and initial legs. Then reopen SEC F-PLN to confirm the intended alternative is still there.
Check. The active flight remains the original one; the reviewed alternative remains secondary. The two plans have not been confused during editing. [26, PDF pp. 432-435]
6. Keep activation as a separate operation
Action. Identify the ACTIVATE SEC function without selecting it merely to finish this drill. Before an actual activation, confirm the intended clearance, aircraft position, first leg and subsequent guidance, then review the new active route.
Check. You know what activation will replace and what must be checked afterwards. A prepared spare has not silently become the working route. [26, PDF pp. 436-438]
Complete when: A reviewed secondary alternative is available and the original active route is intact. Activation remains a separate decision tied to the intended clearance and aircraft position.