RTE Airway Entry & the "NOT IN DATABASE" Fix

intermediate
📍 Route: KLAX → … → LAS (via J146)⏱ ~4 minutes📊 8 steps

Fix the two errors every 737 pilot hits when entering an airway on the CDU RTE page — "NOT IN DATABASE" (unknown airway) and "INVALID ENTRY" (a waypoint that isn't on the airway). Learn to read each message and insert J146 correctly on a Los Angeles to New York route.

Start this scenario

Open the SimTuts 737 CDU trainer and select “RTE Airway Entry & the "NOT IN DATABASE" Fix” from the scenarios list to walk through it step-by-step on the simulated keypad.

Open trainer →

Step-by-step: RTE Airway Entry & the "NOT IN DATABASE" Fix

  1. Set up a route to work with. Press the RTE key, then type KLAX into the scratchpad and press 1L to enter the ORIGIN.

    KLAX is Los Angeles. The RTE page is where the route begins — origin on the left, destination on the right. The FMC needs both before it can build the enroute legs.

  2. Type KJFK and press 1R to enter the DEST (destination).

    KJFK is New York JFK. With origin and destination set, the FMC has the two endpoints — but no path between them yet. You build that path on the second RTE page using airways.

  3. Open the second RTE page, where airways are entered on the real 737. Press 6L (<RTE 2).

    On the real Boeing 737 the route is built on the RTE page using VIA/TO columns — the airway goes under VIA (left), the exit waypoint under TO (right). The LEGS page only shows the expanded leg sequence; it does not accept airway entries.

  4. Let's reproduce the first error. Type J999 (an airway that doesn't exist) into the VIA column: type J999 and press 1L. The CDU rejects it with NOT IN DATA BASE.

    NOT IN DATABASE means the FMC has no airway with that exact name in the current AIRAC cycle. Almost always it's a typo (J999 vs J99), an airway outside your database coverage, or a victor/jet-route prefix mistake (V vs J). The fix is simply to enter the correct airway identifier from your flight plan.

  5. The real airway is J146. You don't need to clear the message — just type J146 (it replaces the error) and press 1L to stage it in the VIA column.

    J146 is a real high-altitude jet route across the western US. Once staged, the CDU shows it in cyan (a pending change) and waits for the TO waypoint that says how far along it you'll travel before it becomes part of the active route.

  6. Now the second error. The waypoint where you leave the airway must actually lie on it. Type DEN (Denver — not on J146) into the TO column: type DEN and press 1R. The CDU rejects it with INVALID ENTRY.

    INVALID ENTRY here means the TO waypoint exists, but it isn't one of the fixes that define this airway — the real 737 FMC shows INVALID ENTRY for an airway that doesn't contain the entered waypoint (FCOM §11.40.18). The fix is to pick a waypoint from the airway's own sequence — check your flight plan for a valid exit fix.

  7. LAS (Las Vegas) is on J146. Type LAS (it replaces the error) and press 1R to set it as the airway exit in the TO column.

    LAS is an early fix on J146, so the FMC will follow the airway from KLAX as far as LAS. With both the airway (VIA J146) and a valid exit (TO LAS) staged, the route shows MOD and the EXEC prompt lights so you can commit the change.

  8. Press 6R to EXEC the staged airway. The cyan pending route becomes the active flight plan.

    EXEC commits any pending route change on the Boeing FMC — nothing you stage takes effect until you press it (the real aircraft also has a dedicated EXEC key). That's the whole RTE airway workflow, and you now know how to decode both NOT IN DATABASE and INVALID ENTRY when they appear.

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