Route Correction — Fix a Mistyped Destination
intermediateThe destination is wrong on the RTE page. Overwriting a field you already filled is a distinct skill from filling it.
What this scenario covers
Correcting an entry on the 737 means typing the new value into the scratchpad and line-selecting it over the old one, then executing. Because the change is staged, you get to see the modified route before it becomes real — and can erase it if it is not what you wanted.
The scenario starts with a mistyped destination in place, so the exercise is the overwrite and the verification, not the original typing.
How it applies in flight ops
Reroutes and destination changes are ordinary events: weather, a diversion, a slot, a tail swap. What makes them safe is that the crew treats a changed field as invalidating everything downstream of it until they have looked.
The cross-check is against the source document — the OFP or the clearance — and never against memory. A well-formed wrong entry is indistinguishable from a right one on the screen.
Start this scenario
Open the SimTuts 737 CDU trainer and select “Route Correction — Fix a Mistyped Destination” from the scenarios list to walk through it step-by-step on the simulated keypad.
Open trainer →Step-by-step: Route Correction — Fix a Mistyped Destination
- Press the RTE page key to open ROUTE.
Real-world scenario: dispatch sends a corrected OFP, or ATC issues a reroute clearance. You need to overwrite an entry that's already there. The 737 CDU requires CLR-and-retype, not edit-in-place.
- Type KJFK and press 1L for ORIGIN.
Same as a normal route entry. The mistake comes next.
- Now type EGKK (London Gatwick) and press 1R for DEST. (We'll fix this in the next step — this is the wrong airport.)
EGKK is London Gatwick, not Heathrow. A common mistake when copying from an OFP — adjacent codes, similar destinations.
- You realise the OFP says EGLL, not EGKK. To fix it: press CLR (or Backspace) until the scratchpad is empty, type EGLL, then press 1R again to overwrite DEST.
On the 737 CDU there is no edit-in-place. Pressing an LSK with new scratchpad content overwrites whatever was there. This is how every correction works on the box, including ATC reroutes.
- Type BAW178 and press 2R for FLT NO to confirm the route is now correct.
Sanity check — fixing one field doesn't reset the others. The flight number, CO ROUTE, and any other entered data persist.
What to take away
- Overwrite by line-selecting the new value over the old, then EXEC.
- The staged modification lets you see the change before committing.
- Everything downstream of a changed field needs re-checking.
- Verify against the paperwork, not against what you intended to type.
The rest of Flight Plans & Routing
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beginnerLondon to Paris on the 737: RTE, PERF INIT and TAKEOFF REF, the complete short-haul setup in one sitting.
📍 EGLL → LFPG⏱ ~5 min📊 9 stepsSID & STAR: KPHX → KLAS
intermediatePhoenix to Las Vegas: enter the route, then program a departure and an arrival from the DEP/ARR page.
📍 KPHX → KLAS — SID/STAR practice⏱ ~6 min📊 5 stepsRTE Airway Entry & the "NOT IN DATABASE" Fix
PremiumintermediateTwo error messages every 737 pilot meets on the RTE page — NOT IN DATABASE and INVALID ENTRY — and what each one is actually telling you.
📍 KLAX → … → LAS (via J146)⏱ ~4 min📊 8 stepsClosing a LEGS Discontinuity
PremiumbeginnerThe box prompts on the LEGS page are a route discontinuity. Here is what the FMC is asking for and how to close the gap.
📍 EGLL → DVR → LFPG⏱ ~4 min📊 4 steps
Background reading
- GuideThe Boeing 737 CDU / FMC Explained: Every Page
What is the 737 CDU and FMC? A plain-English guide to every Boeing 737 CDU page plus the EXEC/MOD workflow. Practice free in our CDU trainer.
- GuidePMDG 737 FMC Tutorial: Program Your First Flight Plan Step by Step
Program the PMDG 737 FMC from scratch: IDENT, POS INIT, ROUTE, PERF INIT, takeoff speeds, and VNAV setup. Every CDU page explained with the exact inputs.
- GuidePMDG 777-300ER Cold and Dark Startup: Complete Step-by-Step Guide
Battery to takeoff in the PMDG 777-300ER with interactive checklist. FMC setup, GE90 engine start, and the stabiliser trim that prevents tail strikes.