Many services for flight planning provide ICAO options. I played around with a couple to see which ones are the most user friendly and caught errors. All of these services are free.
DUATS—This is my favorite ICAO flight planning and filing service. To navigate to the ICAO flight plan area, select “Flight Planning,” “File a Flight Plan,” then “ICAO.” The form closely matches the FAA From 7233-4. Drop down menus make selections easy and clicking a question mark provides an explanation of the item to help completing the form. A drop down menu allows selection of GNSS augmentation (WAAS) and automatically adds the correct notation to the remarks section. Error checking prevents entry of equipment codes without associated remarks. Interestingly, it doesn’t check LPV approach capability with having a GNSS. Otherwise, DUATS is a user-friendly interface for getting used to ICAO FPs.
