How Do I Know Preferred Routes?

I apologize in advance; I’m gonna come off pretty aggressively, but I’m actually so sick and tired of getting route amendments!

How the hell am I supposed to know the preferred routes? Is it luck? I honestly don’t know and it’s honestly really aggravating.

Is there a website I’m missing? I hate getting route amendments and having to ask ATC to ‘say again’ because I wasn’t ready to write down the waypoints correctly.

It depends on the country. Some countries such as the UK and New Zealand have standard routes published in the AIP. In some cases you can look on sites like FlightAware and find the real world route operated by a particular flight.

You can also check on Skyvector to see if a route “suggested” by Simbrief is sensible. Just yesterday Simbrief gave me a route that went the wrong way down a single direction airway!

If you aren’t able to write down an amended route in time, it’s acceptable to ask for it by text.

in europe two good websites are:
quite a big curated collection of routes, validated against IFPS

a real world flight database, I think mostly for flights within or at least to or from europe

Also in Simbrief you can look at the flightplans, if they have a eurocontrol symbol next to them, they should be valid. You also can validate against the IFPS in simbrief.

All of this is only applicable to the EU, I have not a lot of flight planning experience outside of the EU. One thing to add, some airports have SID-endpoints that are only available from some runways, so depending on the runway in use you get reroutings which you can minimize if you look at the weather and the SID charts to anticipate what you might get.

As David already hints at: SimBrief will sometimes have routes with additional forms of validation, such as the “Real World” routes commonly found for flights in the US, “NATS” routes inside the UK, or “Eurocontrol” for pretty much all of Europe - especially commonly flown routes between bigger airports will have this kind of extra validation and will generally be valid (though certain level ranges that SimBrief doesn’t know about may apply). Though I want to add that the “VATSIM” validation on SimBrief does not indicate a valid route and shouldn’t be relied upon.
Additionally, you can of course always try to find real world documentation on preferred routes or routing rules, though they may be somewhat hard to find and/or somewhat hard to put into practice if you don’t want to spend a lot of time planning your route (just look at the European Route Availability Document, e.g.).
Beyond that, you can look if websites like the Global Route Database or edi-gla have (recent) routes for the airport pair you are planning for and just copy them.
In Europe, you can always try to validate your plan against Eurocontrol’s route validator (go to the Network Operations Portal, scroll down to “Flight Planning” in the right-hand column, click on “Free Text Editor”, paste your flight plan string into the “FPL Data” field, press “Validate”, and see if it gives you any errors - if it does, look up the referenced error, more often than not a specific restriction in the Route Availability Document, build a new plan with that restriction in mind, and repeat the process until there are no more errors) - once you have validated a route without errors you can be 99.9% sure that your route will be fine on VATSIM.

It is also worth mentioning that actual reroutes on the network are often the result of pilots not briefing basic restrictions for their departure (e.g. certain departure fixes may only be available for certain type of aircraft or flights to certain destinations), activity of restricted airspaces (not always something you can plan for, though certainly worth trying to do and technically also required by the CoC), or just egregiously wrong routings (e.g. a route made up partly or even entirely of directs in airspaces where planning along airways is required), so these are things you might want to look into if you regularly encouter reroutes.
However, it is somewhat hard to know which restrictions are actually enforced on the network as this can vary greatly between different vACCs, controllers, and even the individual staffing and traffic situations, but you can try to find pilot briefing material for the vACCs managing the airspaces/airports you want to fly in/at and see if they provide any additional flight planning guidance.

And just on the off-chance that there may be a misunderstanding of what a route amendment is: if ATC tells you to proceed direct to one or multiple fixes (e.g. “proceed to MTR” or “proceed to DF401, thereafter DF416”), this is almost always a shortcut along your route and thus shouldn’t be taken as an indication that you planned an incorrect route. Additionally, getting a different SID or STAR than what you planned for also doesn’t necessarily indicate faulty route planning on your part as these procedures will usually be assigned based on the current operating concept of the airport, traffic levels, etc. and in many places you don’t even file them, though where filing a SID/STAR is required you should do so and pay attention to situations in which filing a specific SID/STAR may be mandatory for you or in which you are not allowed to file a specific SID/STAR in your flight plan. Even when routed to/via points that were not originally part of your planned route, it doesn’t necessarily indicate any error on your part and may just as well be a shortcut or a way for ATC to ensure the required separation, spacing, and compliance with procedures.
And ultimately, reroutes are not an uncommon occurrence even in real world aviation (though depending on where you are, a reroute may be prevented by flight plan filing systems that don’t accept invalid flight plans in the first place, but this is not something VATSIM simulates, at least for the time being), so getting a reroute every now and then should not cause you any concern. :wink: