Why does ATC sometimes use runways that differ from real-world ops?

Now that we inject and control our own traffic, we’ve also assumed responsibility for all operational decisions at the airport. That includes which runways are active and when a directional change takes place. This isn’t optional—here’s why:

1. Authority Has to Match Control

In the real world, operational direction is set jointly between the tower, TRACON, and the airport operations director, often 30–45 minutes in advance. Since we’re the entity creating and sequencing traffic flows in the sim, we also have to be the one making the operational calls. If we ceded that to “whatever ATL is doing right now in real life,” the result would be chaos because we’d have no way to align our traffic management with real-world decision cycles.

2. Runway Direction Is More Than Wind

Many sim pilots assume the active runway is simply “the one aligned with the wind.” That’s not how it works. Real-world ATC considers:

• Noise abatement and community procedures.
• Arrival/departure balancing to maximize throughput.
  
• Airspace complexity and sector loading.
  
• Runway occupancy times and taxiway configurations.
• Weather forecasts for the next few hours
• Last time the operational direction shifted
• Calm-wind thresholds (often 5–10 knots) that allow a tailwind if it keeps the airport stable.

We follow the same principles—but we must apply them in the context of our traffic, not theirs.  This means, yes, it is ENTIRELY LIKELY you could be assigned a landing on a runway that has a tail-wind. (The same happens in real life all the time).  If your aircraft is unable to accept the parameters of the landing, you can do what a real-world pilot would do in that scenario:  Divert.

3. Direction Shifts Are Major Events

At large airports, flipping the operation (north → south, east → west) is not instantaneous. It takes 30–45 minutes of coordination, rerouting of departures and arrivals, and reconfiguring ground movement. Pilots in the sim don’t see that machinery. If we tried to shadow real-world shifts in real time, we’d end up whipsawing traffic mid-approach, destroying flow predictability. Instead, we determine when a shift is warranted and execute it in a way that keeps our injected traffic orderly.

4. Real-World Ops Don’t Map Cleanly to the Sim

Take ATL as an example. In reality, ATL may be running “north” with a 90° crosswind, while we’re running “south” with the same crosswind. Both are valid operational choices under FAA guidance—but in the sim, our decision is the only one that matters because we’re the only ones controlling the injected traffic. There is no FAA ops director calling us to say, “expect a direction flip in 30 minutes.” That authority resides here.

5. Predictability Beats “Mirror Reality”

If we slavishly mirrored the real airport, we’d constantly conflict with our own injected traffic flows. By making the calls ourselves, we maintain predictable, stable operations that mirror the principles of real-world ATC without being shackled to decisions we can’t coordinate with.

The Bottom Line

Because we control the traffic, we must also control the airport. We model the same decision-making principles that govern real-world ops, but the authority to decide when, how, and why to shift directions lies with us as the controlling ATC. Mirroring reality is secondary to maintaining a safe, orderly, and believable environment in the sim.