Change or reset the FS2004 simulation rate, return to normal 1× speed, and fix R, plus or minus keyboard controls that do not respond.
To change the simulation rate in Microsoft Flight Simulator 2004, press R, then press + to speed up time or - to slow it down. To reset it precisely, choose Normal under Options > Simulation Rate; this returns FS2004 (FS9) to standard 1× speed without guessing how many key presses are needed.
Change the FS2004 simulation rate with the keyboard
The default control is a key sequence: press R first, followed by + or -.
- Give FS2004 keyboard focus. Click inside the simulator window if another program was previously active.
- Select simulation rate. Tap
R; do not treat it as a modifier that must be held down. - Adjust the rate. Press
+to increase it or-to decrease it. Repeat the sequence as required and watch the temporary on-screen rate message. - Resume at normal speed. Select Normal from the menu if you are unsure whether the rate is above or below 1×.
Our reference for FS2004's default key bindings covers the other standard flight, view and simulator controls.
How do I set FS2004 back to normal speed?
Select Options > Simulation Rate > Normal to restore exactly 1× simulation speed. If the menu bar is hidden, press Alt to reveal it.
You can also use the keyboard, but the direction depends on the present rate. Use R followed by - when running faster than normal, or R followed by + when running at a fractional rate. A common mistake is pressing minus repeatedly when FS2004 is already below 1×.
Why do R, plus and minus not change the rate?
If the menu changes the rate but the shortcut does not, the problem is usually the keyboard layout, window focus or a reassigned command rather than the simulator clock.
- Use the keys as a sequence: press
R, release it, and then press the adjustment key. - Try the numeric keypad: on keyboards where
+shares the=key, use the modifier required to type plus or try the keypad plus key. - Check the assignments: open Options > Controls > Assignments and verify the simulation-rate increase and decrease commands. Laptop users without keypad keys can assign alternatives there.
- Check for pause: changing the rate will not make a paused aircraft move. If FS2004 shows that it is paused, use the pause command, which is
Pby default. - Test without an add-on intercepting keys: if the commands work in a default aircraft but not a complex add-on, inspect that add-on's keyboard or panel controls.
Is simulation rate the same as frame rate?
No. Simulation rate changes how quickly time and the flight model advance, while frame rate controls how frequently FS2004 draws the picture.
| Setting | What it changes | Normal use |
|---|---|---|
| Simulation rate | The simulator clock, aircraft motion and other time-dependent processes | Use 1× for normal flying; higher rates compress cruise time |
| Frame rate | The number of images drawn each second | Balance visual smoothness against computer performance |
Changing the simulation rate will not cure stuttering or low FPS. For that separate setting, use our guide to choosing an FS2004 frame-rate target.
When should I avoid accelerated simulation rates?
Use rates above 1× mainly during stable cruise, then return to Normal before major turns, descent, approach or landing. Autopilots, AI traffic and complex add-ons can miss events, overshoot targets or become unstable when the rate is high, particularly when the computer is already struggling to maintain smooth performance.
Fuel burn, distance travelled, weather progression and the simulator clock continue according to simulated time. If an aircraft or add-on behaves unexpectedly, reset the rate to Normal before changing aircraft settings or diagnosing a fault.