How do I use time compression in FS2004?

To use time compression in Microsoft Flight Simulator 2004 (FS9), press R, release it, then press + to increase the simulation rate or - to decrease it. Repeat the adjustment until the on-screen rate is correct; return to 1x before descent, approach, landing or detailed ATC work.

How to change the simulation rate in FS2004

1. Stabilise the aircraft: establish level flight manually or let the autopilot settle before accelerating time.
2. Select simulation rate: press and release R. This is a sequence, not a key combination that must be held down.
3. Increase or decrease it: press + to raise the rate or - to lower it. Repeat as required while watching the rate shown on screen.
4. Return to normal speed: reduce or increase the setting until it reads 1x.

On some keyboards, the plus sign shares the equals key and requires Shift; a numeric-keypad plus key may also work. If neither does, check the Increase Selection and Decrease Selection assignments. Our FS2004 control reference explains the default shortcuts and assignment screen.

Do not keep pressing minus without checking the display. FS2004 supports slower-than-normal simulation, so it is possible to pass below 1x rather than resetting automatically.

Which time-compression rate should I use?

The safest rate depends on the aircraft, weather, traffic and how much manoeuvring lies ahead.

Increase the rate one step at a time. A complex add-on aircraft may tolerate less acceleration than a default FS2004 aircraft because its gauges or systems can depend on their own timing logic.

Can the autopilot fly under time compression?

Yes, but high simulation rates can make the FS2004 autopilot overcorrect, oscillate or miss an altitude capture.

First establish the desired heading, altitude and vertical mode at 1x. Raise the rate gradually, then reduce it before turns, turbulence, top of descent or any major configuration change. If the aircraft begins banking or pitching repeatedly, return to 1x immediately rather than trying to correct it while time remains accelerated.

Time compression does not keep an aircraft on course by itself. For long cruise legs, use a stable autopilot mode and verify the route; our guide to following a route with the FS2004 GPS covers the default navigation unit.

Does time compression affect fuel, ATC and flight time?

Time compression advances simulated time, aircraft movement and normal fuel consumption together.

At 4x, one simulated hour takes roughly 15 minutes of real time, while the indicated airspeed remains the aircraft's simulated airspeed. Daylight, navigation progress and most systems tied to simulator time also advance more quickly. Some third-party gauges may use different timing methods, so monitor them after changing the rate.

FS2004's ATC audio and traffic sequencing do not always remain comfortable at high rates. Radio calls may arrive too quickly, and an aircraft can pass a waypoint, descent point or assigned altitude before there is time to respond. Use 1x for hand-offs, vectors, traffic-pattern work and the entire approach.

Why is FS2004 time compression not working?

The usual cause is a changed keyboard assignment or pressing the keys as a chord instead of a sequence.

• Press and release R before pressing plus or minus.
• Try the plus/equal key and the numeric-keypad plus key if the keyboard has both.
• Check that Increase Selection and Decrease Selection still have assignments in the Controls settings.
• Disable or reassign any add-on utility that intercepts the same keys.
• Test with a default aircraft, as a complex add-on may limit accelerated simulation or become unstable under it.