What is FSX Acceleration, and do you need it?
FSX Acceleration is Microsoft’s official expansion for boxed Flight Simulator X. It adds three aircraft, new missions and activities, while also updating the simulator to the Service Pack 2 code level. You do not need it for FSX to run, but some add-ons require it. FSX: Steam Edition already includes its content and updates.
What does FSX Acceleration add?
Acceleration combines an expansion pack with a major platform update for FSX Standard or Deluxe. Its main additions are:
- Three default aircraft: the F/A-18A Hornet, EH-101 helicopter and P-51D Mustang.
- Extra missions and activities involving aircraft carriers, helicopter sling loads and air racing.
- Service Pack 2-era fixes, simulator interfaces and multiplayer improvements used by many later add-ons.
- The legacy
DX10 Previewrenderer, which can improve some visual effects but may cause texture or lighting problems with older add-ons.
The expansion originally promoted online racing and other multiplayer features, but its old GameSpy matchmaking service no longer operates. The aircraft, missions, offline features and add-on compatibility remain the useful parts.
Do you need FSX Acceleration?
Your FSX edition and the requirements of your add-ons determine whether Acceleration is necessary.
| FSX installation | Is Acceleration needed? | Correct approach |
|---|---|---|
| Boxed FSX Standard or Deluxe | Optional | Install it for its aircraft and missions, or when an add-on explicitly requires Acceleration. |
| Boxed FSX with standalone SP2 | Not for basic updates | SP2 provides the main platform update, but not the Acceleration aircraft, missions and expansion-specific components. |
| FSX Gold Edition | Already supplied | Gold includes Deluxe and the separate Acceleration disc; install that disc after the main simulator. |
| FSX: Steam Edition | No separate installation | Steam Edition already includes Acceleration-era content and updates. Our explanation of the practical differences between Steam Edition and boxed FSX covers the remaining compatibility distinctions. |
Never run the boxed Acceleration installer over FSX: Steam Edition. It is unnecessary and may confuse the installation by targeting boxed-FSX registry entries and folders.
Is FSX Acceleration the same as Service Pack 2?
No. Acceleration includes the Service Pack 2-level simulator update, but standalone SP2 does not include the Acceleration expansion content.
| Feature | Standalone SP2 | Acceleration |
|---|---|---|
| Core SP2 fixes and interfaces | Yes | Yes |
| F/A-18A, EH-101 and P-51D | No | Yes |
| Acceleration missions and activities | No | Yes |
| Usually satisfies “SP2/Acceleration” requirements | Yes | Yes |
| Satisfies an explicit “Acceleration required” notice | No | Yes |
This distinction prevents a common mistake: installing standalone SP2 after Acceleration. Acceleration already contains the required update, so the standalone SP2 package should not be layered on top of it.
What does “Acceleration required” mean for an add-on?
An add-on marked FSX SP2/Acceleration will normally work with either standalone SP2 or Acceleration, while one marked specifically Acceleration required may depend on expansion aircraft, gauges, carrier features or other files absent from SP2.
FSX: Steam Edition normally satisfies an Acceleration requirement. Some old installers still fail because they search only for the boxed edition’s registry information. If that happens, select the installer’s Steam option or point it to the Steam FSX folder when permitted; do not install the boxed expansion as a workaround.
How should you install Acceleration on boxed FSX?
The least troublesome boxed-FSX sequence is the base simulator, Service Pack 1 and then Acceleration.
- Install boxed FSX and launch it once so that the simulator creates its configuration folders.
- Install Service Pack 1. We explain why SP1 comes before later boxed updates and how to confirm it installed correctly.
- Install Acceleration and launch FSX again. Do not install standalone SP2 afterwards because Acceleration already incorporates that update level.
- Add aircraft and scenery afterwards. Installing the expansion over a heavily modified simulator can overwrite default files or expose add-on compatibility problems.
If standalone SP2 is already present and the Acceleration installer refuses to continue, remove SP2 through Windows Installed apps or Programs and Features rather than deleting simulator files manually. For the complete sequence and recovery options, follow our boxed FSX update order, including what Acceleration replaces.
How can you tell whether Acceleration is installed?
The simplest check is the default aircraft selection menu: an installation containing the F/A-18A Hornet, EH-101 and P-51D normally has the Acceleration content. Steam Edition includes these by design, while a boxed installation with only standalone SP2 does not.
For a boxed user, Acceleration is worthwhile when you want those aircraft and missions or have an add-on that explicitly depends on it. If the simulator is already stable on SP2 and every add-on accepts SP2/Acceleration, the expansion is not essential.