In an effort to better support our customers and our community, we're releasing an update to Microsoft Flight Simulator X: Service Pack 1 (SP1). We had three main goals in developing this update:

• Improve performance
• Fix bugs blocking third-party add-ons
• Fix egregious bugs

In addition to updating the run-time FSX executable for performance and general bug fixing, we've also made some significant changes to the Software Development Kit (SDK) and related run-time components for improving the third party extensibility mechanisms.

You can read more about SDK SP1A in this article.

You can download SDK SP1A itself here.