In order to develop add-ons for Flight Simulator X, you should use the matching SDK from the table below.

The recommended approach is to use the Flight Simulator X: Acceleration Expansion Pack SDK to develop add-ons that are strictly for use with the Acceleration Expansion Pack, and to use the Flight Simulator X SDK SP2 for add-ons that are for all Flight Simulator X users. However the latter does require that the users upgrade to Flight Simulator X SP2 – which is a free upgrade. This is recommended as the SP2 version of Flight Simulator X has the latest performance improvements and fixes, and its matching SDK has the latest tools – with many fixes to these too.

If it is important to support users who might not upgrade to SP2, then use the matching SDK from the following table, but be aware that performance and other improvements to both the simulator and the SDK tools are being omitted by adopting this approach.

Important: If the SDK and product version do not match, some tools will not run.