Just a few steps showing you how to setup AIR 3.3 in Flash Builder 4.6 on Windows:

1. Download AIR 3.3 SDK – air-sdk-download
2. Navigate to your SDKs folder (under Flash Builder 4.6 installation directory).
   
   • For 64x Windows: C:Program Files (x86)AdobeAdobe Flash Builder 4.6sdks
   • For 32x Windows: C:Program FilesAdobeAdobe Flash Builder 4.6sdks
3. Clone SDK 4.6 folder and rename it (Example: 4.6.0_AIR_3.3)
4. Extract AIR SDK zip inside the new folder and overwrite all matches.
5. Download Playerglobal SWC for Flash Player 11.3
6. Go to /frameworks/libs/player/ inside your new SDK folder, create a new folder and name it “11.3” and place the SWC file from the previous step there. Don’t forget to rename it to playerglobal.swc
7. Go back to 4.6.0_AIR_3.3 folder and open flex-sdk-description.xml
   file. Change <name> value to something more meaningful and different from the current one. I preffer using Flex 4.6 (AIR 3.3)
8. Open Flash Builder, go to Window->Preferences->Flash Builder->Installed Flex SDKs and add the new folder.

If you want to move an old project from AIR 3.1 or 3.2 to AIR 3.3 open its application.xml file and change the namespace at the top to match AIR 3.3. It should look like this:

<application xmlns="http://ns.adobe.com/air/application/3.3">

For every project you create and uses AIR 3.3 don’t forget to add -swf-version=16 to the compile arguments right after -locale en_US

External links:

• AIR 3.3 SDK
• Playerglobal 11.3 SWC
• Flash Player 11.3 (AIR 3.3) release notes