According to AS3 documentation:
Gets and sets the frame rate of the stage. The frame rate is defined as frames per second. By default the rate is set to the frame rate of the first SWF file loaded. Valid range for the frame rate is from 0.01 to 1000 frames per second.
Note: An application might not be able to follow high frame rate settings, either because the target platform is not fast enough or the player is synchronized to the vertical blank timing of the display device (usually 60 Hz on LCD devices). In some cases, a target platform might also choose to lower the maximum frame rate if it anticipates high CPU usage.