Start Permission and “Three Phase Start
From FIS Freestyle wiki
3043.4.2.4 Start Permission and “Three Phase Start

Start permission and starting time control at OWG, WSC and WC, competitions will be determined by means of a three-colored (red-yellow-green) signal and a digital display which are connected and run by a adjustable program. During the red phase (start preparation), the clock does not run and is set at 15 seconds. During next yellow phase, (5 seconds) the clock starts to run down from 15 seconds and then switches after 10 seconds to the green phase. The starting time will be finished after 15 seconds and the display then shows ‘0’. At ‘0’, the light automatically changes back to red and the starting procedure for the next competitor begins.
3043.4.2.5 It is the competitors’ responsibility to be ready at the start when their starting number is called. The competitor has to leave the start after the start signal has been given. If the competitor has not left the start by the end of the start time, the hill will automatically be closed.
3043.4.2.6 During the starting procedure, the competitor must have the opportunity to clearly observe the automatic countdown display (e.g. a programmable digital clock)
3043.4.2.7 The competitor has to start within the start time. If the start signal is interrupted during the competitors’ starting period for any reason, for example unstable weather conditions, the starting process will begin again.
Return to 3043.4 Start Commands, 3043, International Competition Rules or Freestyle Skiing or onto 3044