op control
UK fast air to support ground troops in Afghanistan is provided by the Harrier GR9 / 7, who are on call 24 /7. But someone else controls the operation, the pilots don't get to decide when and where they go. Fast air allocation is done by NATO (ISAF) or the CAOC in Qatar. On any day (or night) at any time there may be several incidents in progress, the jets could get sent to any of them.