Using a data flow diagram, capture the data and functional requirements for monitoring the entry, exit, and traversal of aircraft in a busy airspace. Aircraft entering the space are sensed by the Radar input; the Comm input identifies aircraft that leave the space. The current contents of the space are maintained in the data area AirspaceStatus . A detailed log or history of the space usage is kept in the AirspaceLog storage. Air - traffic control personnel can request the display of the status of a particular aircraft through the Controller input.