Figure 3: TGUI Timeline

This figure shows a portion of one of the timelines found on 
the Planview Graphical User Interface (PGUI).

The timeline runs vertically.  At the bottom of the timeline are
the letters "FDR" which means that this is a feeder gate or
meter fix timeline. The bottom of the timeline represents
the current time.  Tick marks on the timeline represent minutes
in the future.  Every fifth tick mark has a number which represents
the number of minutes after the hour.

The timeline has a left side and a right side.  At the bottom of
each side is an abbreviation of the meter fix that this timeline
represents.  In this case, the meter fix is BP.  The bottom also
shows that this timeline displays aircraft destined to all
runways.  The left side show various aircraft callsigns in green.
The location of the aircraft callsign on the timeine represents
its estimated time of arrival (ETA) at the meter fix.  Each aircraft's
callsign is accompanied by a symbol indicating the weight class of
the aircraft.  The right side shows the same aircraft callsigns.
Some of these are blue and others are yellow.  The position of
a callsign represents the schedule time of arrival (STA) at the
meter fix.  Blue callsigns means that the aircraft's STA is frozen,
while yellow indicates that the aircraft's STA is unfrozen.