Another example is an offset phantom waypoint, which  is a point in space formed by a bearing and distance from  NAVAIDs, such as VORs, VORTACs, and TACANs, using a  variety of navigation systems.  Traffic Management Advisor (TMA). A software suite that  helps air traffic controllers to sequence arriving air traffic.  Transition Altitude (QNH). The altitude in the vicinity of an  airport at or below which the vertical position of an aircraft  is controlled by reference to altitudes (MSL).  User Request Evaluation Tool (URET). The URET helps  provide enhanced, automated flight data management.  URET is an automated tool provided at each radar position  in selected en route facilities. It uses flight and radar data  to determine present and future trajectories for all active  and proposed aircraft flights. A graphic plan display  depicts aircraft, traffic, and notification of predicted  conflicts. Graphic routes for current plans and trial plans  are displayed upon controller request. URET can generate  a predicted conflict of two aircraft, or between aircraft  and airspace.  Transition Height (QFE). Transition height is the height in  the vicinity of an airport at or below which the vertical  position of an aircraft is expressed in height above the  airport reference datum.  Transition Layer. Transition layer is the airspace between  the transition altitude and the transition level. Aircraft  descending through the transition layer will set altimeters  to local station pressure, while departing aircraft climbing  through the transition layer will be using standard altimeter  setting (QNE) of 29.92 inches of Mercury, 1013.2 millibars,  or 1013.2 hectopascals.  Transition Level (QNE). The lowest flight level available for  use above the transition altitude.  Vertical Navigation (VNAV). Traditionally, the only way  to get glidepath information during an approach was to  use a ground-based NAVAID, but modern area navigation  systems allow flight crews to display an internally  generated descent path that allows a constant rate descent  to minimums during approaches that would otherwise  include multiple level-offs.  Turn Anticipation. The capability of RNAV systems to  determine the point along a course, prior to a turn WP,  where a turn should be initiated to provide a smooth path  to intercept the succeeding course and to enunciate the  information to the pilot.  Vertical Navigation Planning. Included within certain STARs  is information provided to help you reduce the amount of  low altitude flying time for high performance aircraft, like  jets and turboprops. An expected altitude is given for a key  fix along the route. By knowing an intermediate altitude in  advance when flying a high performance aircraft, you can  plan the power or thrust settings and aircraft configurations  that result in the most efficient descent, in terms of time,  fuel requirements, and engine wear.  Turn WP (Turning Point). A WP that identifies a change from  one course to another.  Universal Communications (UNICOM). An air-ground  communication facility operated by a private agency to  provide advisory service at uncontrolled aerodromes and  airports.  Visual Approach. A visual approach is an ATC authorization  for an aircraft on an IFR flight plan to proceed visually to  the airport of intended landing; it is not an IAP. Also, there  is no missed approach segment. When it is operationally  beneficial, ATC may authorize pilots to conduct a visual  approach to the airport in lieu of the published IAP. A visual  approach can be initiated by a pilot or the controller.  User-Defined Waypoint. User-defined waypoints typically  are created by pilots for use in their own random RNAV  direct navigation. They are newly established, unpublished  airspace fixes that are designated geographic locations/  positions that help provide positive course guidance for  navigation and a means of checking progress on a flight.  They may or may not be actually plotted by the pilot on  en route charts, but would normally be communicated to  ATC in terms of bearing and distance or latitude/longitude.  An example of user-defined waypoints typically includes  those derived from database-driven area navigation (RNAV)  systems whereby latitude/longitude coordinate-based  waypoints are generated by various means including  keyboard input, and even electronic map mode functions  used to establish waypoints with a cursor on the display.  Visual Climb Over the Airport (VCOA). An option to allow  an aircraft to climb over the airport with visual reference  to obstacles to attain a suitable altitude from which to  proceed with an IFR departure.  Waypoints. Area navigation waypoints are specified  geographical locations, or fixes, used to define an area  navigation route or the flightpath of an aircraft employing  area navigation. Waypoints may be any of the following  types: predefined, published, floating, user-defined, fly-by,  or fly-over.  G-11 