Suspend mode. For some FMS/RNAV units, the name  used to describe the nonsequencing mode when it has been  automatically set by the computer, or pilot. Terrain system.  Any cockpit system that provides the pilot  with a pictorial view of surrounding terrain, and in some  cases, visual and/or auditory alerts when the aircraft is  operating in close proximity to terrain. TIS.  See traffic information service. Top-of-descent point.  The point that the RNAV computer calculates to be the ideal location at which to begin a descent  to the planned crossing restriction, given the descent speed  and rate that has been entered by the pilot. TA.  See traffic advisory. Tape display. A vertical display format used to portray,  for example, airspeed and altitude on many primary flight  displays. Also used for vertical speeds and many other value  displays such as power settings and powerplant speeds. TAWS.  See terrain awareness and warning system. TCAS.  See Traffic Alert and Collision Avoidance System. Topographical database.  A volume of information stored  in an advanced cockpit system that details the topographical  features of the earth’s surface. Used by several systems  to assess aircraft position and altitude with respect to  surrounding terrain. Terminal Arrival Area.  The published or assigned track  by which aircraft are transitioned from the en route structure  to the terminal area. A terminal arrival area consists of a  designated volume of airspace designed to allow aircraft  to enter a protected area with obstacle clearance and signal  reception guaranteed where the initial approach course is  intercepted. Traffic Advisory (TA).  A warning issued by a traffic system  that alerts the pilot to other aircraft that have moved within a  prescribed “safety zone” that surrounds the aircraft. Terminal mode. One name used for the FMS/RNAV  sensitivity mode in which the aircraft is operating within 30  NM of an airport. In terminal mode, the required navigation  performance sensitivity of the course deviation indicator  becomes 1 NM. Also called approach arm mode. Traffic Alert and Collision Avoidance System.  An onboard  system that detects the presence of some aircraft operating  in the vicinity of the airplane by querying the transponders  of nearby aircraft and presenting their locations and relative  altitudes on a display. Alerts and warnings are issued when  nearby aircraft are deemed to be a threat to safety. Traffic  advisory systems such as ADS‑B are an offshoot of newer  technologies, but do not yet offer the reliability or accuracy  of proven, certified TCAS units. Terrain and obstacle database. An electronic database  storing details of the significant terrain features and obstacles  that could potentially pose a threat to aircraft flight. Some  obstructions, especially manmade, may not be in the database,  even if it is current. Do not plan a flight based on dependence  on the database to keep the aircraft clear of obstacles and  obstructions to navigation. Traffic data system.  An advanced avionics system designed  to aid the pilot in visually acquiring and maintaining  awareness of nearby aircraft that pose potential collision  threats. Traffic display. A pictorial display showing any aircraft  operating in the vicinity that have been detected by a traffic  data system. Terrain Awareness and Warning System (TAWS). An onboard system that can alert the pilot to a number of  potential hazards presented by proximate terrain such as  excessive rate of descent, excessive closure rate to terrain,  and altitude loss after takeoff. Traffic Information Service (TIS). A groundbased  advanced avionics traffic display system which receives  transmissions on locations of nearby aircraft from radar‑ equipped air traffic control facilities and provides alerts and  warnings to the pilot. Terrain display.  A pictorial display that shows surrounding  terrain and obstacles that present a potential threat to  your aircraft, given your present altitude. Draws terrain  information from a terrain and obstacle database. Turn anticipation. The function performed by FMS/ RNAV units to advise the pilot when to begin a turn to  the next waypoint in the programmed flight route to avoid  overshooting the programmed track. Terrain inhibit switch.  A switch that allows the pilot to  suppress all visual and auditory warnings given by a terrain  system. Often used to silence nuisance alerts when in  deliberate operation in the vicinity of terrain.  G-6