TRAFFIC INFORMATION SERVICE (TIS)
This section applies only to TIS systems.
TIS is an alerting system (covered by US Pat. 6512975) that provides
visibility to nearby traffic enhancing "see and avoid" collision avoidance.
It's purpose is to increase situational awareness by supplying information
to assist in visually acquiring nearby aircraft. TIS does not relieve the
pilot of "see and avoid" responsibility. No avoidance maneuvers are pro-
vided or recommended by TIS.
The service is offered through the Federal Aviation Administration's
Mode S terminal sensors and uses the same surveillance information
provided to ATC. Estimated bearing, distance, altitude and heading
information for aircraft within 7 NM and +3,500/-3,000 feet altitude of
your aircraft is sent over the Mode S datalink to the TIS display. The
pilot is also alerted to aircraft that are predicted to be within 30 seconds
of a potential collision, no matter the distance or altitude.
KMD 550 w/ TIS Display
KT 73 Mode S
Target aircraft are displayed only if operating a Mode A, C or S
transponder. TIS operation is transparent to ATC and requires no con-
When the onboard TIS system makes a request for TIS, the request is
sent via the Mode S transponder through the datalink. The first available
Mode S sensor capable of supporting TIS for your aircraft responds by
sending data back through the datalink on every scan of the sensor
(approximately every 5 seconds). TIS will be provided by the sensor as
long as the aircraft is within coverage range of that sensor. When
entering the coverage range of another sensor, TIS will continue pro-
vided the next sensor is TIS capable. The transfer of service is auto-
matic. In addition to traffic data, the aircraft receives status messages
that advise the pilot when TIS service has been initiated, is continuing, or
has been terminated.
While coverage varies with terrain and local site parameters, "line-of-
sight" coverage is to be expected within 55 NM of a TIS capable Mode S
sensor. Terrain and obstacles can cause areas of no radar coverage.
Rev 3 Jun/2004
KMD 550/850 Traffic Addendum