aim-274

AIM

4/20/23

−

Surveillance Systems

The following facilities have been projected to receive ASSC:

TBL 4

−

SFO

San Francisco International

CLE

Cleveland

−

Hopkins International

MCI

Kansas City International

CVG

Cincinnati/Northern Kentucky Intl

PDX

Portland International

MSY

Louis Armstrong New Orleans Intl

PIT

Pittsburgh International

ANC

Ted Stevens Anchorage International

ADW

Joint Base Andrews AFB

−

6. Traffic Information Service (TIS)

a. Introduction.

The Traffic Information Service (TIS) provides information to the cockpit via data link, that

is similar to VFR radar traffic advisories normally received over voice radio. Among the first FAA

−

provided data

services, TIS is intended to improve the safety and efficiency of “see and avoid” flight through an automatic
display that informs the pilot of nearby traffic and potential conflict situations. This traffic display is intended
to assist the pilot in visual acquisition of these aircraft. TIS employs an enhanced capability of the terminal Mode
S radar system, which contains the surveillance data, as well as the data link required to “uplink” this information
to suitably

−

equipped aircraft (known as a TIS “client”). TIS provides estimated position, altitude, altitude trend,

and ground track information for up to 8 intruder aircraft within 7 NM horizontally, +3,500 and

−

3,000 feet

vertically of the client aircraft (see FIG 4

−

5, TIS Proximity Coverage Volume). The range of a target reported

at a distance greater than 7 NM only indicates that this target will be a threat within 34 seconds and does not
display a precise distance. TIS will alert the pilot to aircraft (under surveillance of the Mode S radar) that are
estimated to be within 34 seconds of potential collision, regardless of distance or altitude. TIS surveillance data
is derived from the same radar used by ATC; this data is uplinked to the client aircraft on each radar scan
(nominally every 5 seconds).

b. Requirements.

In order to use TIS, the client and any intruder aircraft must be equipped with the appropriate cockpit

equipment and fly within the radar coverage of a Mode S radar capable of providing TIS. Typically, this will be
within 55 NM of the sites depicted in FIG 4

−

6, Terminal Mode S Radar Sites. ATC communication is not a

requirement to receive TIS, although it may be required by the particular airspace or flight operations in which
TIS is being used.

FIG 4

−

TIS Proximity Coverage Volume