AIM
4/3/14
4−5−18
Surveillance Systems
(b)
The ADS−B−to−radar association pro-
cess within the ground system may at times have
difficulty correlating an ADS−B report with
corresponding radar returns from the same aircraft.
When this happens the pilot may see duplicate traffic
symbols (i.e., “TIS−B shadows”) on the cockpit
display.
(c)
Updates of TIS−B traffic reports will
occur less often than ADS−B traffic updates. TIS−B
position updates will occur approximately once
every 3−13 seconds depending on the type of radar
system in use within the coverage area. In
comparison, the update rate for ADS−B is nominally
once per second.
(d)
The TIS−B system only uplinks data
pertaining to transponder−equipped aircraft. Aircraft
without a transponder will not be displayed as TIS−B
traffic.
(e)
There is no indication provided when any
aircraft is operating inside or outside the TIS−B
service volume, therefore it is difficult to know if one
is receiving uplinked TIS−B traffic information.
3.
Pilots and operators are reminded that the
airborne equipment that displays TIS−B targets is for
pilot situational awareness only and is not approved
as a collision avoidance tool. Unless there is an
imminent emergency requiring immediate action,
any deviation from an air traffic control clearance in
response to perceived converging traffic appearing
on a TIS−B display must be approved by the
controlling ATC facility before commencing the
maneuver, except as permitted under certain
conditions in 14CFR §91.123. Uncoordinated
deviations may place an aircraft in close proximity to
other aircraft under ATC control not seen on the
airborne equipment and may result in a pilot
deviation or other incident.
d. Reports of TIS
−B Malfunctions
Users of TIS−B can provide valuable assistance in the
correction of malfunctions by reporting instances of
undesirable system performance. Reporters should
identify the time of observation, location, type and
identity of the aircraft, and describe the condition
observed; the type of avionics system and its software
version used. Since TIS−B performance is monitored
by maintenance personnel rather than ATC, it is
suggested that malfunctions be reported in anyone of
the following ways:
1.
By radio or telephone to the nearest Flight
Service Station (FSS) facility.
2.
By FAA Form 8740−5, Safety Improvement
Report, a postage−paid card is designed for this
purpose. These cards may be obtained from FAA
FSSs, Flight Standards District Offices, and general
aviation fixed−based operators.
3.
By reporting the failure directly to the FAA
Surveillance and Broadcast Services Program Office
at 1−877−FLYADSB or http://www.adsb.gov.
4
−
5
−
9. Flight Information Service
−
Broadcast (FIS
−
B)
a.
FIS−B is a ground broadcast service provided
through the ADS−B Services network over the
978 MHz UAT data link. The FAA FIS−B system
provides pilots and flight crews of properly equipped
aircraft with a cockpit display of certain aviation
weather and aeronautical information. FIS−B service
availability is expected across the NAS in 2013 and
is currently available within certain regions.
b.
The weather products provided by FIS−B are
for information only. Therefore, these products do
not meet the safety and regulatory requirements of
official weather products. The weather products
displayed on FIS−B should not be used as primary
weather products, i.e., aviation weather to meet
operational and safety requirements. Official
weather products (primary products) can be obtained
from a variety of sources including ATC, FSSs, and,
if applicable, AOCC VHF/HF voice, which can
transmit aviation weather, NOTAMS, and other
operational aeronautical information to aircraft in
flight. FIS−B augments the traditional ATC/FSS/
AOCC services by providing additional information
and, for some products, offers the advantage of being
displayed graphically. By using FIS−B for orientation
and information, the usefulness of information
received from official sources may be enhanced, but
the user should be alert and understand any
limitations associated with individual products.
FIS−B provides the initial basic products listed below
at no−charge to the user. Additional products are
envisioned, but may incur subscription charges to the
user. FIS−B reception is line−of−sight within the
service volume of the ground infrastructure.