remarks section of the flight plan when requesting
tower en route control.
d. All approach controls in the system may not
operate up to the maximum TEC altitude of
10,000 feet. IFR flight may be planned to any
satellite airport in proximity to the major primary
airport via the same routing.
4-1-20. Transponder Operation
a. General
1. Pilots should be aware that proper application
of transponder operating procedures will provide
both VFR and IFR aircraft with a higher degree of
safety while operating on the ground and airborne.
Transponders with altitude reporting mode turned
ON (Mode C or S) substantially increase the
capability of surveillance systems to see an aircraft,
thus providing the Air Traffic Controller increased
situational awareness and the ability to identify
potential traffic conflicts. Even VFR pilots who are
not in contact with ATC will be afforded greater
protection from IFR aircraft and VFR aircraft which
are receiving traffic advisories. Nevertheless, pilots
should never relax their visual scanning for other
aircraft.
2. Air Traffic Control Radar Beacon System
(ATCRBS) is similar to and compatible with military
coded radar beacon equipment. Civil Mode A is
identical to military Mode 3.
3. Transponder and ADS-B operations on the
ground. Civil and military aircraft should operate
with the transponder in the altitude reporting mode
(consult the aircraft"s flight manual to determine the
specific transponder position to enable altitude
reporting) and ADS-B Out transmissions enabled (if
equipped) at all airports, any time the aircraft is
positioned on any portion of an airport movement
area. This includes all defined taxiways and runways.
Pilots must pay particular attention to ATIS and
airport diagram notations, General Notes (included
on airport charts), and comply with directions
pertaining to transponder and ADS-B usage.
Generally, these directions are:
(a) Departures. Select the transponder mode
which allows altitude reporting and enable ADS-B (if
equipped) during pushback or taxi-out from parking
spot. Select TA or TA/RA (if equipped with TCAS)
when taking the active runway.

Services Available to Pilots

(b) Arrivals. Maintain transponder to the
altitude reporting mode or if TCAS-equipped (TA or
TA/RA), select the transponder to altitude reporting
mode. Maintain ADS-B Out transmissions (if
equipped) after clearing the active runway. Select
STBY or OFF for transponder and ADS-B (if
equipped) upon arriving at the aircraft"s parking spot
or gate.
4. Transponder and ADS-B Operations in
the Air. EACH PILOT OPERATING AN AIRCRAFT EQUIPPED WITH AN OPERABLE ATC
TRANSPONDER, MAINTAINED IN ACCORDANCE WITH 14 CFR SECTION 91.413 OR
ADS-B TRANSMITTER, MUST OPERATE THE
TRANSPONDER/TRANSMITTER, INCLUDING
MODE C/S IF INSTALLED, ON THE APPROPRIATE MODE 3/A CODE OR AS ASSIGNED BY
ATC. EACH PERSON OPERATING AN AIRCRAFT EQUIPPED WITH ADS-B OUT MUST
OPERATE THIS EQUIPMENT IN THE TRANSMIT MODE AT ALL TIMES WHILE AIRBORNE
UNLESS OTHERWISE REQUESTED BY ATC.
5. A pilot on an IFR flight who elects to cancel
the IFR flight plan prior to reaching destination,
should adjust the transponder according to VFR
operations.
6. If entering a U.S. OFFSHORE AIRSPACE
AREA from outside the U.S., the pilot should advise
on first radio contact with a U.S. radar ATC facility
that such equipment is available by adding
"transponder" to the aircraft identification.
7. It should be noted by all users of ATC
transponders and ADS-B Out systems that the
surveillance coverage they can expect is limited to
"line of sight" with ground radar and ADS-B radio
sites. Low altitude or aircraft antenna shielding by the
aircraft itself may result in reduced range or loss of
aircraft contact. Surveillance coverage can be
improved by climbing to a higher altitude.
NOTE-
Pilots of aircraft equipped with ADS-B should refer to
AIM, Automatic Dependent Surveillance - Broadcast
Services, Paragraph 4-5-7 , for a complete description of
operating limitations and procedures.

b. Transponder Code Designation
1. For ATC to utilize one or a combination of the
4096 discrete codes FOUR DIGIT CODE DESIGNATION will be used; for example, code 2100 will
be expressed as TWO ONE ZERO ZERO. Due to the

4-1-15