REFERENCE-
AIM, Para 5-3-2, Position Reporting.

3. At times controllers will ask pilots to verify that they are at a particular altitude. The phraseology used
will be: "VERIFY AT (altitude)." In climbing or descending situations, controllers may ask pilots to "VERIFY
ASSIGNED ALTITUDE AS (altitude)." Pilots should confirm that they are at the altitude stated by the controller
or that the assigned altitude is correct as stated. If this is not the case, they should inform the controller of the
actual altitude being maintained or the different assigned altitude.
CAUTION-
Pilots should not take action to change their actual altitude or different assigned altitude to the altitude stated in the
controllers verification request unless the controller specifically authorizes a change.

c. ARTCC Radio Frequency Outage. ARTCCs normally have at least one back-up radio receiver and
transmitter system for each frequency, which can usually be placed into service quickly with little or no
disruption of ATC service. Occasionally, technical problems may cause a delay but switchover seldom takes
more than 60 seconds. When it appears that the outage will not be quickly remedied, the ARTCC will usually
request a nearby aircraft, if there is one, to switch to the affected frequency to broadcast communications
instructions. It is important, therefore, that the pilot wait at least 1 minute before deciding that the ARTCC has
actually experienced a radio frequency failure. When such an outage does occur, the pilot should, if workload
and equipment capability permit, maintain a listening watch on the affected frequency while attempting to
comply with the following recommended communications procedures:
1. If two-way communications cannot be established with the ARTCC after changing frequencies, a pilot
should attempt to recontact the transferring controller for the assignment of an alternative frequency or other
instructions.
2. When an ARTCC radio frequency failure occurs after two-way communications have been established,
the pilot should attempt to reestablish contact with the center on any other known ARTCC frequency, preferably
that of the next responsible sector when practicable, and ask for instructions. However, when the next normal
frequency change along the route is known to involve another ATC facility, the pilot should contact that facility,
if feasible, for instructions. If communications cannot be reestablished by either method, the pilot is expected
to request communications instructions from the FSS appropriate to the route of flight.
NOTE-
The exchange of information between an aircraft and an ARTCC through an FSS is quicker than relay via company radio
because the FSS has direct interphone lines to the responsible ARTCC sector. Accordingly, when circumstances dictate a
choice between the two, during an ARTCC frequency outage, relay via FSS radio is recommended.

d. Oakland Oceanic FIR. The use of CPDLC and ADS-C in the Oakland Oceanic FIR (KZAK) is only
permitted by Inmarsat and Iridium customers. All other forms of data link connectivity are not authorized. Users
must ensure that the proper data link code is filed in Item 10a of the ICAO FPL in order to indicate which satellite
medium(s) the aircraft is equipped with. The identifier for Inmarsat is J5 and the identifier for Iridium is J7. If
J5 or J7 is not included in the ICAO FPL, then the LOGON will be rejected by KZAK and the aircraft will not
be able to connect.
e. New York Oceanic FIR. The use of CPDLC and ADS-C in the New York Oceanic FIR (KZWY) is only
permitted by Inmarsat and Iridium customers. All other forms of data link connectivity are not authorized. Users
must ensure that the proper data link code is filed in Item 10a of the ICAO FPL in order to indicate which satellite
medium(s) the aircraft is equipped with. The identifier for Inmarsat is J5 and the identifier for Iridium is J7. If
J5 or J7 is not included in the ICAO FPL, then the LOGON will be rejected by KZWY and the aircraft will not
be able to connect.
5-3-2. Position Reporting
The safety and effectiveness of traffic control depends to a large extent on accurate position reporting. In order
to provide the proper separation and expedite aircraft movements, ATC must be able to make accurate estimates
of the progress of every aircraft operating on an IFR flight plan.

En Route Procedures

5-3-13