Document ID: chunk:federal_register_of_legislation:F2023C00696:body:0:p27
Version: federal_register_of_legislation:F2023C00696
Segment Type: other
Provision Reference: 
Character Range: 76293–79422

the situation display is different from that assigned to the aircraft, ATC must ask the pilot to re-enter the assigned aircraft identification.

10.2.2.3         If the identification of an aircraft as shown on the situation display is different from that assigned to the aircraft, and a request under subsection 10.2.2.2 has not resolved the discrepancy, ATC must ask the pilot to confirm that the correct aircraft identification has been selected.

10.2.2.4         If the discrepancy continues following confirmation by the pilot that the correct aircraft identification has been set on the ADS-B identification feature, ATC must:

(a)         tell the pilot of the persistent discrepancy; and

(b)         if possible, correct the label showing the aircraft identification on the situation display; and

(c)          tell the next control position and any other interested unit using ADS-B for identification purposes of the erroneous aircraft identification transmitted by the aircraft.

10.2.3              Verification of level information

10.2.3.1         The tolerance value for pressure altitude-derived level information displayed to the controller is ±200 ft. Geometric height information must not be used for separation.

10.2.3.2         ATC must verify displayed pressure altitude-derived level information:

(a)         on initial contact with an aircraft or, if this is not feasible, as soon as possible after initial contact; and

(b)         by simultaneous comparison with:

(i)            altimeter-derived level information received from the same aircraft by radiotelephony; or

(ii)          at an aerodrome — the aerodrome elevation during the take-off roll, if the level information subsequently indicates a positive climb after take-off.

10.2.3.3         If aircraft pressure altitude-derived level information is within the approved tolerance value, the pilot need not be advised of the verification. Geometric height information must not be used to determine if altitude differences exist.

10.2.3.4         If the displayed level information is not within the approved tolerance value or if a discrepancy greater than the approved tolerance value is detected after verification, ATC must tell the pilot of this and ask the pilot to check the pressure setting and confirm the aircraft's level.

10.2.3.5         If the discrepancy continues to exist after confirmation of the correct pressure setting, ATC must:

(a)         ask the pilot to stop Mode C or ADS-B altitude data transmission, if this does not cause the loss of position and identity information, and tell the next control position or ATC unit for the aircraft of the action taken; or

(b)         tell the pilot of the discrepancy and ask that the operation continue in order to prevent loss of position and identity information of the aircraft, if possible, override the label displayed level information with the reported level and tell the next control position or ATC unit for the aircraft of the action taken.

10.2.4              Determination of level occupancy using ATS surveillance system-derived level information

10.2.4.1