Section 3. Displays
Verification of the accuracy of new or modified digital maps must be accomplished through the use of “targets of opportunity” over displayed fixes, navigational aids, etc. Any observed discrepancies must be documented to indicate the observed direction and displacement. If any errors cannot be corrected or if a facility is otherwise dissatisfied with the results from “targets of opportunity,” a request may be made through the FICO for a flight inspection. If no discrepancies are noted, no documentation is required.
Facilities operating in the narrowband mode must ensure that, as a minimum, radar target symbols, aircraft identifications (ACIDs), and altitude information are displayed at all sectors affected by altitude assignments involving more than one altitude (Block Altitude) when radar separation is being provided.
The display of Mode C targets and limited data blocks is necessary for application of Merging Target Procedures. Sectors must ensure the display of Mode C targets and data blocks by entering appropriate altitude limits and display filters to include, as a minimum, the altitude stratum of the sector plus:
- 1,200 feet above the highest and below the lowest altitude or flight level of the sector where 1,000 feet vertical separation is applicable; and
- 2,200 feet above the highest and below the lowest flight level of the sector where 2,000 feet vertical separation is applicable.
- The data block, for purposes of this paragraph, must contain the beacon code and mode C altitude at a minimum.
- Exception to these requirements may be authorized for specific altitudes in certain ARTCC sectors if defined in appropriate facility directives and approved by the respective service area operations directorate.
Facilities operating in the narrowband mode must ensure that sector controllers are immediately briefed on any change in the status of the Weather Fixed Map Unit (WFMU) or radar polarization.