Interim Guidance for UAT Avionics Operating with Safe Flight 21 ...

Note: The topic of TIS-B service status indication is expected to be further refined
in the next update to [TIS-B MASPS]. It is possible that when published, the
standards may differ somewhat from the preliminary information presented
in this section.
4.2 Consideration for Processing and Display of FIS-B Products
Guidance applicable to the processing and display of uplinked FIS-B products is provided
in Section 3.8.1 of [FIS-B MASPS].
One additional set of guidance beyond [FIS-B MASPS section 3.8.1] is applicable to the
NEXRAD Graphics Product discussed in Section 2.3.3.2. If the cockpit display of the
NEXRAD Graphics product is updated in an incremental fashion, the following guidelines
apply (i.e., as APDUs with new data (later observation time or cut-off time) are received,
they are integrated directly into the cockpit display, replacing that incremental portion of
the display contained in that APDU):
� The product time displayed shall be the time of the oldest source product (mosaic
or individual observation) that contributes to the displayed image.
� The time span between the oldest and newest source product contributing to the
displayed image shall not exceed 10 minutes. Portions of the image that exceed
this 10 minute requirement shall be depicted as missing data.
� This incremental display technique should not be used as the basis for a
Sequential or Looping Product.
Note: This guidance seeks to limit the maximum age difference of the data
contained in these displays. This guidance will be included in the next
update to [FIS-B MASPS].
29