Technical data

Product Specification
HIF-2121/R5 CAGE CODE: 97896 SCALE: NONE SIZE: A DWG NO: 965-1176-601 REV: D SHEET 110
6.10.2.3.2 Windshear Monitor (MKVIII EGPWS)
The Windshear monitor is activated by failures that affect the Windshear function. Both analog and digital versions of the
monitor are provided. The configured discrete output is biased on with loss of system power.
6.10.2.3.3 Terrain Awareness Monitor
The Terrain Awareness monitor is encoded on an ARINC 429 label and is supplied by the Terrain Awareness function.
6.10.2.3.4 Terrain Not Available Monitor
The terrain not available monitor is encoded on an ARINC 429 label and is supplied by the Terrain Awareness function.
6.10.2.3.5 Envelope Modulation Inop
If any of the needed input data to the Envelope Modulation functionality is not available, the Envelope Modulation INOP is
set.
6.10.2.3.6 Terrain Clearance Inop
Terrain Clearance Floor (TCF) INOP is encoded on an ARINC 429 label when any of the needed inputs for terrain clearance
are not available.
6.10.2.3.7 Callout Inop
The callout INOP is encoded on an ARINC 429 label whenever an undefined callout menu is selected or if the needed altitude
input is faulted.
6.10.2.3.8 Bank Angle Inop
The bank angle INOP is encoded on an ARINC 429 label if either the roll angle or radio altitude inputs are faulted.
6.10.3 LRU Flight history Recording
Flight history in the EGPWS is divided into the following categories: fault history, INOP history, ground history, warning
history, status history and cumulative counters. These categories are provided for the recording of faults, alerts and other
statistical information required for maintenance of the EGPWS.
6.10.3.1 Fault History
Fault history is stored in non-volatile memory in the form of fault history records. Fault history records contain information
that will allow operators to find specific information about faults that occurred during EGPWS operation. Fault history
information can be reviewed through the use of the voice output, RS-232 test interface, or uploaded through the PCMCIA
interface for later review.
Fault recording is not enabled until at least 25 seconds have elapsed since power up or when on the ATP bench tester.
For multiple occurrences of the same fault in any, one flight leg, only one fault record will be stored.
When the “In Air” status is false, only internal faults are stored. When the “In Air” status is true, both internal faults and
external faults are stored. The system is capable of storing a minimum of 256 fault history records and 64 fault legs in non-
volatile memory. The required number of faults (256) implies a capability to store an average of 4 faults per leg.
The self-test switch in the cockpit activates the audio fault history readout. Fault history can also be accessed with a PC via
the front panel test connector.
6.10.3.2 Fault Statistics
Two forms of fault statistics are maintained: Cumulative counters and INOP history records. Cumulative counters can be
used to gather long term statistical data on certain EGPWS parameters. INOP history records can be used to identify specific
instances of certain INOP situations for analysis after the fact, to identify causes of these situations. Cumulative counters are
intended for internal use and are only available through the RS-232 and PCMCIA interfaces. INOP history information can
be reviewed through the use of the voice output, RS-232 interface, or uploaded through the PCMCIA interface for later
review.