User's Manual

UL-801 Installation Manual
Page 105
23-20-06 15 December 2011
CSPs and between the UniLink and peripheral devices, datalink-based crew actions,
and other datalink events.
Non-TSO Functions
(1) Telephony Communication Interface - Ref: SRD
The telephony communication interface provides an alternate media for the limited
transfer of operator’s AOC messages and weather graphics between the aircraft and
the ground. The telephony interface uses industry standard protocols for access to an
airborne telephone modem that is part of an on-board satellite communication system.
Telephony messaging is supported through separate air-air/air-ground channels from
other SATCOM ACARS ATS and FANS 1/A+ message functions.
(2) FANS 1/A+ Ops Credit for FANS - Ref: DO-258A, GOLD, ARINC 622
UniLink system functionality is greatly enhanced by offering a FANS-1/A +
implementation, which is intended to improve safety of flight, enhance efficiency,
and increase capacity by replacing routine voice transmissions between flight crews
and ATC with datalink messages during flight in oceanic and remote areas that have
no or limited radar coverage. FANS operational credit can be applied for following
UniLink installation airworthiness approval for aircraft that are properly equipped.
(3) Weather Graphics - Ref: SRD
Graphical weather images can be requested by the crew and transferred by UniLink
from the ground via the Telephony Communication Interface and presented on
compatible display units (UASC only) in the cockpit. This facility is supported by
ground AOC facilities complying with UASC-proprietary protocols and message
formats. The images presented are intended for non-essential use.
2. Software Criticality
SCN 10.X Main UniLink Bootloader Software
Main UniLink Bootloader software version SCN 10.X is categorized as DO-178B Level D
(Minor). Level D software is defined by DO-178B as “software whose anomalous behavior,
as shown by the system safety assessment process, would cause or contribute to a failure of
system function resulting in a minor failure condition for the aircraft”.
VDR Bootloader SCN 10.X
The VDR boot software is partitioned from the VDR application and will be developed to
Level D. The VDR boot software is stored in a flash memory device separate from that of the
application software. Once the application software is invoked, the boot software is
deactivated.
VDR Transmit Monitor SCN 10.X
The VDR transmit monitor software is partitioned from the VDR boot and application
software and will be developed to Level C. The VDR transmit monitor software is stored and
executes on a separate microcontroller residing on a different physical circuit card from that
that hosts the VDR boot and application functions.