Avionics News September 2014 - 22

general aviation aircraft consist of a database, a processor
to crunch that data against the third component - a TSO
satellite-navigation receiver - yes, a GPS.
The cycle runs the same for anything dependent on upThis package depends on the GPS to know its location -
to-date data. And this is largely universal. Options for the
in minutes and seconds of latitude and longitude - its altidata source vary for some, not for others.
tude (satellite-referenced or ground observation-based) as
First up, and probably most common, comes the cuswell as your direction and speed of flight. By comparing
tomer's GPS - if it's an IFR installation, this is legal for
the aircraft's position, speed and altitude to the electronic
instrument flight. For VFR installations? The smart aviadatabase of terrain details - height, depth, the lakes, rivtor counts on the software being up-to-date and functional
ers, road and railroads - these baby ground-proximity deregardless of the flight plan filed,
vices can prompt as much warning as
VFR or IFR.
the pilot might need: several minutes.
Frequencies change, procedures
Neglect to update the ground-proxAS G E NE RA L
change, navigation stations go quiet.
imity database and you face the real
No aviator flies on out-of-date data
prospect of a new tower or building
AVIAT I O N A DV A NCE S
without running the risk of a change
that arises at an inconvenient location
BRO U G H T I N
leaving them in the dark - or worse.
and time.
RUD I M E NTA RY
This same imperative applies to
This is likewise for the EVS
MOV I NG -M A P G P S
portable devices pilots increasingly
system. Enhanced vision systems
NAV I G ATO R S ,
use in their cockpits: from hand-held
employ an infrared camera to see
MU LT I F U NCT I O N
GPS navigators to tablets employed
through the dark, the haze and nightas EFBs.
DIS P L AY S A ND
time obscuration - what you see is
what you get.
EVE R -M O R E
Ground proximity, terrain
SVS differs. Like a navigation daSOP H I S T I CAT E D
avoidance and SVS
tabase, SVS sees what it's told it can
PANE L E Q U I P M E NT,
Increasingly, pilots turn to glass,
see - what's in its brain.
DATA - D R I V E N
electronic flight-reference equipment
While on your short final, you
DEV I CE S B E CA M E
that depends on another device's
won't notice a white-tale deer crossTHE RU L E
software such as an IFR GPS helping
ing the runway because you respond
navigate the aircraft while the pilot
to visual cues to initiate a go-around.
watches an electronic, digital primary
SVS, like some ground-proximity
flight display.
warning systems, "sees" and "shows"
The GPS/PFD partnership depends
only what's in its database. In this
on up-to-date data in the GPS - but
way, it parallels ground-proximity
uses its own data to drive the PFD
warning systems that compare GPS
functions. Nonetheless, firmware updates should be downposition to the location of airports, navigational aids, rivloaded and installed as quickly as the original equipment
ers and roads in its database.
manufacturers seem to develop advances and improveLike the ground-warning gear, software for synthetic
ments on items such as a PFD.
vision systems follows the same need for periodic updates
Multifunction displays also require periodic software
- and a year is the common cycle.
updates to keep them functioning optimally and accurately
Garmin's cycle for these devices varies, according to
- much the same reasoning behind GPS-software updates.
Matt Harrah, director, aviation product support.
Periodically, PFD and MFD firmware need updating to
"Year over year is most common cycle for terrain, ungive them the benefits of advances in the factory-develless some anomalies on occasion may require an update,"
oped capabilities. Inconvenience and embarrassment is the
Harrah said.
highest-probability outcome from using out-of-date data.
Taxi and obstacles can happen on 56-day cycles. And
But out-of-date data puts the pilot and passengers at a
SVS data happens as Garmin continues to roll in improvereal risk when the software drives either a ground-proximiments in terrain detail and resolution of the imagery - all
ty system or a synthetic vision system display on the PFD.
made possible thanks to compression and decompression
The ground-proximity devices most common among
algorithms.
SOFTWARE MANAGEMENT
Continued from page 21

RAT H E R T H A N
T H E E X CE P T I O N.

avionics news

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2014

Avionics News September 2014

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