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IFD540 Review

by JayBee

In August this year, Avidyne finally released it’s IFD540 GPS Navigator. The
device was initially announced in at Oshkosh 2011 for shipment the following
year. Its specs were impressive: Large, high-resolution touch display, full
FMS functionality including quick airways entry and altitude restrictions. Full
touch and button control. Slide in replacement for the GNS530W with connections
to the exact same avionics were to be supported.

The introductory offer seemed too good to be true: In exchange for a deposit
of $8500, a 50% discount on list price, one could get a unit as soon as they
were certified. Moreover the IFD540 was a slide in replacement of the Garmin
GNS530W and 4 hours of installation were included. As GNS530Ws sold for over
$8500 at the time, Avidyne was offering an upgrade to a vastly superior product
effectively free of charge. The deposit would be refundable up to the date of
certification. All aircraft on the GNS530W’s FAA STC-AML would be supported.

I decided to go for it and was one of the first few buyers of the device. I
saw a prototype in Friedrichshafen the following year and I was not disappointed.
The software was snappy and seemed nearly feature complete. However certification
slipped into early 2013. Then into late 2013, Q1/14 and finally into the summer
of 2014. Avidyne did a good job of communicating the project’s status on their
discussion board and as their progress seemed slow but steady I resisted the
urge to get my money back. My device finally arrived in October 2014. It was
installed in my Mooney a week later and I have now made five flights with it,
3 IFR and 2 VFR. I’ve had a number of requests to publish a review of it – so
here it goes:

Features

The device has a feature set that surpasses any other GA GPS Communicator on
the market. It is basically a GPS/NAV/COM, FMS and MFD in one.

WAAS and non-WAAS GPS navigation
VHF radio nav/com (10W with 16W variant due out)
5.7 Inch 640×480 pixel full colour multi-touch display
Moving map with drag-to-pan, pinch-to-zoom, flight plan ‘rubber-banding’ and
map information pop-up boxes when you touch map items
FMS-type flight planning including quick airways route entry, ad-hoc holds,
instrument procedures, altitude restrictions and ability to view route on map
as it is being entered
Terrain awareness and Forward-looking terrain alerting features (subset of TAWS
functionality)
Weather datalink (US airspace) and lightning sensor depiction
Traffic depiction
Geo-referenced ChartView Jepp approach plates
Electronic Checklist

Moreover on certification Avidyne announced the IFD540 has Bluetooth and Wifi
hardware built in that will be enabled in a future software release. A smaller
IFD440 that is plug-in compatible with the 430W is announced but not yet available.

Approvals

The IFD540 is FAA certified and Avidyne have an STC with an AML covering all
popular fixed wing GA aircraft. EASA certification is in progress. The AFM supplement
authorizes GPS/SBAS TSO-C146c Class 3 operation, for IFR enroute, terminal,
non-precision and precision approach procedures, including approaches with and
without vertical guidance. It complies with AC 90-105 and meets requirements
for RNP terminal departure and arrival procedures and RNP approach procedures
without RF (radius to fix) legs. It complies with AC 90-100A for RNAV 1 and
RNAV 2 procedures and requirements for RNP-10 and RNP-4 without time limitations.
It also complies with TSO requirements for VOR, ILS, glideslope, VHF comm, traffic,
weather, moving maps and fuel flow.

Installation

My installation was a replacement of a Garmin GNS530W and it took about 30
minutes. The installer made pictures of the settings screens of the GNS530W,
removed the GNS530W, slid the IFD540 into the same rack, switched it on and
entered the configuration information in near identical screens. We then tested
GPS reception, VOR reception and COM transmission/reception and that was it.
Installations that do not replace a GNS530W may require a lot more work installing
a WAAS antenna, doing wiring, installing a rack etc.

The IFD540 is pin compatible with the GNS530W so no wiring changes are necessary.
Avidyne do offer a couple of connections that the GNS530W doesn’t which you
can choose to wire up. I haven’t done that yet as any wiring work in the tight
Mooney is big job and best combined with other avionics updates. These new connections
include audio terrain call-outs to the audio panel, a frequency swap yoke switch
and monitoring of the standby COM frequency to the audio panel (not yet released
in the current software).

As the IFD540 was replacing a fully approved GNS530W installation, FAA paperwork
only involved a simple A&P logbook sign-off. No weight & balance change
is required.

In my aircraft the IFD540 is wired to an Aspen Pro PFD with ACU2, an S-TEC
55x autopilot, KN-62A DME, Skywatch-497 TAS, WX-500 stormscope, a blind encoder
and a PS Engineering audio panel and all connections work well. The IFD540 interfaces
to all the external devices the GNS530W works with.

Databases

The IFD540 requires a Navdata database from Jeppesen and Jeppesen also sell
terrain and obstacle data and ChartView IFR plates. The Navdata only is similarly
priced to the GNS530W subscription but can be used on an unlimited number of
Avidyne avionics in the same aircraft. Central Europe coverage costs €409
incl. VAT. A discounted bundle with all subscriptions is available and costs
€1789 per annum for Central Europe. Data is transferred to the IFD540 on
the ground using a USB key that goes into a port on the front of the bezel that
is removed after the data has been updated. Databases updates take a few minutes
– a little long for my taste given the throughput of USB and the limited amount
of data involved. Usefully, the USB port can also be used to charge phones and
tablets including iPads in flight.

User interface

The IFD540’s user interface is based on Avidyne’s R9 software for the Entegra
glass cockpit. As with all these things it requires some getting used to but
I have found it efficient and intuitive. Many functions can be done with the
touch screen as well as with buttons. Depending on the function either touch
or button pressing is usually faster. I find myself using touch mostly for text
entry Almost all functions are 1 or 2 presses away and there are no ‘deep’ menus


The device has three ‘Page Function Keys’ at the bottom of the screen. These
are ‘FMS’, ‘MAP’ and ‘AUX’. Each page has several tabs and the keys are rocker
switches so they can be used to flip back and forth between the tabs. FMS includes
all flight planning functionality, MAP covers the moving maps and Jepp charts,
AUX contains alerts, settings and utilities. The three keys represent the IFD540’s
‘menu structure’ and are used to control the devices.

On the bottom left of the bezel there are four ‘Line Select Keys’. These are
soft keys that are associated with context sensitive labels on the display.
On various screens of the UI they offer options, often hooks into the FMS you
are most likely to be looking for such as ‘skip hold’, ‘enable missed’ and ‘activate
approach’. In practice I have found them to be hugely useful and intuitive in
flight. I understand this is one of the concepts borrowed from FMS systems in
big jets.

On the right side of the device there are a number of ‘hard key’ shortcuts
to important functions also found on the GNS530W: Direct-to, Select Procedure,
Nearest, Frequency lists, Enter and Clear. Information called up from them slides
out from the right side of the display.

Data entry can be done with the double rotary button the bottom right of the
device, as with the 530W, but also using an on-screen keyboard. This keyboard
works surprisingly well. Regardless of the method used a feature called ‘Geofill’
will try to predict what you are trying to enter based on geographic proximity
so its rarely necessary to enter more than two letters. If, unlike me, you have
two IFD’s a keyboard will pop up on the #2 device for entering text on the #1
device.

When in map mode, the device uses so called ‘splits’, data strips that slide
out from the right side to about 1/4th of the display width and contain lists
of items (NRST and FREQ), flight plan waypoints or ‘data blocks’ that contain
useful information. These ‘splits’ can be revealed and hidden both by touching
a small tab at the side of the display or by pressing and holding a rocker switch
at the bottom


Customisation

The display can be highly customized with so-called data blocks, elements of
information you can choose to display on the left side or top of the display,
or in the data block ‘split’ on the moving map display. Frequencies for COM
and NAV as well as a traffic thumbnail go on the left, other data can be displayed
everywhere. The frequency list can also be highly customized, offering the ‘traditional’
2COM/2NAV but also 3, 4 or 5 COM frequencies. I played a round a lot with these
options but settled for 3 COM frequencies, navigation mode (eg TERM) and the
traffic thumbnail on the left, MSA on the top and ‘Next waypoint information’,
‘Destination Along Track Information’, ‘ETA at destination’, ‘Wind Vector’,
‘UTC Time’ and ‘Fuel Time Remaining’ which tells me everything I need to know
in flight.

As with the Garmin device levels of detail on the moving map can be adjusted
and the map can be de-cluttered when looking at it with soft keys.

Modes

Like other devices the IFD540 can output GPS, VLOC and OBS to a CDI/HSI and
an autopilot. It auto-sequences from GPS to VLOC and from OBS to VLOC during
an approach although on a particularly tightly vectored approach it once didn’t
in my case. In the US these don’t happen as often as they do here in Europe.

Radio use

The IFD540 ‘sounds’ slightly different from my GNS530W when I transmit. There
seems to be less filtering of background noise. When you tune a frequency, it
looks up and displays the station’s name, reducing scope for incorrect frequency
entry. NAV frequencies are tuned automatically enroute

Flight plan entry

To me the FMS feature is the best thing about this device. It is easy to use,
full featured and notifies the pilot when there is room for error


You enter flight plans starting from a pre-filled airport of origin. You then
either add a waypoint or a departure. After that another waypoint or an airway
from your waypoint, followed by the airway exit, another airway etc until you
get to the destination after which you can add arrivals and approaches. You
can enter an ‘ad-hoc’ hold at any waypoint in the flight plan and modify its
turn direction and length. Waypoints can be typed on the on-screen keyboard
or you can use rotary switches much like on the GNS530W. The device tries to
prefill the entire waypoint name based on a proximity search so its highly unlikely
you’ll need to enter more than 2 characters before the correct waypoint shows
up

 

The flight plan can have multiple airports, each with their own arrivals and
approaches, which is useful for training flights. However unfortunately only
the airport of origin can have a departure procedure. You can set target altitudes
in the flight plan for any waypoint. For waypoints that are part of a published
procedure target altitudes are pre-set when appropriate. A top-of-descent marker
is shown on the moving map and a TOD chime sounds when its time to go down.

Moving map

The IFD540’s display is significantly larger, sharper and more colourful than
that of the GNS530W it replaced. However given that we have all become used
to brilliant displays in iPads and smartphones, one gets used to this easily.
It does mean that the moving map is significantly more useful; really ‘MFD grade’
on this device. In fact I don’t know why anyone would buy an MFD alongside an
IFD540, much better to buy a second IFD540 and have all of the extra redundancy
for the same price. You can use fingers to pan and zoom the map. The map can
be set to track up, route up or North up with 360 deg and 240 deg views. If
you click any items on the map an information box pops. The map shows terrain,
including terrain coloured yellow or red as warnings, obstacles, including their
elevation, also coloured and enlarged for warnings, airports, navaids, airspace
(including class A), airways, intersections and of course the route. All route
segments except the active segment can be ‘rubber-banded’ to include another
waypoint. The segment that will be activated next is highlighted with white/magenta
stripes, especially useful when approaching a hold. There is also a ring for
IFR reserves and total fuel range if the device is connected to a totaliser.
The IFD can display traffic from a TAS, TCAS, TIS or ADS-B system and lightning
from a WX-500 or the equivalent Avidyne device. It supports airborne weather
from XM/ADS-B weather products (US airspace only) but bizarrely not yet from
Avidyne’s own global MLX770 Iridium satellite based weather system.

The terrain feature is quite good although difficult to explain in words. Essentially
they have implemented two of the features that are also part of certified TAWS
devices: GPS altitude based Terrain Awareness (TA) and Forward-Looking Terrain
Alerting (FLTA). TA is similar to the terrain feature on the GNS530W and the
GTN750. It highlights terrain and obstacles in a circle around your position
either cyan, yellow or red depending on the threat level and emphasises such
obstacles by drawing a bubble around them. FLTA projects where you are going
and predicts an imminent terrain impact. Its is shown as a ‘flashlight beam’
in front of the aircraft on the moving map and is disabled in a rectangle around
airports to avoid false alerts.

Comparison

Here is a spec comparison of the IFD540 and the Garmin GNS530W and GTN750:


IFR flight experience

I have now made a small number of airways flights with the IFD540 and flown
ILS, VOR, LNAV/VNAV and LPV approaches with it. My aircraft has an Aspen PFD
and an S-TEC 55x autopilot and I have flown SIDs, enroute, holds, STARs and
approaches coupled to the autopilot.

In general I really like the device. Notably, flight plan entry is many times
easier and less error-prone. The map display is so good I find myself looking
a lot less at my portable Garmin 695 and SkyDemon on the iPad. The ‘Line Select
Keys’ seem to always know what I am thinking.

New flight plans need to be activated after you enter them which is something
I have to get used to as that was not the case on the 530W.

Alerts are plentiful (airspace ahead) and show up both on the page you are
looking at (where you can clear them away) as well as in a ‘Alerts’ tab in the
AUX Page. The AUX page select key turns cyan, yellow or red depending on the
level of the highest importance alert active. All a little ‘in your face’ to
my taste but I guess that is the point of alerts.

The autopilot flew all segments as well as it did with my GNS530W including
holds, curved flight paths as well as ILS, VOR and GPS approaches with and without
glideslope. As GPS approaches go, the IFD supports LNAV, LNAV+V, LNAV/VNAV,
LPV and LP approaches.

Reliability

So far I have stayed mostly in VMC to get used to the new user interface and
that was a good decision as there are also still some bugs to iron out. My device
doesn’t seem to receive EGNOS signals so my LPV approach was downgraded to LNAV
only.

I lost my GPS fix entirely on the first RNAV approach I flew, around 700 ft
so I had to go missed. It was good practice but not much fun when it happened.

Avidyne have since confirmed EGNOS doesn’t work in the firmware the IFD540
was shipped with due to a mistake in testing. The loss of GPS fix is also a
known bug. Eight service letters have been published in the last few weeks with
various such defects that need to be fixed. Avidyne has now issued firmware
update v10.0.2.0 that claims to fix these eight issues, including the loss of
GPS fix I experienced. EGNOS will work only when they release their second update
v10.0.3.0 scheduled for December. Also, my device has already been recalled
for a hardware change.

The view I take on this is that the IFD540 was a highly ambitious project that
delivered a product I consider superior to anything else out there. As a very
early user, probably Europe’s first, I accept some issues as long as Avidyne’s
response is open, effective and swift. In my view, it is.

However, all of this does make one wonder how effective certification really
is.


Page last edited 10th December 2014