Books & Gear
A first look at the Skyecho II
uavionix Skyecho II low-cost electronic conspicuity device test, part one
I have been following the series of articles on Electronic Conspicuity in
Pilot magazine with great interest since becoming a convert to the idea of ‘an extra set of electronic eyes’. Specifically since some friends were involved in a mid-air collision – two white gliders skirting cloud base. Fortunately all three survived, but both aircraft were written off and two of the pilots had an impromtu self-taught parachuting lesson.
I did not ground-test the unit in Transmit/receive mode, since my house is within the circuit of an active major airport, and did not want to create any false traffic indications or alarms.
For a traffic display you will need Skydemon, easyvfr or some other compatible app. Having told Skydemon how to connect, it took seconds to start the ‘conversation’. EASYVFR took a little longer, since I had to seek advice from the software maker, but once the settings were correct, again it worked instantly. EASYVFR can also use the GPS source from the Skyecho II, saving the battery of your phone or tablet. Skyecho is ideal for those devices which don’t have internal GPS – and it has a ‘SIL 1’ GPS, so the CAA are happy with its output being used for ATC purposes (per CAP 1391) ie to feed GPS data to any ADS-B Out device.
There are no visual alerts from the Skyecho itself, so what you see depends on your moving map. The interface can handle audio alerts but either it is not implemented in Skyecho, or in my displays – I heard nothing. (Skydemon are thinking about this.) Audio alerts would reduce the need for heads-down fixation on displays.
The biggest challenge in a flight test is knowing where other ADS-B equipped aircraft may be. No aircraft at my home base have it fitted, although my chariot is pre-wired, its GPS source is not Sil-anything so cannot be connected to the transponder. My home, however, is on the base leg for Instrument approaches to R16 at ’ABZ, so I used Skyecho to track ADS-B aircraft, comparing both visually and via Flightradar 24 (FR24) or equivalent. As I write, I am regularly tracking helicopters out to twenty miles, and airliners out to 158nm. The maximum range is hopefully irrelevant to collision avoidance, but it demonstrates the sensitivity of the receiver, which may partially compensate for
the non-optimum position of the Skyecho in the cockpit, where the wings, engine and fuselage may block or attenuate signals.
I noted also that the odd aircraft whose data on FR24 implied they had ADS-B was not displayed via Skyecho when apparently in coverage. Since I do not know how FR24 actually gets all its data, I leave this as a comment and not a criticism.
Designed to be easily transferable between aircraft (indeed it will fit any shirt pocket-although the manual warns against that when transmitting!) Skyecho can have the ICAO code for the host aircraft and other configuration data updated from your browser in a few seconds. For non-registered aircraft, such as drones, parachutes, etc, I am assured there are procedures in place at CAA to provide the required ‘ICAO code’ free of charge.
There is one simple rule: Skyecho and the aircraft transponder (in Mode S) must not both transmit at the same time on any aircraft. This is also easily set via wifi or by the aircraft’s transponder control. The sample model I received did not yet have the Mode C-only traffic display capability, which will show the traffic and its pressure height but not bearing.
Fitting the Skyecho unit was dead easy, using the supplied RAM mount vacuum pad – all it needs is a smooth vertical surface with a decent external view. If you have to compromise the location, mount it forward, since collisions from behind are rare. If the slope of your windows causes a problem, you can disconnect the RAM mount (a 4mm Allen Key) and use a flexible Go Pro mount, so you can optimise both location and vertical orientation of the device.
I was amazed at the Receive mode tracking, with close intruders being tracked even behind me. This happened frequently. It may be due to strong local reflections, so a small shift in the receiver location could spoil this, so I cannot guarantee similar or consistent performance.
All traffic is shown by an aircraft symbol, and in some cases a symbol appropriate to the aircraft type – this is outside Skyecho and uavionix’s area of responsibility. The aircraft track length is proportional to groundspeed, also with a digital readout. Relative height between you and the intruder is shown, and an up/down arrow for intruder vertical speed. The display updates every second, which allows you to observe intruders turning towards or away from you, and their rate of turn. The intruder colour is red within approx 1,000 feet of ‘own ship’ height, within ten miles and becomes green as it climbs or turns away.
Skydemon was set to show my own aircraft in yellow and by default other traffic as white. The display only shows intruder ident, vector (at times) climb/descend arrow and relative altitude. For the same event, every time easyvfr showed a red alert, Skydemon did not. The Skydemon manual indicates the traffic symbols should turn red when in close proximity, but I did not see it. There needs to be standardisation of threat displays.
Skyecho has a nominal twelvehour battery life. In receive-only mode it ran for the best part of two days, overnight and then for twelve hours of my time spent flying and managing the airfield.
There are real-time weather maps being broadcast in the south of England, which Skyecho can receive and pass for display, but those transmissions do not stretch as far north as my base in Scotland.
Some aviation applications require internet access before use. You will therefore need to delve into your tablet settings until NOTAM, WX, etc are downloaded, only then disconnecting the live internet feed and then connect to the Skyecho wifi to get the traffic functionality. Several times I made the mistake of changing from one to the other before NOTAM downloading was complete on Skydemon, so it was change back and start again or resume.
Skyecho 2 works as advertised, giving good visual alerting to traffic which may be a threat. Showing intruders as threats when within 1,000 feet, even if ten miles away, on the easyvfr display is great when flying under IFR, but may be distracting in busy environments. If all close traffic is red, which one is the real priority? It may not be the closest.
By contast the alerts created by FLARM have significant intruder motion processing, and are optimised for gliders sharing thermals etc. False alarms are rare. I know from converting PPLS to gliders that these alert thresholds would be far to close for comfort, but there needs to be a happy medium between spurious alerts, which distract the pilot from looking out, and reduce confidence in the system, and an alert delivered too late.
Skyecho’s real-time weather and Mode C traffic displays have been demonstrated in UK, and when implemented nationwide, will only add to its value. Skyecho devices are already on the CAA ‘approved’ list for electronic conspicuity devices (CAP 1391) and it could save you the cost of an external GPS sensor.
Price of the device is currently just over £400. It can be bought alone, or with optional suction mounts, and matching cases.
ABOVE: the complete kit, including suction mount and USB cable comes in a zipper case
Screen shots show, from left, Skyecho's impressive range and easyvfr display of contacts (with vertical separation and speed) and red-coded alerts
the corresponding Sykdemon display – note that this app does not identify any of the contacts as posing a collision risk LEFT: