Edited 15/06/2016 to take into account new developments since I originally wrote this article
I’ve been flying with Flyskyhy for 2.5 years now and love it, especially when running on the iPhone 6 with its barometric sensor, but when I heard about a new Indiegogo funded “lag-free” Bluetooth GPS/vario called XC-Tracer, which works with Flyskyhy, I was keen to give it a go, particularly as some big names are flying with it already! So I duly got in touch with the designer, Swiss pilot Koni Schafroth, and asked if he would send me a unit to review, hoping that it would arrive in time for the British Open in Saint-André-les-Alps.
Koni Schafroth is a Swiss paraglider pilot and designer who’s been flying for 25 years. He’s currently working on a project for the European Space Agency, whilst also consulting for the Swiss watch industry, and he somehow finds time to work for Gin Gliders too, where he came up with Gin’s Equalized Pressure Technology (EPT). If anyone’s qualified to shake up vario technology, it has to be him!
The Swiss-made unit arrived about a week after I ordered it and all I had to do before I could fly with it was attach the provided sticky-back velcro and charge it up fully. Of course I also installed the latest firmware and took a look at the config settings file on the provided micro-SD card, but it was pretty much ready to go. (One thing you might want to change straight away is the sinkThreshold – it was set to -5.0 on my device). There’s not much to be said about the external appearance of the device – it’s got a solid case and all fits together nicely. The only control is the red button which turns the device on and off. Two LEDs display the charging status (red = charging, green = charged), whilst a yellow LED displays the GPS status (or USB Mass Storage Device status when connected to your PC). Battery status is indicated by a series of up to five beeps just after the unit is turned on: 5 >= 95%, 4 >= 75%, 3 >= 55%, 2 >= 35%, 1 >= 15%. All units are put through an exhaustive battery test before shipping and any that fail to run for 15 hours in a simulated flight (in indoor use the GPS uses 5mA more current as it is constantly searching for satellites) have their battery replaced with a new one before going through the test again. I got the feeling that the vario settings have a slight effect on battery life (eg. setting your sinkThreshold to -1m/s rather than -3m/s say will mean the device is beeping more and thus will consume more power, though I don’t have any hard data to confirm this, and in any case, there was still plenty of battery left after some of the longer tasks at Saint-André.
Just how responsive is it?
Of course the next thing I did was take it outside to see just how responsive it actually was. You are advised to put it on a stationary flat surface to let it initialise the gyros and GPS after you’ve turned it on, but it can be turned on in flight if you forget to do that (assuming you’ve previously initialised it whilst stationary). This process takes up to a minute before it gives the all-clear with a series of beeps. Now for the fun…! Just lifting it a few cms shows you how well the sensors work – the beeps start as soon as vertical motion is detected, and stop as soon as the movement stops. Very impressive indeed! Have a look at the video below which compares the XC-Tracer with my Renschler Solario and my Flymaster B1 Nav:
You might think that if it’s as sensitive as this then it’ll be too talkative in flight, but this isn’t the case at all – it’s lovely to fly with. For the first time I have a vario which beeps as soon as I hit lift, rather than a second afterwards, and perhaps more importantly, it stops beeping the moment you leave the lift. I’ve flown with it for 21 hours now, with the majority in nice strong Saint-André-les-Alps conditions during the British Open at the end of August, and it certainly helped in finding the core. I also found it useful on glide by helping you to find those lifty lines, and it signals you to tweak the speedbar earlier than conventional varios allow.
I also spent about half an hour flying in very weak conditions in the UK and I’m convinced it allowed me to stay up longer than I would have done otherwise, although I admit that is rather a subjective conclusion to draw!
The question you’re probably asking is how does it achieve this remarkable sensitivity? By using a 9 Degrees of Freedom Inertial Measurement Unit (3 axis gyro, 3 axis accelerometer, 3 axis magnetometer) in addition to the usual highly sensitive pressure sensor… Clever stuff indeed!
Tweaking the acoustics (edited 15/06/2016)
When I first received my XC Tracer in Aug 2015 you could choose between three preset vario sounds, and tweak various settings, however that’s been changed in recent firmware updates.You can either simply use the default acoustic settings that the device ships with, or you can use the online tone simulator here to create your perfect acoustic profile. (Hint: click the black cloud with white arrow button in top right corner to try some ready made profiles). There are five basic settings – volume, climb on, climb off, sink on, sink off – followed by twelve lift or sink data points where you can adjust pitch, cycle, and duty %
It took me quite a while to get it to something that worked well, but it gives me lots of info at different lift / sink rates:
-10 to -2 m/s: typical vario tone here, impossible to ignore – get out of this sink fast!
-2 to -1 m/s: air gently sinking, there might be lift around somewhere
-1 to 0 m/s: air rising gently but you’re still sinking – pay close attention
0 to +1 m/s: max sensitivity in this region for those mincing UK days
+1 to +10 m/s: fairly standard vario sounds here
Tracklogs and USB support
Because it has a built-in GPS, the XC Tracer can record your flight either as a signed IGC file at 1Hz, or else as a 5Hz Google Earth kml file, which are saved onto the supplied micro-SD card.
Of course the benefit of saving it as an IGC file are that you’ll have a backup tracklog in case of any problems with your main instrument, however having a beautifully smooth Google Earth file is tempting 🙂
Edited 15/06/2016 XC Tracer acts as a USB Mass Storage Device when connected to a PC or Mac with a USB cable, so getting copying your tracklogs off the device is super-easy, although you can of course remove the micro-SD card and import it that way. Firmware updates are done by dragging the new file onto the micro-SD card and rebooting the device – very straightforward. (NB. If you have an older device without USB MSD support you’ll need to get in touch with Koni to get instructions on how to install the USB MSD firmware)
As I mentioned earlier, I’ve been using the iOS app Flyskyhy for over two years now, and Flyskyhy’s developer, René, has done a great job getting XC Tracer to work with Flyskyhy. It really is as simple as turning Bluetooth on on your phone, and setting the external vario to XC Tracer. There is also the option to use XC Tracer’s GPS data rather than the iPhone’s GPS and I’m told this increases the iPhone’s battery life, although I haven’t tested to what extent it improves it. I guess the one disadvantage of using XC Tracer’s GPS data rather than the iPhone’s, is that both devices’ IGC files will contain the same positional data, so that in effect you don’t now have a backup tracklog. Hmmm, maybe I should turn that option off given that the iPhone 6 has a pretty good GPS and barometer…
The bottom line
I’ve flown over 20 hours with the XC Tracer and I love its responsiveness – hearing the beep at the same time as you feel the pull from the wing is really great, and conversely, knowing immediately when you’ve left the lift is equally important. I think it really comes into its own in weaker conditions, and now that I’ve bought the unit I can’t wait to try it on a tricky UK XC day. Apart from the “Flymaster growl”, I haven’t missed my B1 Nav’s vario at all, and I have no plans to turn the audio back on again. In fact, I might just try leaving the Flymaster turned off altogether!
As to whether I can get rid of my Flymaster just yet, if I only flew XC and not competitions, then yes, you could do, though personally I would be hesitant to do so just yet, primarily because of the Flymaster’s thermal position indicator which definitely does help you find the thermal again should you lose it. I know René has a thermalling assistant screen on the drawing board, so hopefully this feature will be along soon. If you’re a comp pilot then once René adds route optimisation (which he is working on) and a speed to start instrument, then there would be absolutely no need to spend £400+ on a comp capable GPS/vario. Welcome to the brave new world!
With Christmas just around the corner, perhaps now’s the time to start dropping hints to your loved one to head over to xctracer.com 🙂 (NB. At current exchange rates the price of 345 Swiss Francs equates to approx £230).
Edit 15/06/2016 I am now the UK importer for XC Tracer and the new solar powered XC Tracer Mini – please see my Facebook page for more info and to order.