Flymaster B1 Nav review – part 2, UK xc flying


The first part of my review covered using the B1 Nav in competitions – this follow-up covers its use during a 43km flight I made from Westbury on Sunday 20th June.


Apart from setting the altitude units to feet, setting Alt and Alt2 (to zero) and removing any tasks you might have set up previously, there’s nothing much to do.

I’d previously set my six UDFs to:

Alt 2 Cur GR Thermal distance
Max height GR to Goal (just in case I declare a goal) Dist TOff (dist to takeoff)


I didn’t pay much attention to the unit whilst ridge-soaring (apart from the audio of course, which works very well as I mentioned in part 1), so it wasn’t until I was high up having left the hill that I noticed that certain things weren’t as they should be, namely:

  • distance to take-off not visible under compass
  • Max alt UDF displaying in meters not feet
  • Alt2 displaying in meters
  • Integrated vario displaying in 10s of meters/sec (ie. 2.1 m/s displayed as 21). I was expecting 10s of feet/min (ie. 400 ft/min displayed as 40)

Once I’d noticed this I changed the altitude units back to meters and all was fine, though I much prefer feet rather than meters when flying in the UK. (I emailed the developer, Cris, and he acknowledged these were bugs which will be fixed in the next firmware release).

Last thermal indicator

I found the growling buzzer very useful in working weak lift and then finding the thermal proper, however I do think the last thermal indictor some tweaking – I had been on a glide for a couple of kms and found a weak area of lift, really just zeros. The buzzer was doing its stuff nicely, but even though I did quite a few 360s in this weak lift, the last thermal indicator still showed 2km behind me rather than registering this new area of albeit weak lift. It turns out this is because a thermal is only detected when the integrated vario is above 0.5m/s.

(I have suggested to the developer that this threshold become a user adjustable setting. I also said that there’s really not much point in knowing that the last thermal is 2km away as I think you’re never going to head back that far to reconnect with it. Cris also said he’s currently working on some other ideas for improving thermal detection).

But the upshot of this was that I couldn’t use it to guide me back to the weak lift had I searched (and failed to find) some stronger lift nearby. Not a major problem, and I’m sure it’ll be improved in a future update.

Wind indicator

As I noticed in Slovenia, I think the wind speed calculations are over-reading. I was noting the max (50km/h) and min (8km/h) GPS speed as I was circling in a thermal, which by my reckoning gives a windspeed of 21km/h ((50-8)/2), however the unit was saying 40km/h. I’m hoping that Cris will sort this out soon too.


Apart from these dissapointing little bugs which I’m sure will be fixed soon, the unit performed very well. Ultimately though, the key requirement for UK xc flying is a decent audio vario, and the Flymaster vario is very good indeed. Other than that, the other key feature is airspace mapping, and at this point in time (and probably in the medium-term too) the B1 Nav doesn’t incorporate any mapping at all, so unless you’re keen on paper maps, you’ll still need a Garmin map unit or a PDA to display airspace.

Knowing the windspeed and direction is helpful but not essential, likewise the last thermal indicator (I’ve managed without an instrument telling me this for twenty one years!) so if you think you’re never going to do any cats cradle type competition tasks, I’d recommend you save your money and buy the Flymaster B1 instead (which retails at £179), and put the money saved (£320) towards a Garmin map unit which you’ll probably want anyway. The B1 has the same excellent vario and display, and if you want to know your glide ratio, or work out the windspeed ((max-min)/2), or do simple declared goal flights then your Garmin will do that just fine.

Of course, if you’re lucky enough to have money burning a hole in your pocket, then definitely go for it, it’s a great piece of kit (as long as you can put up with meters for the time being that is 🙂 )


I used firmware version 1.16 during the flight. Version 1.17 was already available, but it still has the bugs I discovered in it.

Update 1st July

Firmware v1.18 was released yesterday which fixes the bugs I noticed – I’m looking forward to flying in feet again! Thanks for the quick work Cris.


~ by Tim Pentreath on June 23, 2010.

One Response to “Flymaster B1 Nav review – part 2, UK xc flying”

  1. […] part two I will evaluate how it performs for typical UK xc […]

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