Audible alarm

[plaviator]

Does anyone have ideas about the possibility of incorporating an audible alarm for contacts within close proximity?

[Welsh Pilot]

It is my understanding that this will be incorporated into the software in the near future. However,this is likely to be after the "bridge" module has been launched.

[Robski]

Wouldn't the display system (e.g. SkyDemon) do the alarming function?

To make an alarm come over the headset would require some form of installation into the aircraft's systems, which I think is something that the designers would rather avoid!

[julianwebb]

Rob,

I read on the SD site the position of SD is the SD software should not be deciding when to display an alarm its the job of the CWS to do that and SD just displays the instructions from the CWS - which is the FLARM concept which as you know is the interface PAW uses.

There are various learned articles around about how the Algorithm in systems such as FLARM work and it looks pretty complex so probably we will not see SD build it into the SD software any time soon if at all. What we need to do is see what the take up of PAW is and maybe SD (or of course another vendor) might / will enhance the support for PAW.

As you know the competition is LPAT from Nats and FLARM who want to move into the powered aircraft market as most gliders in Europe already have FLARM. I've looked at FLARM and the cost is about £2K so expensive but it is a CWS with functionality for ADS-B CW warnings also (apparently the RAF have already decided on FLARM but then they have lots of funding) - no idea what price point LPAT will be but NATS might subsidize it as its useful to them operationally and its on the standard 1090 which is a big plus point. Although having worked at NATS as the investment accountant some years ago I think the airlines might be against any subsidy as they will have to pay for it.

Time will tell and time to market might be a key factor.

[SteveHutt]

Julian,

In a PAW/SD setup, to my knowledge, neither device is performing any trajectory analysis to assess which if any traffic is on a converging collision course and is thus a direct threat.

Warning on proximity alone can be problematic. The nearest traffic may not be the one on a converging collision course, so a proximity warning might distract you from other traffic that you really should be worried about.

The exiting NATS LPAT demonstrators do not do trajectory analysis either. They include Funke TM250 technology that I believe does proximity warnings.

The two GA technologies that I believe do trajectory analysis are FLARM/PowerFLARM and the various units that Air Avionics manufacture. Note that these use different algorythms for the trajectory analysis, so might give different answers when presented with the same traffic data. The FLARM algorythms are based on glider flight profiles whereas Air Avionics are based on powered aircraft flight profiles (at least that is what I was told by someone that works for Air Avionics).

Steve

[AlanG]

Hi All
if its audible warnings you're  looking for try,  EasyVFR, it has audible warnings that definitely don't take responsibility from the pilot  simply give various alerts that should direct your  attention to your lookout.  It gives clock and distance alerts for ADSB traffic but only a "Caution Traffic" alert for Mode S traffic based on the experimental signal strength readings being passed from PAW.  (A work in progress by Lee and others including myself.)
I'm sure die hard SD fans will disagree but it is definitely on a par with SD and has features not available in SD.
And it's cheaper.     I'm sure both have their pros & cons but definitely worth a good look.
I'm well impressed with it and it is still evolving on a regular basis.

Regards
Alan

[Paul_Sengupta]

no idea what price point LPAT will be

They were hoping for "sub £1000" which I guess meets the CAA definition of "low cost".

Sky Demon also has proximity/collision warning alarms, but I haven't had a go with it since the days of the original RF module. I'll have to have another play when I get my new RF module.

[julianwebb]

Hi Paul,

I'm based at Chlbolton www.chilboltonflyingclub.co.uk (in between Old Sarum and Popham) but I'm thinking I will need to install POWERFLARM as well as a PAW so will need a PAW anyway (with the RF turned off of course as I will have my TR800H transmitting ADS-B out).

If the PAW commercial release is going to be delayed then I might have a go at building a receiver as that's all I need. LX avionics are waiting for stock of POWERFLARM and I'm also checking the mod requirements from the BMAA so I can wait a while.

I know it costs a lot for FLARM but by all accounts this is the best CWS on the market at the moment. The FLARM installtion is also neat with a 57mm intelligent radar display - looks very nice. I will also have SD running with PAW so I can see PAW equipped aircraft.

I know the risk of a mid-air is very small but the above set up is a lot cheaper than a funeral should it ever happen! 

[chrismills]

I'm currently working on very early version Android app which should run alongside other software (Skydemon for me) and provide audible alerts identifying contacts using the "constant bearing" idea. Data can be grabbed from the PAW and processed by the app so it should be completely independent of any other software running and should work independent of other software.

I'm a bit tied up with real work commitments at the moment but I think I have all the basic elements worked out now and just need to code the app.

Can't provide a time frame and I'm not an Apple developer so  it will be for Android only.
I'll update through the forum as things develop.

regards, Chris Mills

[Paul_Sengupta]

I am familiar with Chilbolton, I'm based at Bourne Park, just across the other side of Andover. 

We'll have to watch out for each other on the screens when flying in the vicinity... (I'm G-DOGG, or at least my aeroplane is  ).

I believe the combination of ADS-B out, Flarm and PAW can't be beaten this side of a TCAS system!

The FLARM part of Power Flarm will come in useful in avoiding Lasham's gliders unless we can persuade all of them to carry PAW as well...

I don't know if the original Flarm is still available but if it is, it's a lot cheaper than Power Flarm, and the only extra that Power Flarm brings to the table is that it receives ADS-B, which the PAW does anyway.

[julianwebb]

Hi Paul,

Yes we are next door neighbors!

Yes the original FLARM is available but I would like as much as possible on one screen so FLARM + ADS-B + Mode A&C (with a frequency strength estimate and FL if available) all on one nice and neat 57 mm screen and PW + ADS-B on the SD. 

If someone could politely ask FLARM to also display PAW equipped aircraft in their system that would be great otherwise I'll still need to look for PAW transmissions on my SD. 

I'm still thinking / researching about where to put the antennas to make sure it all works. Need to see what the options are for PAW then somehow work these in with what is required for FLARM.

Hope to have it all working in the summer sometime.

[EricC]

I have been reading the Flarm manual where it implies that with correct aerial location
a range of 6 to 8km is possible.
To me this seems to restrictive for powered  aircraft.
Am I correct ?

[Dave W]

I've flown an aircraft fitted with PowerFLARM, and it has picked up FLARM equipped gliders at greater than 10km.

For collision avoidance at normal light GA speeds, my thinking is that initial contact at 5km would be more than enough. 

[scsirob]

I've flown an aircraft fitted with PowerFLARM, and it has picked up FLARM equipped gliders at greater than 10km.

For collision avoidance at normal light GA speeds, my thinking is that initial contact at 5km would be more than enough.

Agree. Two GA aircraft cruising head-on at 100 kts would bridge a 5km gap in 50 seconds. Seems reasonable that you'd have plenty of time to look outside and apply see-and-avoid. Not sure about UK, but in The Netherlands, Flight information service warns for other traffic ~2 miles ahead and that seems fine.

I don't understand the urge to see traffic 50 miles away. Nice for ground stations monitoring, but of no use to a GA pilot looking for an extra pair of 'eyes'.

[gvpsj]

A Butterfly unit from LX avionics will transmit FLARM info to tablets; it's a very small WiFi thingy - contact them. It's in my box of things to fit on a dark and dismal no flying day ;-)