"Is FLARM an open standard (or at least an open spec)?"

I think not, from correspondence I have seen. They have licensed others to use the technology, however – “Ozflarm”, etc. See the LX website too. LX avionics Ltd. Radio transceivers, Mode S transponders, variometers, flight recorders .

Chris N.

PS: FLARM posted the following (responding to criticism of their policy – original is at

Flarm hidden protocol, II - rec.aviation.soaring | Google Groups


but you may need to register to read it there)


“Flarm has always communicated openly and transparently, see our website for up to date information on technical and business developments, including IP: Flarm - News In particular we have argued in detail why publishing the RF protocol is currently impossible:

http://www.flarm.com/product/Compati...ations_1_1.pdf

The explanations in that document are widely supported by independent experts. The changes (and underlying motivations) to the v4 version are described since many months here:

Flarm - Updates and yes, they do contain significant enhancements to the RF protocol which did not allow backwards compatibility, see Flarm - Updates

[edited to add PS]

I have also read a little more about FLARM.

It should be appreciated that it would seem its range may be less than two miles. This would partly make sense as you get nowt for nowt. One of the reasons transponders are "power hungry" is they generate a strong signal that is not prone to interferance. FLARM on the other hand relies on low power consumption.

According to the FAA it takes around 12 seconds from seeing another aircraft to avoiding it, so at GA v glider speeds FLARM gives a buffer that is marginal at best.

I think that is another reason why it is unlikely the CAA or EASA would ever "approve" FLARM in its present form.

If it could be done FLARM combined with PCAS would appear to have some benefits.

The best solution would some form of low power ADS-B (Mode-S + GPS vector). Three versions could be available:-

1. Low power / small and light could be fitted to gliders
2. Low/High power switchable - could be fitted to Gilders/GA etc that need to go into controlled airspace periodically (but run low power when in the open FIR to reduce power requirements).
3. Full ADS-B for GA + CAT.

This does not need to be mandated - but does need to be blessed by EASA/CAA. The key would be minimum certification for option 1 and recognition that when in that mode it is NOT suitable for operation in controlled airspace, and should not be required such high standards.

The FLARM hybrid sounds ok but is unlikely to get approval and we really need something that IFR certified aircraft can fit and use legally. Especially that could ultimately feed into the MFD.

PS. FLARM is a sort of ADS-B but uses a private radio channel.

There may soon be some additional uptake of FLARM by the gliding community now that OFCOM has made certain radio equipment, such as FLARM, licence exempt from 1st October. Until now its use in the UK has, technically, been outside that permitted by the Wireless Telegraphy Act.

well all the glider bashing and discussion about needing to be see in IFR conditions, I would be happy if when I am on short finals idiots would stop bumbling onto the runway, sitting there whilst they check their instruments and then get going whilst I go around. If you can't get people to check finals are clear, what hope do you have of people doing a proper scan whilst flying any type of aircraft.
whils I am on my soap box......please stop chucking grit over my plane and into the hangar whilst you do a power check...it is very bad manners as well as extremely poor airmanship.
anyway that is my two pennys worth!
hope you are all enjoying some good weather for your flying...may it last through the weekend. when I shall be flying without a transponder of any kind away from where I am based.

hows the vis?

Better than 3km:}

Rod1
PS I will also be committing aviation tomorrow

On behalf of more safety conscious helicopter pilots, I offer my apology for the poor airmanship of the pilot (not me) in a twin Squirrel who flew southbound, straight over Husbands Bosworth gliding site, at approximately 700 or 800 ft this morning.

I watched his Mode C contact from above, via the TAS overlay on my moving map display and also listened to his RT (on a FIS from Coventry). I was above cloud and a few miles to the east, avoiding the glider site by a safe margin. The cloudbase was about 1300 feet; I would think that he was in a very good position to get "cheeswired" by a launch cable, had they been flying.

ST, Hus Bos are flying even as I write. See webcam at:

The Gliding Centre - Webcam SE


Did you see my last pm?

Regards – Chris N.

Hi Chris, I'll have a look - I've been rebuilding my PC after a total loss of power supply, motherboard and hard drive, so things have been confused.com, to say the least!!

I have been flying around listening to 130.4 whenever I could and never heard a thing, exactly as per last time I tried it after a past discussion.

Aah, now seen it. No I hadn't read it, but will - it might take some time! :ok: