A400 vs. gliders
 

Would an A400 crew have any way of detecting a FLARM equiped glider, other than MKI Eyeball?

No, and they wouldn't detect an ADS-B (only) equipped glider, either. Perhaps a transponder equipped glider (TCAS).

As the A400M is an Airbus aircraft then if ATSAW is embodied then it will detect and display ADS-B only traffic as long as SIL=1+ and SDA=1+.

Here is what the ATSAW symbology looks like:


https://cimg8.ibsrv.net/gimg/pprune....ee8fad430.jpeg

https://cimg8.ibsrv.net/gimg/pprune....0a80be923.jpeg
https://cimg3.ibsrv.net/gimg/pprune....327b85552.jpeg

The same goes for Voyager too - with ATSAW embodied and enabled then it could see a glider if it is emitting SIL=1+ and SDA=1+ ADS-B. This is what Airbus say about ATSAW for the A330:

However, not many gliders even have a transponder.

However, not many gliders even have a transponder

A lot of gliders are technically incapable of accommodating or supporting the power requirements of a conventional transponder. Also, would not the slow speed of a glider be filtered out by most TCAS systems?

I am not aware of any technical limitation for that. IIRC ACAS is a challenge-response interrogation device, where possibly a high relative speed with doppler effect might introduce some challenges on the transport layer.

But surely it was designed to function even for 2 stationary helicopters.

Whilst traditional transponders might be out the window, something like SkyEcho in the UK is extremely well suited to gliders, especially in areas where they might conflict with conventional aircraft.

https://uavionix.com/products/skyecho/

there's also a CAA rebate available at the moment for them, so it'll cost you the dizzy heights of £250 in the UK for powered GA or for gliders.

https://www.caa.co.uk/General-aviati...cuity-devices/

The B Word

Could you point to the information that says certain ADSB transmissions won't be displayed ? The images above clearly show the combination of types "on offer" but I would have thaought that a warning such as "Caution - not all ADSB traffic visible" would be part of the instructions.

Is it more the case that traffic below the SIL/SDA level wont generate an RA but will still be shown - just like Mode A transponders?

Getting back to the original question...FLARM doesn't talk to anything other than another FLARM receiver. The RAF retro fitted FLARM to their Tutors for greater SA. A few years ago I was gliding over Oxfordshire when I saw a FLARM contact coming towards me a 1000' lower (a powered ac - this can be configured in the set-up), it was the BBMF Lancaster and the Canadian one with Spitfire and Hurricane escort. So yes to the question if you have the kit.

Thanks for the replies - interesting and good to know that some types of TCAS can see non-transponder ADS-B

" FLARM doesn't talk to anything other than another FLARM receiver " That's not true - it talks to ground stations, which then rebroadcast the gliders information in a format usable by PilotAware (which is used by many light aircraft).

The Shawbury helicopters also have FLARM

ZeBedie Wrote:

[QUOTE]That's not true - it talks to ground stations, which then rebroadcast the gliders information in a format usable by PilotAware (which is used by many light aircraft).
[/QUOTE

Jeeez... splitting hairs, the ground base is a FLARM receiver and yes sites like Spot the gliders! then can be used.

May I ask you a question, if you know so much about FLARM why ask the question in the first place?

I thought for a moment when I saw the title you meant replacing A400 with gliders!

Getting something to use as a tug would be interesting.

My Trig TT22 transponder can run about 6 hours off one of my glider batteries. I'd love to enable ADS-B Out, but the regulatory hoops in Canada have not yet been laid out with any degree of clarity and in the US they are seriously gold plated.

In the meantime my transponder makes me visible to TCAS.

@ETOPS, there is an RTCA spec (DO-317B ) that says that only traffic with SIL and SDA equal or greater than 1 should be displayed.

SkyEcho2 is technically capable of SDA=1 but due to the way CAP1391 is written, SDA is set to 0 at the moment.

It will also depends if the RAF ticked the box for the option to have ADS-B in

Given the amount of flying the RAF does in the company of aircraft equipped only with FLARM or other GA systems like PilotAware, you'd think they'd equip with the kit to see these aircraft - the cost would be truly trivial.

Thanks xtophe80

I take comfort from the info that even though my ADSB signal is SIL=0 it is via my Mode S transponder thus I will still be detected. What we need now is the agreement that so called
"uncertified" GPS sources have enough accuracy for this application. One of my portable devices reports a CEP in terms of 16ft which is less than my wingspan......

Pic St Loup
 

The montpellier gliding club's glider fleet have had conventional transponders for at least a decade after an airbus hit a glider in open airspace. Controller error and knee jerk was the dgac nicking 2,000 ft of open airspace but the club negotiated using closed airspace with mode C transponders powered by a couple of burglar alarm lead acid batteries. Autonomy was generally at least 5 hours in spite of the cold OAT during wave climbs. Standard calls either with Montpellier approach or Istres military towards the rhone valley..Then onto Airways with Orange. Only negative is some of the controllers appalling English which often led to them having to listen to my french.

ETOPS

Here is a link to the Traffic Awareness Beacon System (TABS) requirements under TSO-C199. TABS was designed as a standard for certified ADS-B In to receive - ie. ATSAW, CDTI, ACAS-X, etc...

https://www.icao.int/APAC/Meetings/2...20briefing.pdf

To save you wading through it, here are the parameters of interest:
https://cimg9.ibsrv.net/gimg/pprune....670d13908.jpeg

Someone mentioned SkyEcho. This Low Power ADS-B Transceiver (LPAT) can do SDA=1 and SIL=1 and does so in Australia under the Australian regulations. It also has a TSO-C199 GPS and so it has everything needed for the UK once the CAA allow it under CAP1391 and people enable SDA=1 via the software. At £250 after the CAA rebate, then it’s a ‘billy bargain’.

It truly wouldn't, unlike GA aircraft they can't just velcro something to the instrument panel so the cost soon becomes excessive when trying to integrate into a glass cockpit.

What depressing times we live in;- An ultra low cost, easy to install and operate solution can be talked up to such a high price, it becomes far cheaper to kill a GA pilot, maybe a service flight crew/s and smash up a very expensive national asset.

If you do that for every capability that is required you end up with a pretty high workload cockpit. The difference between commercial, GA and military is considerable in that Mil ac are continuously having new equipment fitted. If you had a "bolt on" collision warner, how do you give audio to the crew? If not, how do you expect a crew to be alerted to a threat.

If you have a bolt on threat Warner as well, which do you put where? How do you prioritise audio from the threat Warner and collision warner? The list goes on, but cockpit design is not as simple as "build your primary instrument scan and then bolt a bunch of stuff round the outside of it".

Believe me, no one is a bigger advocate for "quickly, cheaply" than I am, but at least some of the method isn't madness or blatant profiteering!

It’s not that difficult;- The audio is no more than a pilot operating a radar advisory service where the ground controller calls the pilot out of blue with a target bearing;- With this they hear a computer generated voice and then look in the clock direction of the light on the matchbox sized display. Surely they can cope with that, bless em.

I amazed with the sensor kit available now you need any equipment upgrade;- military kit is highly optimised to find highly uncooperative targets, monitoring a massive band width, whereas these units are electrically screaming “Hi I’m here, I’ll even give you my GPS coordinates” on a well known frequency.

Unfortunately it is indeed that difficult.

You can't just lob a system into a cockpit or flight deck (even for commercial air transport), it has to be integrated. Potential interference with FBW, displays, warnings etc, all have to be quantified to ensure there are no unwanted impacts on airworthiness. Where do you take your power supply from? Current running through wiring generates an EM field, so you need to know what that does to the rest of your systems. Where do you put the display? Does it interfere with (eg) sight lines during AAR, or generate another blind spot in the pilot's field of view? What training do you need to rank FLARM warnings with any others your aircraft might be producing? Will the display interfere with escape systems (contact with equipment during ejection and the like (OK, not A400))? Is the display compatible with NVGs? What is the logistics tail? Mean time between failures? MEL considerations and operating regs? Servicing? Documentation?

There will be other technical questions too.

How do you get the computer generated voice into the pilot's ear? The one from the box of tricks won't be heard over the background noise in the cockpit of a fast jet or helicopter so you have to integrate it into the comms system, which is a whole thing in itself given TEMPEST testing requirements. Plus you'll probably be needing an external antenna as the amount of metal in most air-frames attenuates the signal too much which as detailed above is a nightmare to design.

Of course I'm amazed the GA world is insisting on using its own propriety standard when there are two internationally recognised ones available, so it looks like we can all play the over-simplifying someone else's problems game.

This reminds me of the discussion about securing cockpit doors before 9/11. The objection was that a locked door could cause structural issues if the cabin were decompressed during a hijacking.
Funny how quickly that got fixed subsequently....

Not really, a locked door definitely works at stopping people getting into the cockpit.* I've yet to see any reliable figures for the percentage of GA fitted with FLARM to be able to estimate a likely reduction in mid air collisions and without that who's to say it's the best use of a limited budget?

*Even if that would be a good thing, see German WIngs 9525

The FAA mandated that all USA carriers should have locked cockpit doors well before 911. The senior cabin crew member had a key.