LAA refuse approval to connect PAW to Funke transponder (ADS-B out)

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LAA refuse approval to connect PAW to Funke transponder (ADS-B out)

Post by martc » Fri Jan 15, 2021 5:18 pm

We completed a permanent installation of Rosetta Pilotaware at the beginning of 2020 including connection to our Funke TRT800A Mode S ES transponder with latest firmware (5.3). Carried out by professional avionics engineer who confirmed ground tests and that ADSB working correctly, set to SIL=0 as non certified GPS from Pilotaware. Sent off the relevant mod forms to LAA last year. Just (January 2021) had the following response from LAA saying that they won't approve the connection for ADSB out because the "TRT range does not comply with the ETSO standard". I have seen nothing on this anywhere, with CAA /LAA and everyone else including Pilotaware encouraging installations of EC units and in particular connections to ES capable transponders for ADSB out as a preferred minimum. Advice?

LAA response to modification forms sent in:

"Unfortunately, we can’t approve any ADBS-out connection for the Funke TRT series transponders as they do not possess the appropriate approval. The TRT Series is not approved to ETSO Standard C166B, therefore the ADSB out function can not be approved for use until this certification is sought by the manufacturer. The TRT series is sold as “ADSB Ready” but does not necessarily meet the minimum performance requirements of the ETSO. Unfortunately all transmitting avionics installed in LAA aircraft must hold the relevant approval from the CAA, EASA or FAA.

I am sorry this is not the news you wanted to receive. However, you may still use the pilot aware device in your aircraft as standalone electronic conspicuity not connected to that transponder. If you permanently install it you will just need a PMR in your airframe logbook from your inspector."

If this is correct, it throws into serious question why we are being encouraged by all and sundry to spend money on fitting devices which the regulators won't approve. I am struggling to see how this can be right, especially as I have seen nothing on this subject (LAA approval declined) for this elsewhere.

Also the Funke TRT800A transponder is in the list of approved devices (page 16) in LAA's own Technical Document dated December 2020, with no mention anywhere in that document of compliance requirements to ETSO C166b:

LAA Technical Leaflet TL 3.03: Aircraft Avionics Installations ... ations.pdf

Jeff Ellwood
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Re: LAA refuse approval to connect PAW to Funke transponder (ADS-B out)

Post by Jeff Ellwood » Sun Jan 17, 2021 7:33 pm

unbolt your transponder and fasten it with strong velcro, then it is also portable!!!!
The display part of the transponder can still be in the panel.
Just a idea to try and get round the total stupidity

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Re: LAA refuse approval to connect PAW to Funke transponder (ADS-B out)

Post by martc » Thu Jan 21, 2021 10:06 am

LAA have just issued (good) news update confirming a resolution reached that the Funke can now be approved with non-certified GPS source installations, providing SIL values set to 0. Excellent.

Well done all at LAA for this sensible and pragmatic solution! :D
Last edited by martc on Thu Jan 21, 2021 10:24 am, edited 1 time in total.

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Re: LAA refuse approval to connect PAW to Funke transponder (ADS-B out)

Post by joehadley » Thu Jan 21, 2021 10:07 am

Hi All,

Joe from LAA Engineering here. Here is a positive resolution the team has worked on to get this combination of devices approved. Thanks to all who got in touch to help us find this solution. You know who you are :D
To those of you I wrote to rejecting your application I'll be in touch soon to get it sorted.
If you've any queries please contact LAA Engineering directly :wink:
As you may know it is possible to connect an uncertified GNSS (GPS) receiver to a range of Mode S transponders in LAA aircraft to provide uncertified ADS-B Out, which we’ve been approving since 2015 following the successful NATS trial.

It was recently brought to our attention that CS-STAN Issue 3 CS-SC005a (issued in 2019) requires that the transponder for such installations must be certified to ETSO-C166b, which covers the approval of a transponder to transmit ADS-B Out. LAA technical leaflet TL3.03 and LAA procedures also require that “transponders installed in UK aircraft must be of a type that has undergone an appropriate approval process by either EASA, the CAA or the FAA”. Given the lack of CAA rules on this subject, LAA interpret this requirement as a transponder providing ADS-B out must also be certified to ETSO-C166b. For the majority of ADS-B installations approved so far, this certification requirement was not of concern as most installations used a Mode S transponder that was certified to ETSO-C166b (ETSO certifications can be checked here).

Upon further research, LAA Engineering understands that a change in the wording to CS-STAN CS-SC005a ‘Configuration 3’ will be made with the next revision of CS-STAN which will remove the requirement for ETSO-C166b certification of the transponder. Please see this EASA FAQ here.

LAA Engineering is therefore satisfied that ADS-B Out installations with a transponder that is not certified to ETSO-C166b is satisfactory for ‘uncertified’ applications. The transponder must still be compliant with an appropriate certification for Mode-S operation, installed in accordance with the manufacturer’s instructions, and the ADS-B Out quality indicators must be set to SIL/SDA = 0.

All previously approved ADS-B Out connections are still valid and any LAA/MOD7 or LAA/MOD14 applications that were previously rejected can now be processed normally.

John Brady
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Re: LAA refuse approval to connect PAW to Funke transponder (ADS-B out)

Post by John Brady » Sat Mar 06, 2021 6:14 pm

Hello Joe,

Thanks for your resolution and advice on ETSO166B on the recent post.

I have an existing LAA approved FUNKE TRT800 installation with an uncertified GPS for SIL=0 in G-RUVE. I just bought a Trig TN72 TABS (which is TSO C199 approved) with the intention of upgrading the ADS-B(out) to SIL=1 as set out in LAA/MOD 14 paragraph 4.

Given the recent difficulty, is that something I can apply to do now, something I may be able to do in the future or have I wasted my money?


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