ATC Transponder FAULT Nicosia Airspace

[CPDLC NeedsReset]

Hi all,
I am wondering what is going on in the Nicosia Airspace between waypoints APLON-LEDRA (L/UL609) inbnd TLV coming out of central Europe. Pilots are reporting ATC TRANSPONDER Fail on different Aircraft always in the same area.
When testing on ground in Europe no faults can be found and the system works fine everywhere else.
Anyone else experiencing those problems?
Reading the Notam which points out that the Russians "testfire" rockets close to the Syrian border I guess I don´t even want to know what is going on in the Areas LCD-3/4/47. Just want to make sure it is not an aircraft related problem with the transponders. Would save a 100% of time.

[FE Hoppy]

Is it transponder or ADS-B?
Ive got a feeling there is some GPS sculduggery at play.

[STBYRUD]

I have not seen this happen around Nicosia, but on both B777 and B737 certain models of transponders are susceptible to interference from transmitters on the ground (the original bulletin mentions television transmitters) - that could be one possibility... There is a rather large antenna farm belonging to the RAF at Akrotiri

[rak64]

You talking about this installation?
https://en.wikipedia.org/wiki/Over-the-horizon_radar
https://www.sigidwiki.com/wiki/PLUTO_II_OTH_Radar
Over The Horizon Radar | Thames Amateur Radio Group

[wiggy]

Ive got a feeling there is some GPS sculduggery at play.

Quite probably..we’ve had warnings (and reports) of GPS jamming/ interference in the area...suspect seems to be the Russian Navy.

[physicus]

over the horizon radar is always very low frequency stuff as reflection on various layers is used to get the signal over the horizon. those layers are largely transparent at 1090/1035 MHz.

I’d go with intentional jamming/RFI causing at ModeS frequencies. That’ll confuse the XPDR system.

edit: if it’s only GPS jamming or spoofing (which is equally easy to do) you’d get various IRS nav disagree messages I’d presume.