GPS outage leading to ADS-B OUT not working?

Wow that’s a lot of jamming including inside the EU. If GPS is down over an area it can shut most airports in that area plus cause traffic jams at the few that still maintain traditional infrastructure (and potentially a number of fuel emergencies). Remind me why we’re dismantling the traditional navigation infrastructure again in favour of a single point of failure?

Parthurnax wrote:

If GPS is down over an area it can shut most airports in that area plus cause traffic jams at the few that still maintain traditional infrastructure (and potentially a number of fuel emergencies).

Yes, but luckily, the areas highlighted on the map (at least those “northeasterly” ones) are quite sparsely inhabited. Therefore, they have no major airports, only a few small regional ones. Tartu airport was in the news for deciding to reinstate their ILS/DME.

Peter wrote:

To emit ADS-B OUT, SIL=2+ you need a WAAS/EGNOS GPS input to the ADS-B OUT emitter (in Europe this is usually a Mode S transponder).

SIL is not what is used to determine if the signal is usable or unusable. NACp, NACv and NIC are used. ADS-B Out is a performance specification and any position source that meets the performance requirements may be used. Some position sources will meet the requirements a greater percent of the time. Most installations use SBAS (WAAS or EGNOS) capable GPS, but it is not a requirement. TSO C129 and TSO C196 are GPS TSO that are not SBAS capable but may be used as the position source, although TSO C129 GPS receivers are not likely to provide the necessary parameters and a Non SBAS C196 position source may not meet the requirements a greater % of the time than an SBAS based position source. New dual frequency L1/L5 GPS systems will end up meeting the requirements similar to SBAS based systems. There are new RTCA standards in the works for multi frequency, multi constellation systems being defined that will also support ADS-B Out as a position source.