Single word response. APACHE.
This reminds me of a challenge/ response password. This Q post might be Q authenticating himself.
How often does a comms failure happen with aircraft? Any emergency redundancy system they could use to report a problem?
Also good watching, keep us posted.
Me again. I'm not a planefag. Most of the flights that would have flown over London are spinning around too. I have no idea what I'm doing, it may be nothing, or maybe the flights are being redirected?