General aviation in UK squawking 7700

[Micke_xyz]

What's the deal with the general aviation(?) in UK squawking 7700 now and then? I large portion of my received 7700 alerts in FR24 android app comes from small planes in the UK. What are they up to?

/Mike

[KyleG]

If you mean the G-BY reg'd aircraft, those are training aircraft for the armed forces, and the 7700 is part of their training.