3 a/c squawking 7700 in 30mins into Moscow
 

Any ideas why?
https://cimg7.ibsrv.net/gimg/pprune....a94b456da3.png

Perhaps all 3 were carrying medical supplies and were using this to get an expedited landing and off-loading ?

Surely thats not standard practice? They could have just declared that to ATC.

Nothing is standard practice these last few months, so who know! The statistical chance of 3 aircraft declaring an emergency at the same time, in the same airspace is pretty long. Where did the flights originate/arrive ?

1681 from Naberezhnye Chelny (NBC)
1311 from Mineralnye Vody (MRV)
1186 from Volgograd (VOG)

The thing is there's so little in the air at the moment, why go to the bother of squawking 7700 just to land a few minutes earlier?
And 3 at the ame time isn;t going to guarantee any priority, just give the ATC a headache.
Still seems bizzare to me.

NO ! It’s not for that ! Not allowed . Full stop.

I’lol give you an actual pilots view..... I’d suggest it could well have been fuel emergencies , if Moscow was very busy or they all came from the same direction with , say, unforecast headwinds that hammered the reserves