Re my last tweet. That Coastguard Rescue helicopter that flew over London landed at HM Prison Wormwood Scrubs. Now THAT is unusual...

This map shows it took off from Swansea at 1457GMT and landed at Wormwood at 1618GMT. https://www.radarbox24.com/data/registration/g-mcgw

It actually flew from Swansea earlier today, at around 1349GMT, and looks to have landed in an area of an old RAF base, now MoD St Athan around 1400GMT. No record of how it got back from St Athan to Swansea...

To make this even more interesting, MoD St Athan is home to the Directorate of Special Forces, and Special Forces Support Group. https://en.wikipedia.org/wiki/MOD_St_Athan

The Coastguard Rescue helicopter appears to have taken off again from an area around HM Prison Wormwood Scrubs. It does currently appear to be following the helicopter routes, the blue dashed line in the map. This time (H3). It did NOT follow H10 coming in.

It took off at around 1658GMT and headed towards Farnborough Airport where the tracking stopped at roughly 1709GMT. The path took it towards an MoD Training Area, as seen top-left on this public domain map.

The flight, for reference: https://www.radarbox24.com/data/registration/G-MCGW/1360437731

Also, interestingly, the history of this particular helicopter has flight status for the last 2/3 weeks. The status for the 3 flights today are "N/A".

And it's off again. Given it's general westerly direction, I'd suggest it was heading back to the Swansea area? We'll soon find out... The other aircraft on this map is an RAF C130 Hercules. #GMCGW

Another interesting thing is the squawk code. Online data shows "0023". This is a designated code, and it means "Search And Rescue Operation".

And it looks like they're back on the ground at St Athan in Wales. If it was a patient transfer, I wish them good luck. To the pilots and crew involved in SaR Ops, I salute you. That was a fun few hours, following along and trying to figure things out!