I live in London, UK and heard 3 planes flying above my place so I checked flightradar.

This plane: https://www.flightradar24.com/GOLD01/30c1850f

• Call sign: GOLD01

• Text on the machine (photo): G-ZACHS

Goldman-Zachs?

• The plane started from RAF airport Northolt.

• Then 3 and later 5 RAF fighter machines came up.

• Finally the GOLD01 landed on the same airport.

• RAF planes disappeared from the map.

EDIT:

It has landed, but you can still see the trajectory here:

https://www.flightradar24.com/data/aircraft/g-zahs/#30c1850f

Same link available on the link above, just select Show History.

On the second page - scroll the map down. Some info available below the map.

EDIT 2:

Someone rightly pointed that the text on the plane has H, not CH, which seems to be a registration number:

https://www.radarbox.com/data/registration/g-zahs

The above page helps to track the flight history. Interesting: on one of the trips the plane didn’t have a transponder ON when starting so it was “first seen near Aman” instead of on the airport as we would expect.

The next flight shortafter was from London to Coningsby (QCY/EGXC).

It seems it could be just an coincidence that the “civilian” looking plane owned by the military has a registration is G-ZAHS (not Zachs with “C”) while they gave the flight a call name “GOLD01”.

We live in a world of coincidences. Aren’t we?

And these 3 RAF fighter planes (at the end of the trip there were 5! and disappeared quickly) - this was all a coincidence.

EDIT 4:

You can see this plane on a video LIVE right now here:

https://www.youtube.com/watch?v=NBif8EmRFUA

Mystery solved or not really?

Twenty Two Eurofighter Typhoon FGR4 callsign 'WARLORD' & ‘COBRA’ 29 Squadron stationed at RAF CONINGSBY are set to depart for the King's Birthday, Trooping the Colour. It is a military ceremony that has been held to mark the official birthday of the British Sovereign for more than 260 years.

Funny to hear people talking live on that video broadcast link.

Could that be Charles going for Typhoon ceremony?

Flying back, although not necessarily towards London, …, target airport not revealed yet, … finally Lossiemouth.

https://www.flightradar24.com/RRR1605/30c25d2d

Ad here we go:

https://www.raf.mod.uk/news/articles/the-kings-birthday-flypast/

18 Typhoons from RAF Coningsby and RAF Lossiemouth perform the special formation for His Majesty The King.