If it was a training excercise why did they need the other helicopter, also no planes landed at stansted for about 30 mins while they were in the area

One landed at the Princess Alexandra Hospital while the other circled at low altitude. It missed the main Helipad and landed on the grass, probably deliberately due to the Helipad being a bit tight for a big machine like that. It was quite an impressive sight and I was only a few yards away at the time. Sadly I wasn’t able to find out why they arrived as I got called away before anyone got out. It stayed about 40 minutes.

Thanks Super Nimrod, i knew one landed somewhere but couldnt tell where. The one circling left a long time before the one on the ground then, what do you think it stayed for?