Tony, if you have been in the Middle Wallop 'massed crash' you will know that you can't just turn up and do it - it needs practise and lots of it. It also needs organisation and briefing by someone who knows what close formation (and I mean close formation) is all about. Usually it ends up as a line abreast hover taxy (frequently downwind) down to the hover from 200 feet - normally between 1/2 and 1 rotor span from your neighbours. There is not a lot of room for error and I know lots of pilots who have had very narrow escapes during the practises. I have participated several times in both Lynx and Gazelle and it always concentrates the mind wonderfully being in close formation with up to 100 other helicopters - the bar is usually well attended afterwards!