Bell222,
I am sure that could be one of the many rumours that have been floated. However, I know of no substance behind such a rumour.
In my view, if you wanted to get the optimum solution for Surrey and Sussex, why not have 2 heles, each providing a joint Police/HEMS role for 1 county. Or even get the Kent AA involved and provide joint heles in all 3 counties!
It is the most effective solution, but it won't happen because of Empires. Kent AA trust has been nibbling away at Surrey/Sussex for some time. Coordination between police forces is always difficult too.