FED - thanks for taking the time to explain this, really appreciated.
I suppose if all the departments on each of the rigs/platforms coordinated their rotas they could use a bigger helicopter and costs could come down or the bigger helicopter could visit more than one rig?
I suppose this is being looked at all the time by the operators and manufacturers its just that one thinks that all the effort that goes into designing and building a 20 seat helicopter can probably be just as easily done for a 30 seat one?