To be able to do a particular flying job, in very general terms, you need 2 things:
- to be able to fly the type of helicopter that the operator uses [aircraft type competency]; and
- to be able to fly the type of task that the operator carries out [confusingly called line competency]
For the first you need a type rating which you get after doing a type conversion course and passing a flight test. You also need to be current and prove your continued currency and proficiency at intervals.
The latter can be a bit more difficult. And this is what lots of people without aviation experience struggle to understand. Helicopters fly doing a whole host of different activities. These different activities require quite different skills and knowledge. So because you can do one activity, does not mean you can do the other, even if it involves flying the same helicopter type.
The training to carry out a particular operation is called line training. This comes from "flying on the line" (i.e. during normal operations). However the total package necessary to achieve line competency takes a bit more than just a few hours practice in the aircraft. Or at least it can do for some tasks.
Generally the easiest way for an operator to get suitable people is to poach them from another operator. The second best way is to find someone who has similar skills and experience to those needed for the particular line activity.
If a pilot fits the line competency target, but does not have the type rating, then it is RELATIVELY starighforward for him to get the type rating (not necessarily cheap).
Who pays for a pilot's type rating is a matter for straightforward contractual negotiation. If the operator pays for it, then to stop another operator poaching the pilot, they will often try to bond that pilot and prevent him from leaving for another employer without paying back at least some of the cost of the type rating.
Does that help at all?