Highfive, 'Clearly the contracts cannot be worth much if an employee can be forced to take 'unpaid" leave?'
The contracts are completely worthless when the previously agreed terms no longer suit Norwegian. See my earlier post about the captain that was terminated for refusing to give up his Gatwick contract to sign a Spanish one.
OSM advertise their contract as permanent employment. In reality it is no more than a rolling 3 month contract if the employee can be terminated for attempting to defend the terms in his existing contract. You accept what is forced upon you or you are out.
Anyone considering an application to Norwegian needs to be aware of the reality that others before them have experienced. I would only apply to this company if you have no other option. Proceed with caution.