From what I hear from guys who upgraded recently, you stay on your current contract as it is, so the older BRK guys like me get there captain hourly rate which is currently higher than the new contract rate been offered.
once the 5 years is up, well I have not heard of anyone that has expired there 5 year BRK as yet as most guys I fly with that have been here more than 4 years are on FR contracts.
I guess the BRK thing is all still a bit new on a mass scale, will have to see what develops.
I can say that if mine expires in another (2 years) that will be after been in the left seat (should I choose) for about 18months, if I am expected to suddenly chop my wages and loose the 3% to a random mafia accountant and then pay tax in Ireland (somewhere I have been twice in my life for about 8hrs total) I will be out the door as soon as I can!
And you can take that to the bank!