If nothing else comes out of changing operator to CHC midway in the contract, it sends a clear signal to all operators in the NS (Bond, CHC, Bel Air, Bristow, NHV, Dancopter, Wiking Helicopter, etc.):
Even though you have fulfilled your part of the contract going from year XX to year YY, we have no problems in changing to another half way between XX and YY.
Ethic behaviour?