however, although the possibility that all the ATCOs could leave is remote, there are contingency plans in place to train up enough ATCOs to man the tower in both positions in the 6 months phase-in period.
Like another well known contract which lost nearly half the staff at contract change? The remaining staff were told there were "contingency plans" - 3 months down the line there's still a darkness at the end of the tunnel instead of a light.
Definition of an ATC contractor - someone who's prepared to shaft employee and customer alike in order to turn a quick buck
