Approval for the new radar system at Ronaldsway Airport is yet to be granted.
The UK Civil Aviation Authority has carried out an audit on the new equipment but has yet to sign off on it.
Concern has been raised as to how much money is being spent on the project and on keeping the old machinery operational.
The original contact was for over £3 million - with almost £3 million already being paid out to the contractor.
Infrastructure Minister Laurence Skelly says he hopes the changeover is imminent:
Watch film about Island mine defuser in Ukraine
Card game features Island's feathered menaces!
Airport passenger figures up by one per cent
Huge drop in safety incidents at hospital
£14 million owed in student loans, says government
£250k needed for Onchan street lights
Island homebuilder could be wound up
Yellow weather warning issued for Sunday
