Puma helicopters are currently based at RAF Aldergrove
Hundreds of RAF personnel are to be moved out of Northern Ireland, Armed Forces Minister Bob Ainsworth has said.
He said it had been decided to relocate 230 Squadron, based at RAF Aldergrove, to RAF Benson in Oxfordshire.
"This will establish a coherent Puma (helicopter) force on a single site, enabling the improvement of Puma force capability," Mr Ainsworth said.
About 100 of the 420 civilian staff at the County Antrim base could be made redundant because of the move.
A spokesman for the Ministry of Defence said they were attempting to minimise compulsory redundancies.
Negotiations have begun with the trade unions about voluntary redundancies and possible moves to other government departments in Northern Ireland.
There will also be jobs available at RAF Benson for those who are prepared to move to England.
About 600 of the 700 RAF personnel on the Aldergrove base will be moved to England, along with most of the current 500 dependants.
The MoD then intends to relocate 38 Engineer Regiment from Massereene Barracks in Antrim to RAF Aldergorve. It will then be closed.
The relocations are expected to be completed by the end of 2010.
The cut-back is unconnected with the peace process reductions in troop levels and base closures which were finally completed in Northern Ireland by the MoD last autumn.
Mr Ainsworth said: "These changes will not impact on our commitments in support of the civilian authorities in Northern Ireland.
"Aldergrove will remain a military flying station for the Army Air Corps for the foreseeable future."
He said the RAF would continue to use Northern Ireland airspace for training and a limited number of RAF personnel would remain in joint or specialist appointments in units in Northern Ireland.