About 200 jobs are at risk after the Ministry of Defence (MoD) confirmed it is reviewing the future of RAF Boulmer in Northumberland.
The MoD's Defence Strike Command is deciding whether the site - near the Northumberland coast, east of Alnwick - should be closed, along with three other bases in the country.
As well as providing jobs for 700 military personnel and 200 civilians, the base also brings in around £4m to the local economy.
Although the review is at an early stage, Alnwick District councillor Gordon Castle said moves to reduce the size of RAF Boulmer would be a disaster for the area.
He said: "It is a major employer in the district, but it is not just losing the jobs, which would be bad enough, it is the money that comes into the local economy.
"We would catch a cold if Boulmer, or a major part of it, was to close.
"It would be a year-round loss, and a very serious matter for the region."
He said he was surprised that Boulmer was included in a review looking at closure when the base recently announced expansion plans.
Boulmer is the RAF's only base in the North East, and, as well as protecting UK airspace, it also provides a vital air-sea rescue service.
Berwick MP Alan Beith said the station had "tremendous community significance" and Hexham MP Peter Atkinson said the plans were "a great concern".
Boulmer's commanding officer Group Captain Nick Gordon said if the station closed the MoD would have to consider where to base 202 Squadron and search and rescue teams.