Union anger at Hial's planned shake-up of air traffic control
Air traffic control for five Scottish regional airports is to be undertaken centrally from Inverness, Highlands and Islands Airports Ltd has announced.
The move involves Sumburgh, Dundee, Inverness, Kirkwall and Stornoway.
Hial said the change, which would be phased in, would modernise air traffic control.
But the union Prospect said the plan puts 60 jobs at risk and described it as "poorly thought through".
Unmanned towers would feed information to a new combined surveillance centre at New Century House in Inverness.
The building near the Kessock Bridge at Inverness is currently the offices of Highland News and Media, publishers of the Inverness Courier newspaper.
The change would be phased in over the next few years, but Prospect understands it could be 2027 before it takes effect at Dundee due to the complexity of the air space there.
Prospect said the proposals would involve downgrading air traffic services at Benbecula and Wick John O'Groats airports, could mean compulsory redundancies and were being pushed forward without prior consultation with staff, communities or passengers.
The union said the sites would have a flight information service officer service, which would offer pilots information about the condition of the airfields and weather but not the flight paths of individual aircraft.
Prospect negotiator David Avery said: "The proposals to downgrade services at Wick and Benbecula are staggering.
"Within these small communities the loss of even a few jobs like this is the equivalent of losing several hundred jobs in Glasgow and Edinburgh.
"It is inconceivable that such far-reaching changes can be brought in with the paltry level of consultation and transparency we have seen."
But Hial managing director Inglis Lyon described the new centre as a "significant step".
He added: "It will allow us to move forward with planning and procurement of the relevant systems to safely deliver a state of the art air traffic control management system and give additional clarity to colleagues and stakeholders as we deliver this complex and challenging programme.
"Our focus continues to be on aviation service delivery and providing a safe, modern and efficient means of handling aircraft for the regions and the islands in the future."
Transport Scotland said the move was part of a wider programme to ensure remote and rural communities "continue to benefit from sustainable air services in the future".
A spokeswoman said: "We recognise that this is a major change for the organisation.
"Hial has engaged extensively with staff, local authorities and other stakeholders throughout the process and we expect them to continue to engage and consult as it implements the programme."
The Western Isles local authority, Comhairle nan Eilean Siar, said the change could see the loss of up to 20 jobs in the islands.
It has called on the Scottish government to intervene.
Leader of the comhairle Roddie Mackay said: "This is not an attitude or approach we would expect from a Scottish government owned company."
Transportation committee chairman Uisdean Robertson added: "It seems to me that Hial are looking at Stornoway and Benbecula airports as burdens rather than assets."