Six airports have closed for 24 hours due to a strike by air traffic controllers involved in a pay dispute.
Highlands and Islands Airports Limited (Hial) said the airports at Inverness, Dundee, Benbecula and Stornoway in the Outer Hebrides, Sumburgh in Shetland, and Kirkwall in Orkney were shut on Thursday.
The Prospect union said its members did not want to take industrial action but were left with no choice after running out of patience with Hial in a dispute it says has been going on for more than a year.
Hial said it believes its air traffic controllers are well paid, adding that it has been fully committed to resolving the dispute.
In a statement issued earlier this week, Hial managing director Inglis Lyon said: “We sincerely regret this escalation of the pay dispute by Prospect members and apologise for the inconvenience that this has caused our customers.
“We continue to work closely with our airlines to mitigate the effects of strike action and I wish to thank them and all our staff who have worked extremely hard to implement contingency measures.
“Throughout this process, Hial has been fully committed to resolving this dispute.
“We are disappointed that our efforts to provide possible solutions have been rejected by Prospect and its claim has not altered and remains a wage increase of at least 10%.”
Mr Lyon said the airport operator – a public corporation wholly owned by Scottish ministers – is bound by Government pay policy and cannot negotiate a separate settlement.
The airports closed to air traffic from midnight on Wednesday until midnight on Thursday.
David Avery, Prospect negotiations officer, said: “My message to those suffering disruption to their flights is clear – ministers and Hial have the power to end this strike today and to end this disruption but are choosing not to.”
The Scottish Government said it encourages Prospect and Hial to return to discussions around a retention allowance for air traffic controllers and to work towards a resolution to the pay dispute.
A spokesman said: “We have been clear with both Hial and Prospect that any settlement must be in line with Scottish public sector pay policy.
“Hial has implemented a pay rise for all staff, which is a significant improvement on previous years, as well as significantly increasing their contribution to their pension scheme in order to maintain this benefit for employees. Staff also continue to receive generous annual leave, sick pay and other allowances.
“In the face of the UK Government’s continued budget cuts, the Scottish Government delivered a distinctive and progressive pay policy for 2018/19 – one which is fair, supports those on lower incomes and protects public sector jobs and services while delivering value for money for the people of Scotland.”