Plane takes off without air traffic control clearance
Edinburgh-bound flight departed from Kirkwall Airport in Orkney amid dispute over pay.
A plane departed from Orkney without air traffic control clearance amid a staff pay dispute.
The Loganair flight from Kirkwall Airport to Edinburgh - carrying 33 passengers and three crew members - was scheduled to depart at 7.35pm on Friday.
However at 7.43pm, it was denied start-up clearance.
The aircraft then used "alternative procedures" to take off, including utilising the help of the airport's fire and rescue service to operate the runway lights.
Loganair and Highland and Islands Airports Limited (HIAL) told STV News that safety was not compromised and the flight eventually proceeded as planned at 8.45pm.
The incident took place amid a pay dispute between HIAL and Prospect union members.
The workers have taken action short of a strike, which includes working to rosters, the refusal of non-medical extensions, an overtime ban and the withdrawal of goodwill.
On Tuesday, the union announced that a planned strike for April 26 had been called off due to "productive" discussions through conciliation service ACAS.
Loganair believes safety staff should have been available until 8.30pm, "to accommodate eventualities such as an aircraft departing but then needing to return after take-off in an emergency".
However, the union has argued that start-up clearance was denied as it would have involved a controller having to work beyond their shift - contravening "very strict" rest periods.
Jonathan Hinkles, Loganair's managing director and accountable manager, said: "We believe that Friday evening's actions by air traffic control staff at Kirkwall were beyond the scope of the dispute notified by Prospect.
"It is a matter of profound regret that HIAL's air traffic controllers - a group whom we hold in the highest professional regard - have chosen to engage in this action based on their union's advice, and moreover have exceeded the legal scope of action in doing so.
"This introduces unnecessary pressure for everyone into an operational environment where safety is paramount.
"We are calling on Prospect to ensure its members act within the law; and on HIAL and the cabinet secretary for transport to take action against Prospect to ensure that its right to engage in industrial action is exercised only lawfully.
"All indications available to us are that this was not the case in Kirkwall on Friday evening.
"We would like to thank the HIAL safety teams and Loganair's crew for their efforts to ensure that our customers were able to safely enjoy their planned flight to Edinburgh despite this unforeseen and unnecessary turn of events in the HIAL and Prospect dispute."
'We understand there is an ongoing investigation into the incident and the Civil Aviation Authority have been informed. It would be wrong to get into too much specific detail on the incident while that investigation is ongoing'David Avery, Prospect negotiations officer
In response, David Avery, Prospect negotiations officer, said the union's industrial action was instigated and carried out legally.
He said: "Even without the work to rule, if a flight wants to depart outside the airport's opening hours, an extension would be voluntary and could not be guaranteed."
He added: "The rules relating to rest periods for air traffic controllers are very strict.
"Due to these rules the controller had to come off the desk at 8pm and there is a requirement that the last departure is 15 minutes before the close to ensure that an aircraft can return if there is a problem during take-off.
"Loganair had been informed that the last departure time was 7.45pm. It takes ten minutes from start-up clearance to departure."
An investigation has now been launched by Highlands and Islands Airport Limited.
A HIAL spokesperson said: "HIAL is investigating the circumstances that resulted in Loganair flight 394 from Kirkwall to Edinburgh being unable to depart during airport opening hours on Friday, April 5.
"The flight was able to depart following a dynamic risk assessment undertaken by Loganair's flight operations management in conjunction with HIAL.
"Recognised safety procedures were followed before the aircraft departed safely and completed its schedule to Edinburgh."
The UK Civil Aviation Authority (CAA) has also been informed.
A spokesperson said: "We are aware of an incident involving a flight departing from Kirkwall Airport on Friday, April 5 and are currently looking into the circumstances."