Military jets were scrambled to escort a passenger plane which was forced to make an emergency landing at Prestwick Airport.
The RAF said the Typhoon jets were sent at "supersonic speed" in reaction to an "unresponsive civilian aircraft".
The alert was raised when the plane lost communications at around 2.40pm on Friday.
The Typhoons escorted the aircraft to the Ayrshire airport, which declared a full emergency response with police closing surrounding roads.
The plane, which is understood to have been en route to Iceland, landed safely and an investigation is being carried out into the loss of communications.
Members of the public reported hearing a sonic boom as the jets passed overhead.
The roads surrounding the airport were later reopened.
An RAF spokesman said: "Quick reaction alert Typhoon aircraft were launched today from RAF Coningsby and RAF Lossiemouth to identify an unresponsive civilian aircraft.
"The Typhoon aircraft were authorised to transit at supersonic speed for operational reasons, any inconvenience caused to local residents is regretted.
"Communications were re-established and the aircraft has been safely escorted by the Lossiemouth aircraft to Prestwick Airport."
A Police Scotland spokeswoman said: "An aircraft has been escorted to Glasgow Prestwick at around 2.40pm following reports of a temporary loss of communications.
"A full emergency response has been put into action the airport and the aircraft landed safely at 3.57pm.
"The emergency services are still in attendance to establish the full circumstances."