Angus residents have reported hearing a sonic boom after a fighter jet passed over the area.
The sound was reported in both Arbroath and Brechin on Wednesday afternoon.
A sonic boom is often compared to a loud crack of thunder and is produced when an aircraft goes supersonic.
At sea level, 761mph is the speed of sound.
RAF Lossiemouth later confirmed that two Typhoon jets were “scrambled” from the air base in Moray after a civilian aircraft failed to make contact with air traffic control.
In a statement, the RAF base added: “Communications between the aircraft and ATC were re-established and no further action was required.”
UK aviation law requires supersonic flights to take place over the sea, unless it is “operationally required”.
‘Rattled windows’ in Arbroath and Brechin
Residents in both Arbroath and Brechin reported rattling windows and feeling their houses shake at the time of the sonic boom.
Arbroath resident Richie Bell told The Courier the noise had woken his young grandson and that it had been “heard all over town”.
“It rattled my windows and a door blew in”, he added.
A flight-tracking website appeared to show the jet had originated near RAF Lossiemouth.
It had travelled on a south-east trajectory towards the Angus coastline and then performed several loops above the North Sea.
An aircraft can produce a sonic boom when it flies at a speed faster than or equal to the speed of sound.
NASA estimates the speed of sound is around 761 mph when recorded in the atmosphere on a “standard day”.
The Ministry of Defence has been approached for comment.
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