EMERGENCY services were alerted on Thursday morning after a Sikorsky S-92A helicopter destined for Sumburgh Airport raised the alarm.
The Babcock helicopter, which had 21 people on board, landed safely just after 10.30am.
Scottish Fire and Rescue Services sent three appliances towards the airport, while the Lerwick Lifeboat was also tasked before being stood down while it was near Mousa.
A spokesperson for airport operator HIAL said: “At 9.49am Sumburgh Airport emergency services were mobilised for the arrival of a helicopter.
“The aircraft landed safely at 10.31am and the emergency was stood down.”
It comes a day after an emergency was declared at Sumburgh when a Bristow helicopter reported a warning light before landing safely.