Cracks have been found on two offshore helicopters which have been in flight for less than a year.
The Bristow operated AW189s are being repaired after concerns were raised during maintenance.
Bristow has been using the craft to transport North Sea workers flying out of Norwich.
It is understood that the operator is the first to use the craft manufactured by AgustaWestland.
A spokewoman for Bristow said: “During maintenance, non-structural fractures were discovered in a non-load bearing area of the frame.
“They are still safe to fly as the issue didn’t affect the structure of the aircraft.”
It is understood that the fault was recorded around a fortnight ago.
The spokeswoman for Bristow said the helicopters were due to return to service this week week.
Bristow took delivery of the first AW189 in July last year.
One North Sea worker said crews were now travelling in the older EC225 Super Puma models.
He said: “The EC225 I got was covered in soot and was obviously just pulled out of a shed….they didn’t even have flight safety information cards in the pockets on the back of the seats.”
Cracks found on two new North Sea helicopters – less than a year after they took flight
