It is understood the pilot reported problems with the hydraulics system.
The issue was reported within minutes of the plane taking off from Belfast International Airport.
The plane has now landed safely.

The cause of the blaze at The Football Factory on Avondale Industrial Estate, Cwmbran, is not yet known.
South Wales Fire and Rescue Service received a call-out shortly before 18:50 GMT on Saturday.
At the height of the fire, six fire engines and three water bowsers were called to the scene. Fire crews spent Sunday afternoon damping down.
Staff at The Football Factory, an indoor sports facility with training pitches and a bar, said they were "devastated and heartbroken".
In a post to customers on Twitter, staff said: "Due to a large fire at the Football Factory premises, we regret to inform you that we will be closed for the foreseeable future.
"Many thanks to all of our loyal customers and we apologise profusely for any inconvenience to people who have booked with us in the future. Anyone with future bookings/paid deposits etc will be contacted in due time.
"All of us at the Football Factory are devastated and heartbroken over this horrific incident."
A United Airlines flight from Belfast to Newark has been diverted to Manchester Airport.
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Owners of an indoor sports facility in Torfaen have been left "heartbroken" after a large fire at their business.