A Ryanair flight to London Stansted has been forced to return to George Best Belfast City Airport.
The decision was taken after cabin crew noticed an "acrid smell" in the cabin shortly after take off.
The 7.10am Tuesday flight turned back and landed normally at 7.30am according to a statement.
Passenger Andy Patterson said: "There was a slight delay before the flight as they were checking out the engines.
"Slightly after take-off there was a distinct smell of fumes in the cabin. A short while later the pilot came over the tannoy and said we would return to Belfast as a precautionary measure," he added.
The statement said:: "All passengers disembarked normally using the aircraft steps. Ryanair engineers will now examine the aircraft, before releasing it to return to service later this morning."