A RAF Hawk training aircraft declared an unspecified emergency at 2:35pm, redirecting to RAF Shawbury.
The plane passed south of Llangollen, over Gobowen and Ellesmere as it redirected to RAF Shawbury just north of Shrewsbury, believed to have been suffering issues with its right hand engine.
The British Aerospace Hawk T2 appears to be one of a pair flying out of RAF Valley this lunchtime conducting normal training through the mountains of North Wales.
The other aircraft appeared to continue maneuvers.
The above plot is from our own data giving a more granular update, with the below from a wider public tracker:
Top picture: By Pete from Liverpool, UK (Hawk at RAF Valley) CC BY 2.0 (http://creativecommons.org/licenses/by/2.0), via Wikimedia Commons.