British Airways A321 at Amman on Aug 23rd 2014, could not retract nose gear

A British Airways Airbus A321-200, registration G-MEDL performing flight BA-146 from Amman (Jordan) to London Heathrow,EN (UK), was climbing out of Amman when the nose gear could not retracted. The aircraft levelled off at 8000 feet, the crew worked the related checklists, descended the aircraft to 6000 feet to burn off fuel and returned to Amman for a safe landing about 3 hours after departure.

A ground observer reported the main gear of the aircraft was retracted shortly after takeoff, the nose gear however remained extended all time.