Plane carrying 280 passengers plunges 5,000 feet after co-pilot 'fiddled
with the controls' while captain was taking a nap
Incident occurred while Boeing 777-300 aircraft was en route to Brussels
Boeing analysed records of digital flight data recorder
Pilots received an emergency call from air traffic controller http://www.dailymail.co.uk/travel/travel_news/article-2760556/J
