On a multi-engined aeroplane if any engine fails the the a/c will roll to the dead engine side. The natural response is to roll level again, telling you which side the 'dud' engine is on. Sort yourself out and then decide what you can do or want to do. 'Simples' as the tv add says. Learnt this lesson from a Boeing Test Pilot on a LHR - Sea flight when on 747s many years ago.