An aeroplane was forced to circle for more than half an hour after an air traffic controller dozed off. The pilot of the cargo plane said he attempted a number of times to contact the controller for permission to land – but got no answer.

He was forced to circle Nice Airport in France until the sleepy controller was woken up by security officials more than 30 minutes later. French air traffic control service DGAC described the case as ‘extremely rare’ and said the cargo plane ‘had never been in difficulty’.

An internal investigation has now been set up to discover why the controller fell asleep on the job.

(Adapted from www.flightglobal.com)

GLOSSARY
dozed off – adormeceu

The verb “discover”, in the text, is closest in meaning to