US air traffic control chief quits

The head of the US air traffic control agency has resigned after a number of incidents where air traffic controllers fell asleep while on duty.

Randy Babbitt, chief of the Federal Aviation Administration, said he had accepted Hank Krakowski's resignation.

On Thursday, Mr Babbitt pledged a "top to bottom review" of the air traffic control system.

In the past month, several planes have landed safely at US airports without controller guidance. The BBC's Tim Neilson reports.