How did a technical issue lead to hundreds of cancelled flights?An investigation has been launched over UK flight disruption that has left thousands of passengers stranded.Former air traffic controller, Michele Robson and operating director at Liverpool John Lennon Airport, Paul Staples, join Sima Kotecha to help us understand the system that should keep planes taking off on time.Newscasters Bex and Lydia also share their experience of cancelled flights. And, the Ultra Low Emission Zone has expanded to include all London Boroughs. Claims and counter claims are being made about the scheme's effectiveness. BBC science journalist Esme Stallard helps us get to the truth.You can join our Newscast online community here: https://tinyurl.com/newscastcommunityhereToday's Newscast was presented by Sima Kotecha. It was made by Chris Flynn with Maddie Drury and Joe Wilkinson. The technical producer was Phil Bull. The editor is Damon Rose.00:00 - Exciting Newscast news 02:27 - Inside the flight control room 16:55 - Fact checking ULEZ claims