Jet fuel costs have rocketed amid a global shortage caused by conflict in the Middle East Get Travel Insider with Simon Calder. A newsletter packed with tips, deals, inspiration, and the latest travel news Get the Travel Insider newsletter with Simon Calder Get the Travel Insider newsletter with Simon Calder Email * SIGN UP I would like to be emailed about offers, events and updates from The Independent. Read our Privacy notice Budget airline Spirit Airlines is reportedly on the verge of