The chief executive of Heathrow has defended the running of the airport after a fire at an electrical substation stopped about 1,300 planes and disrupted the journeys of hundreds of thousands of global passengers. It comes after Willie Walsh, the International Air Transport Association’s director general, criticised Heathrow for the disruption, while the energy secretary, Ed Miliband, has now ordered the National Energy System Operator to “urgently investigate” the outage. The Department for Energy Security and Net Zero said the “investigation will support efforts to build a clear picture of the circumstances surrounding this incident and the UK’s energy resilience