On Sunday 15 passengers were removed from a Swiss flight to Geneva after the plane was deemed too heavy to take off. Airlines have admitted it is a recurring problem that has been exacerbated by the recent heat wave.
London City's single 4,900-foot runway is one of the smallest in the country, meaning many larger aircraft models cannot use it. By comparison Gatwick's two runways are 8,415 feet and 10,879 feet and Heathrow's are 12,008 feet 12,799 feet.
In hot weather it often takes longer for a plane to take off, meaning – as was the case on Sunday – passengers may need to be offloaded to reduce the aircraft's weight.