By Guy Taylor The aviation industry’s contribution to the economy has long been its most relied upon defence for expansion. We’re told in business circles any environmental concerns surrounding airport expansion, or airlines carrying record passenger traffic, are outweighed by the huge net positive for the UK economy. The contribution of the likes of Heathrow, Gatwick, British Airways and Easyjet are undeniably significant, with the aviation sector as a whole pumping around £12bn annually into the UK economy. But the sector’s importance for economic growth and GDP are rarely questioned. Yet, h…