“A faulty app caused American Airlines to ground dozens of its jets on Tuesday. The glitch caused iPad software, used by the planes’ pilots and co-pilots to view flight plans, to stop working. The firm’s cockpits went ‘paperless’ in 2013 to save its staff having to lug heavy paperwork on board. AA estimated the move would save it more than $1.2m (£422,770) in fuel every year.”
Source: American Airlines planes grounded by iPad app error – BBC News