The Calgary Airport Authority put a third sensor into operation on Thursday that will help detect the possibility of lightning and give an advanced warning to crews. Twice already this year, lightning has grounded planes at the Calgary International Airport, stranding hundreds of passengers. The airport has a ‘lightning advisory system’ that warns when there is 'electrical activity' or the possibility of lightning strikes. The system is now being upgraded to better serve passengers at YYC. The new system features a third tower at the northern part of the airport that helps detect static electricity. It's hoped that this new tower will reduce delays for passengers. Back in June, a lightning storm grounded planes for about 24 hours, wreaking havoc for many passengers. Storms can be highly dangerous for airports because of the large number of people working near aircraft that are full of high octane jet fuel.