The circumstances behind the grounding of U.S. air traffic, prompting thousands of cancelled flights around the world, are being called by an aviation analyst “disturbing.” The loss of both voice communication and surveillance data during routine maintenance of an aging telecommunications system is something the industry will learn from, former flight controls engineer Peter Lemme told CTV News Channel Saturday. Faulty equipment in an “incredibly old” telecommunication system may have caused an air traffic control issue, U.S. Transportation Secretary Sean Duffy said earlier in the day. Per Duffy, a contractor was doing routine maintenance to upgrade copper wire to fibre optic cable when something went wrong. The issues is under investigation, and U.S. air travel is expected to return to normal by the end of the day on Sunday, according to American officials -- an estimate some experts suggested could not be guaranteed. The ripple effects of the hours-long freeze have been felt by Canadian travellers at airports across the country as they deal with flight delays and cancellations. Here were the key updates on Saturday:
