Experts warn of excruciating travel plans on airlines this summer. Over 800 flights were canceled in the US Monday, June 27th, followed by 1,500 flights canceled over the weekend. Airlines have fewer pilots and employees since before the pandemic, despite $54 billion in federal aid to help avoid involuntary layoffs. As a result, operations can quickly fall apart when there’s bad weather, understaffed air traffic control centers and sick staff.