Several equipment outages over the past two weeks at the Philadelphia-based air traffic control center that guides planes to and from Newark Liberty International Airport have raised concerns about how safe it is to fly at one of the nation’s busiest airports.

United Airlines executives are trying to reassure their customers it is safe to fly at Newark Liberty International Airport, despite widespread cancellations and air traffic control issues continuing to spark concerns.

Should Newark Airport close until air traffic control upgrades are made? Experts and officials debate safety and the economic impact.