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.

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

Moving air traffic controllers means retraining them on the quirks of a new facility, and the process can take years.