Several times over the last year, Newark controllers lost radar or radio service, leaving them unable to talk with planes they were tracking.

A deadly midair collision in January between a military helicopter and a commercial airliner, and several crashes since, have prompted officials to focus on fixing the nation’s outdated air traffic control system and hiring more controllers.

US air safety regulators said they will upgrade equipment guiding flights into Newark Liberty International Airport after a reported radar and radio communications shutdown, endangering travellers and crew flying into the busy hub.