Construction project on one of Newark's main runways completed ahead of schedule

NEWARK, N.J. (WPVI) -- A construction project on one of Newark Liberty International Airport's three main runways wrapped up nearly two weeks early, so the Federal Aviation Administration should be able to ease flight limits soon, but the shortage of air traffic controllers could still cause problems.

The first flights departed Monday morning, and Transportation Secretary Sean Duffy is at the airport for a news conference.

The runway, known as 4L-22R, had been completely shut down since April 15 for a $121 million routine rehabilitation and was scheduled to reopen June 15. It is now back open.

During the closure, the Port Authority had worked with United, the anchor airline at the airport, and other airlines to reduce flights during the construction. Only 28 flights were taking off and landing per hour at Newark. With this runway back open, the airport is expected to add six more per hour. Normally, 77 flights had been arriving and departing an hour there before all of the difficulties.

While Newark Airport has two other runways, the main backup could not be used in inclement weather and had been under-utilized by air traffic controllers during this period.

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The reopening is some much needed relief as Newark Airport has faced a firestorm of challenges, including staffing shortages and system outages that lead to delays and cancellations.

The FAA reduction in the flight schedule there is expected to remain in place until October 25 to ease the pressure on Air Traffic Control.

Twice in the last two months, the radar and communications systems that Philadelphia air traffic controllers who direct planes in and out of Newark rely on failed for a short time. That happened because the main line that carries the radar signal down from another FAA facility in New York failed, and the backup line didn't work immediately.

The controllers were unable to see or communicate with the planes around Newark Airport for as long as 90 seconds on April 28 and May 9.

The lines - some of which were old copper wires - failed a third time on May 11, but the backup system worked and the radar stayed online. The FAA said a fourth outage had knocked out radio communications for two seconds, but the radar stayed online.

After the initial outage, the already shorthanded control center in Philadelphia lost five to seven controllers to trauma leave. That left the airport unable to handle all the scheduled flights, leading to hundreds of cancellations and delays.

Officials have said the problems affecting the Newark airport are a prime example of why the entire air traffic control system nationwide needs to be overhauled.

Transportation Secretary Duffy announced a multibillion-dollar plan to upgrade the nation's aging air traffic control system last month.

The Associated Press contributed to this article.