Mainline flights connecting the major hubs were grounded for over an hour before engineers were able to solve the problem.

The airline stated in their statement, “We are working with customers to get them to their destinations after a technology disruption on Wednesday evening,” the airline said in a statement.

“The underlying technology issue has been resolved, and, while we expect residual delays, our team is working to restore our normal operations.”

The Federal Aviation Administration (FAA) in United States issued ground stops at several major airports, including Denver, Newark, Houston and Chicago.

The FAA said in a statement, “We’re aware United experienced a technology issue disrupting their operations. Some delays may continue as they work through the recovery process”.

The further stated, “We’ve offered full support to help address their flight backlog and remain in close contact with United.”

The outage adds to the series of recent challenges faced by the aviation sector. Last month, Alaska Airlines suffered IT problem that left its planes grounded for several hours.

In addition, air traffic control system of Newark airport have experienced outages multiple times this year. The issue raised concerns among many passengers.

In another incident, that occurred in January, it involved a passenger jet and a military helicopter.

The incident claimed numerous lives. These incidents have shaken passengers confidence in safety of air travel.