A spy plane was found flying on an airspace monitored by the Los Angeles Air Route Traffic Control Center on Wednesday that caused a software glitch in LAX computers, resulting in delays and flight cancellations at the international airport. 

The spy plane has been identified as a U-2 similar to the high-altitude flying aircraft that embarked on covert missions to Russia more than 50 years ago. According to sources of NBCNews, the U-2 had a Defense Department flight plan and was flying at an altitude of 60,000 feet. One unnammed source called the craft by its nickname, "Dragon Lady."

The Federal Aviation Administration (FAA) decided to halt the flight traffic in the LA Center-managed airspace after computers shut down at around 2 p.m. The nationwide stop lasted for approximately one hour, and affected the flights of about 1,000 passengers.

One of the busiest airports in the nation, LAX recorded a total of 27 cancellations, 212 delays, and 27 diversions to other airports among its arriving flights. There were also 23 cancellations and 216 delays for departing flights. Lastly, delays at other airports such as Orange County, Ontario, Long Beach, Burbank, and others across the southwest also occured following the glitch.

The FAA has opened an investigation on the issue but refused to neither elaborate nor confirm if the U-2 flight directly caused the glitch.

"The FAA will fully analyze the event to resolve any underlying issues that contributed to the incident and prevent a reoccurrence," the agency said to NBCNews.

The U-2 first launched over half a century ago and was used extensively by the US airborne surveillance department. It has an operational ceiling record of a staggering 50,000 feet. Though it is still flown by the U.S Air Force, the government has already planned to retire the planes over the next couple of years.