Hong Kong(CNN) The crew of a Cathay Pacific flight from San Francisco to Hong Kong saw what they believed was a North Korean ballistic missile re-entering the Earth's atmosphere last Wednesday, the airline said Monday.
Cathay said in a statement that it had been in contact with relevant authorities, industry bodies and other airlines about what was seen from Cathay Pacific flight 893, and at the moment there were no plans to change flight routes.
"Though the flight was far from the event location, the crew advised Japan ATC (Air Traffic Control) according to procedures. Operation remained normal and was not affected," the statement said.
"We remain alert and review the situation as it evolves."
North Korea fired what is believed to be the biggest and most powerful missile in its arsenal last Wednesday, the Hwasong-15, after a weeks-long lull in testing.
United States Defense Secretary James Mattis said shortly after the missile was launched that the missile demonstrated North Korea may have the ability to hit "everywhere in the world."
The Hwasong-15 flew 4,475 kilometers (2,800 miles) in the sky, spending 53 minutes in the air, before splashing down in waters off the coast of Japan, North Korea said. The figures tallied with estimates released by Japan and South Korea.
Cathay said it does not have images of video of the incident. Many of the carrier's international flights have a camera mounted beneath the fuselage, which passengers can view live from their seats. Cathay did not respond when asked by CNN if that video is recorded and saved.
It's not the first time this year a North Korean missile has had a close call with a passenger plane.
On July 28, an Air France flight passed just east of the splashdown site of a missile test, roughly five to 10 minutes before the weapon hit the water. At the time of the splashdown, the flight was about 60 to 70 miles (95 to 112 kilometers) north of where the missile landed, according to a review of the data.
At the time, US Defense Department spokesman Jeff Davis warned the intercontinental ballistic missile North Korea tested in July "flew through busy airspace used by commercial airliners."
Guidelines issued by the International Civil Aviation Organization, a UN agency tasked with governing air safety and other matters, state that nations have the "responsibility to issue risk advisories regarding any threats to the safety of civilian aircraft operating in their airspace."
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South Korea said its northern neighbor regularly fails to issue notices to airmen (NOTAM) when conducting missile launches. Such notices are issued to warn pilots and airlines of potential risks during their flights.
The chance of an unaimed missile striking a plane are "billions to one," according to CNN aviation safety analyst David Soucie.
But if a ballistic missile were to come close to a passenger jet, it would be nearly impossible for the crew to detect, a Hong Kong-based pilot told CNN in August in the aftermath of that missile test.
"You wouldn't even know it was coming," he said, speaking anonymously as he was not authorized by his employer to discuss sensitive matters.