Cathay Pacific A350 Intercepted by NATO Jets After Radio Silence Over Europe

On July 4, Cathay Pacific flight CX-257, an Airbus A350-1000 carrying up to 334 passengers, encountered a serious in-flight communication issue while en route from Hong Kong to London Heathrow. After departing Hong Kong at around 8:40 am local time, the long-haul flight was proceeding on a 13-hour, 40-minute journey that navigated around Russian airspace to reach Europe. During passage through Romanian airspace at 38,000 feet, Air Traffic Controllers (ATC) lost radio contact with the flight's cockpit, unable to reach the pilots despite repeated attempts over the designated frequency.

The loss of communication persisted as the aircraft crossed into Hungarian airspace without notifying the responsible ATC unit. This breach of standard protocol escalated security concerns and triggered a potential alert. In response, NATO scrambled fighter jets to intercept the flight and assess the situation directly. The jets visually approached the Airbus A350-1000, signaling the need for pilot attention via established visual warning measures. Shortly thereafter, the flight crew reestablished radio contact, confirming no emergency conditions aboard the aircraft.

With communication restored, the NATO fighter jets were quickly stood down, and Cathay Pacific CX-257 was allowed to proceed safely to London Heathrow. While the immediate crisis was resolved without incident, questions remain as to why the radio silence occurred initially. Hong Kong's Civil Aviation Department has instructed Cathay Pacific to conduct a thorough investigation and produce a detailed report within one week of the incident.

Cathay Pacific confirmed a comprehensive review is underway, including meetings with relevant flight crew. One possible explanation under consideration is a malfunction in the aircraft's radio system, although this is viewed as less likely given communications resumed almost immediately following jet interception. Another scenario being examined is whether the pilots inadvertently selected the wrong radio frequency, causing the loss of contact with ATC.

Some commentators have floated the possibility that fatigue may have played a role, with the suggestion that both pilots could have fallen asleep during the ultralong-haul flight. Cathay Pacific typically crews flights to Europe from Hong Kong with at least four pilots, allowing two to rest while two remain on duty. The regulatory framework also permits controlled rest — a short nap for one pilot while another monitors the flight — designed to mitigate fatigue risk, particularly during late flight stages.

In Europe, controlled rest periods are strictly limited to 45 minutes plus a 20-minute recovery phase, intended to prevent deep sleep and ensure prompt pilot responsiveness. European Aviation Safety Agency research indicates such rest can significantly improve pilot alertness near descent and landing phases. Contrastingly, the U.S. Federal Aviation Administration does not permit controlled rest, favoring alternative fatigue management strategies.

Despite these considerations, Cathay Pacific reaffirmed the flight followed its authorized route for the entire journey. The incident evokes parallels to a 2022 case involving Ethiopian Airlines, in which both pilots reportedly fell asleep on a flight from Khartoum to Addis Ababa, overshooting their destination and triggering onboard alarms when autopilot disconnected. Such cases highlight ongoing challenges in balancing crew rest with operational vigilance on long-haul flights.