Two captains of Cathay Pacific Airways lost sight during two separate flights, according to the Hong Kong Civil Aviation Department. In both cases, the first officer managed to land the aircraft safely.

The latest incident happened on February 21, 2019, when the captain on Cathay Pacific CX170 flight between Perth, Australia, and Hong Kong told the first officer that he was feeling short of breath and that his vision was becoming weak.

The first officer took command of the aircraft, and a senior flight attendant was called in the cockpit to assist in the aircraft operation. The Airbus A350, registered B-LRR, was carrying 270 passengers and 13 crew members.

One of the passengers, a medical professional, administered first aid to the captain and provided him with oxygen to stabilize his condition, according to a preliminary report by the Civil Aviation Department. A company doctor, reached by satellite phone, assisted the passenger. The captain remained conscious during the whole incident.

The first officer requested a priority approach to Hong Kong air traffic control and lowered the altitude of the flight to reduce cabin pressure, helping the captain recover. The plane was met with emergency services upon landing in Hong Kong International Airport.

A month earlier, on 26 January, another Cathay Pacific captain of flight CX583 between Sapporo, Japan, and Hong Kong gave control of the aircraft to his first officer after suffering a sudden loss of vision.

The captain harnessed himself to his seat to “to prevent any possible interruption with the operation of the aircraft,” is stated in a report. Conscious during the whole incident, he instructed the in-flight service manager to contact medical advisory services for immediate medical assistance, and the first officer to warn the operator’s Integrated Operations Centre (IOC) of his incapacitation.

The Boeing 777-300, registered B-HNP, was carrying 348 passengers and 16 crew members. After priority approach, it landed safely in Hong Kong International Airport.

The two incidents were classified as “serious incidents”. Both investigations should take about a year. While for now, nothing can say that they were related, such a sudden loss of vision was described as “a rare incident” by Hong Kongese pilot and lawmaker Jeremy Jansen Tam Man-ho, quoted by the South China Morning Post.

On January 28, 2016, a pilot of the British Royal Air Force had lost sight during a training flight in a Hawk jet in North Yorkshire. Another jet had been scrambled with an instructor on board that helped the impaired pilot to land at RAF Leeming air base. Sources quoted by the Telegraph had said at the time that his vision was affected by the sudden deterioration of an eye infection.