A graduate in German, Jake has a passion for history and regional aviation, and enjoys sampling new carriers and aircraft. He has visited OEM facilities as far and wide as Bristol, Toulouse, and Seattle, and recently enjoyed the milestone of flying his 150th sector as a passenger. Based in Norfolk, UK.
A Singapore Airlines Airbus A350-900 flying from 
San Francisco International Airport (SFO) to Singapore Changi Airport (SIN) had to return to the Bay Area on Wednesday after a disruptive passenger caused an onboard disturbance. He reportedly injured himself in the process, and was arrested once the aircraft had arrived back in San Francisco after what turned out to be an eight-hour flight to nowhere.
Given the length of this sector alone, the flight's crew did not have enough hours left in their working day to undertake a second attempt at the flight. With this in mind, 
Singapore Airlines dispatched a replacement crew to fly the A350 back to its home base from California, and it eventually touched back down some 12 hours behind schedule. The ordeal was documented by a fellow passenger on Reddit.
Disruptive Disturbance Causes A Diversion
Singapore Airlines flight SQ31 is a daily transpacific service from San Francisco to Singapore. It is scheduled to take 16 hours and 25 minutes, with Flightradar24 noting that it should depart at 11:45 AM and arrive at 7:10 PM the next day. Tracking data shows that the iteration on Wednesday left just over an hour late, at 12:49 PM local time, but, as reported by One Mile At A Time, it soon got later.
This was because the acts of a disruptive passenger forced the crew to divert the flight back to San Francisco, where it landed at 8:32 PM after just under eight hours in the sky. A Reddit user on the flight, who claimed to be sitting just a few rows away, said that "three hours in, this dude started screaming, kicking seats, and even tried to get to the emergency exit." A Singapore Airlines spokesperson added that:
"A Singapore Airlines customer on board flight SQ31 (...) became unruly and injured himself in the process. The pilots assessed the situation and decided to return to San Francisco."
A New Crew Was Required For The Second Attempt
According to the Reddit user, even after being restrained, "he wouldn’t stop yelling and kicking." They added that they were "not sure if he was having a psychotic break or having a bad trip," but, either way, his day ended disastrously when, upon arrival in San Francisco, he was arrested by the FBI and local police officers who boarded the aircraft. This left Singapore Airlines in a tough spot crew-wise.
Specifically, those who had been operating the initial flight from San Francisco to Singapore now did not have enough hours left in their working day to make a second attempt at flying the transpacific route. However, The Straits Times notes that it was able to source a new crew, and it took off again after a little more than three hours on the ground, at 11:49 PM. It did so under a new flight number: SQ9031.
Having left just before midnight on Wednesday evening, the replacement flight took 16 hours and four minutes to reach Singapore, where it eventually touched down at 6:53 AM on Friday. Compared to the planned 7:10 PM arrival on Thursday night, this represented a delay of close to 12 hours. With this in mind, Singapore Airlines said that it was "rebooking connecting flights" for passengers on this service.
Singapore Airlines' Airbus A350 Fleet
The Airbus A350-900 that was operating Singapore Airlines flight SQ31 on Wednesday when it had to return to San Francisco bore the registration 9V-SJC. According to ch-aviation, this widebody twinjet is 4.36 years old, having first flown on June 7, 2022. It was then delivered to Singapore Airlines three weeks later, with 42 business class, 24 premium economy, and 187 economy class seats on board.
Singapore Airlines is a major operator of the Airbus A350-900, with ch-aviation's data showing that it currently has a grand total of 58 units of the type's standard model at its disposal. These aircraft are 7.4 years old on average, compared to a fleet-wide mean figure of 9.2. The airline famously also flies seven modified A350-900ULR jets, which it uses on its legendary nonstop flights to Newark and New York JFK.