• Two passengers engaged in "intimate acts" on a Swiss International flight from Bangkok to Zurich.
• A flight crew member took a video of the incident from a monitor in the cockpit.
• Swiss said the crew should have intervened immediately, and that it was investigating.

Airline crew members are under investigation after a video of two passengers on a Swiss International Air Lines flight emerged on social media.

The incident took place last Friday on a flight from Bangkok and Zurich, an airline spokesperson told Business Insider.

The spokesperson said two passengers were in the front galley of the Boeing 777 near the flight deck, where a camera is located that lets pilots carry out checks before opening the cockpit door.

From a screen on the flight deck, the couple were "observed engaging in intimate acts" while a crew member recorded them on a phone.

Footage of the couple then began circulating on WhatsApp and was obtained by the Swiss newspaper 20 Minuten, which first reported the story.

The airline said it expected the crew to intervene immediately and found it "intolerable" that the passengers were filmed and commented on instead. Disciplinary action against the crew members was being considered.

"Filming people without their clear consent and sharing these recordings is contrary to our guidelines and values," the Swiss spokesperson said.

"The behavior of the passengers in question was inappropriate — therefore, our employees should have acted in line with our protocols and intervened immediately," they added. "Why the crew did not act accordingly is the subject of the ongoing investigation."

Among other things, the airline plans to increase employee education and training on such topics to help avoid similar incidents in the future.

• A KLM Boeing 777 flying from the Netherlands to South America turned around over the Atlantic Ocean.
• The passengers were traveling to the small nation of Suriname but ended up back in Amsterdam.
• Diverting back to an airline's hub can make it simpler to reroute passengers or make repairs.

A KLM plane U-turned over the Atlantic Ocean, leaving passengers with a four-hour flight to nowhere.

The Boeing 777 left Amsterdam for Paramaribo, the capital of the small South American nation of Suriname, on Sunday.

Data from Flightradar24 shows the flight departed on time. But two hours into the journey and about 900 nautical miles from Amsterdam, the Boeing 777 turned around over the ocean and headed back.

It landed back at Amsterdam's Schiphol Airport about four hours after takeoff. The flight to Suriname, which was once a Dutch colony and still uses Dutch as an official language, typically takes just under nine hours.

The Aviation Herald, which first reported the incident, said the pilots told air traffic control the plane had a small leak, but it wasn't clear what type.

A KLM spokesperson told Business Insider there was a "technical malfunction," adding, "As a precaution, the aircraft returned after two hours of flying."

Passengers flew on a replacement aircraft about eight hours after the scheduled departure time.

The 777 was back in service the following day, according to Flightradar24.

It's not the first time passengers have been left with a flight to nowhere in recent weeks.

Last month, an American Airlines flight encountered turbulence on the way from Brazil to Miami. It turned back to São Paulo, and one passenger was taken to hospital.

In late October, a British Airways Boeing 777 experienced a problem over the Atlantic. It turned back to London and landed there nine hours after takeoff.

For carriers flying over the Atlantic, a flight to nowhere is often the best decision when something goes wrong. It's typically simpler for airlines to reroute passengers and fix planes back at their hub airports.

But sometimes diversions to non-hub airports are unavoidable. In May, for instance, an Air France jet made an urgent landing in Canada's far north, causing a different flight to be canceled to rescue the passengers.