They usually strive to please passengers.

But a team of AirAsia cabin crew decided to ditch their professionalism in favour of a bizarre plane prank, instead.

Footage shows staff taking part in a strange 'moaning' competition over the commercial craft's PA system, while bemused travellers look on, reports Daily Mail.

The exercise, which took place as the plane flew over the South China Sea, appears to have involved the crew and willing passengers trying to moan into the PA system for as long as they possibly can, until their breath runs out, with prizes awarded for the loudest, longest moan.

Advertisement

At one point a staff member announces that someone managed to emit an 80-second moan, which she appears to find rather amusing.

Some passengers find the episode quite funny, but not all onboard gave the prank the thumbs up.

The footage was filmed and uploaded online by a couple from Chicago, Harry and Audrey Lesner, who run a travel website called thebudgetsavvytravelers.com - and they definitely weren't impressed.

Harry said: "As if flying isn't stressful enough these days! Consider this unimaginable scenario.

"The captain announces that the aircraft has reached cruising altitude. Passengers begin to settle in and eyes become heavy. Next, the unthinkable happens.

"The flight crew decides to hold a moaning contest aboard your flight.

"We caught this mind-boggling moment while flying from Kuala Lumpur, Malaysia, to Cebu, Philippines."

He added: "The reaction of the passengers was priceless. It was a mix of shocked mutual stares, bulging eyes and covered ears, and confused 'what the hells?' It lasted around 10 to 15 minutes as there weren't many eager participants."

The footage was filmed in January but only recently emerged.

Audrey, sitting next to someone who's decided to use his earphones to escape the cacophony, explains to the camera that the staff are making the noises "as part of a game for the Chinese New Year".

The couple said that the experience hadn't put them off flying with AirAsia.

MailOnline has contacted AirAsia for a comment, but is yet to receive a response.