Nearly 200 passengers on a Qantas flight across Australia had an “unsettling experience” on Monday after a mid-flight emergency.

QF643 had departed Sydney on minutes before, bound for Perth, when the pilot reported smoke in the cockpit.

Urgent access was requested to land back in Sydney about 8.45am.

The Boeing 737 then circled the airport before being cleared for a priority landing and returning to its gate. It was met by emergency services as the plane’s rattled passengers were disembarked.

“Our pilots are highly trained to handle situations like this and the aircraft landed safely after the appropriate procedures were conducted,” a Qantas spokesperson said.

“We understand this would have been an unsettling experience for customers and apologise for the inconvenience.”

It is understood there was no smoke in the plane’s cabin.

Qantas said it would investigate the incident onboard the Boeing 737.

Passengers were transferred onto a new flight that departed Sydney at 11.30am.

Qantas’s 737’s generally have a capacity for 174 passengers and several more crew.

Monday’s incident follows another Qantas emergency at Sydney airport in November.

Qantas flight QF520, a Boeing 737-838, had just departed for Brisbane when passengers reported hearing a loud bang.

“We knew immediately something was wrong. But what was more disturbing, I think, the plane really laboured after that,” ABC reporter Mark Willacy, who was among those onboard, said at the time.

The plane banked and looped over Sydney for about 15 minutes before eventually landing safely. However, it’s landing coincided with a grass fire along the eastern side of one of the airport’s runways.

“As we were coming in, it was clear that there was some sort of fire on the runway,” Willacy said.

“There was … a lot of smoke, a lot of fire engines … Eventually we had to make a very efficient exit from the plane because the right engine was still leaking some sort of fluid.”

Qantas said at the time it suspected engine failure was behind the incident.