QF101, from Sydney to Fiji, pushed back about 8:30am and spent almost two hours circling over the NSW coast before landing again about 10:50am.

A Qantas spokesperson said the pilots followed standard procedure after receiving a “fault indicator”, and that engineers would examine the aircraft.

It is the second headache in as many days involving the airline’s fleet of Boeing 737s, after the pilot of a flight from Auckland to Sydney yesterday issued a mayday call when one of the plane’s engines failed.

In both instances, the flights landed safely.

Qantas engineers and aviation safety inspectors are set to examine tg\]he plane’s jet engine to determine why it failed on an Auckland-Sydney flight, prompting a mayday call and emergency landing.

The pilot of Qantas Flight 144, a Boeing 737 aircraft, shut down the engine and made the mayday call over the Pacific Ocean on Wednesday afternoon before landing safely at Sydney airport at about 3.30pm.

Passengers reported feeling bumps or a bit of turbulence but said they did not know a mayday had been issued until they landed. No one was hurt and passengers praised the pilot for landing the plane safely on one engine.

Qantas said that while “inflight engine shutdowns” are rare and concerning for passengers, pilots are trained “to manage them safely and aircraft are designed to fly for an extended period on one engine”.

It said all 145 passengers disembarked the aircraft normally.

Aviation expert Neil Hansford told the ABC that “Qantas has never had a passenger lost on a jet aircraft in its history”.

He said Qantas engineers would be immediately investigating what may have caused the engine failure and the Australian Transport Safety Bureau would be initiating an inquiry into the incident.

Photographs taken at the airport show one of the engines appears to have a large panel missing from the engine cover.

Passengers told reporters an engine failed but no one onboard appeared panicked during the flight.

“I kind of heard the little bang and then a bit of turbulence, and we just thought okay, this is a bit weird,” passenger Sandika McAuley said.

“But we didn’t really know anything until we landed, then we got told that there was a mayday call and the engine failed.”

Federal Transport Minister Catherine King lauded the airline’s safety record after a scare that had 100,000 people tracking the flight online.

“Well done to the highly experienced crew for getting the plane safely home,” Ms King tweeted.

“Australia’s aviation industry is among the safest in the world because of the dedicated staff working on planes and behind the scenes”.

The Australian and International Pilots Association (IAPA) said in a statement that such mid-air incidents were extremely rare and it was too early to speculate on the engine failure.

“We are pleased the expertly trained and professional Qantas pilots took all the right steps to deal with the incident and were able to safely land back in Sydney.