A Qantas plane has landed safely after issuing a mayday alert mid-air from Auckland to Sydney.

The distress call was issued after the flight suffered mechanical issues, AAP understands. It landed at Sydney Airport at about 3.30pm.

Multiple outlets are reporting the flight suffered engine failure.

NSW Ambulance confirmed its paramedics were responding to a mayday alert issued by flight QF144 from Auckland to Sydney.

FlightRadar indicated the plane, a twin-jet Boeing 737-800 travelling from Auckland to Sydney, was over the Pacific Ocean when the call was issued.

“A mayday call is an internationally recognised, emergency or distress call,” a spokeswoman for the Australian Maritime Safety Authority told AAP.

The call is issued when a flight is in grave and imminent danger and needs immediate assistance, according to Airservices Australia.

Once the call is issued controllers alert aviation rescue, firefighting and emergency services with details on how to respond. They also provide assistance to pilots.

– AAP