Flight landing aborted due to gear failure

A Vietnam Airlines flight was about to touchdown at Melbourne Airport when air traffic controllers realised the plane's landing gear wasn't deployed.

The Boeing 787 Dreamliner was flying into Melbourne from Ho Chi Minh City when the issue was spotted at 8.04am on Thursday, according to the air safety bureau.

"During approach to land, Melbourne Air Traffic Control advised the crew that the aircraft's landing gear was observed not to be extended," the Australian Transport Safety Bureau said in a statement.

The crew initiated a "missed approach" procedure and aborted the initial landing, according to officials.

The authority will investigate the cause of the issue and will speak to the flight crew and gather any additional information as required.

"Should a critical safety issue be identified during the course of the investigation, the ATSB will immediately notify those affected and seek safety action to address the issue," it said.

A report will be released at the end of the investigation.