One simple mistake of getting a plane’s position wrong on the tarmac has caused a Sydney flight to Malaysia to be diverted to Melbourne, investigators say.

The captain of an AirAsia X flight on March 10, 2015, inadvertently entered the wrong longitudinal position of the aircraft before take-off, causing the on-board navigation system to go into a spin while in the air.

The crew’s attempts to fix the problem didn’t help, the Australian Transport Safety Bureau (ATSB) said on Wednesday.

“Attempts to troubleshoot and rectify the problem resulted in further degradation of the navigation system, as well as to the aircraft’s flight guidance and flight control systems,” the ATSB said.

The plane had to be diverted to Melbourne with navigational guidance because of deteriorating conditions in Sydney.

The ATSB also found that the aircraft was not fitted with an upgraded flight management system that would have prevented the data entry error.

In handing down the report, the ATSB recommended equipment be upgraded and further training be offered to crew.

“This occurrence highlights that even experienced flight crew are not immune from data entry errors,” the ATSB said.

“However, carrying out procedures and incorporating equipment upgrades recommended by aircraft manufacturers will assist in preventing or detecting such errors.”

AirAsia has developed a training bulletin and package for its flight crew in response to the investigation’s findings.

-AAP