MELBOURNE, Feb 10 (Bernama) –- Australian air safety investigators have found that AirAsia X pilots twice flew so low into the Gold Coast Airport that they breached the safety margin between the ground and other planes.

The Airbus A330 planes were flying from Kuala Lumpur to the Gold Coast when the incidents occurred on May 4 and May 29, 2010.

The Australian Transport Safety Bureau in a report, which classified the incident as "serious," said the jets descended to a height where there was no longer separation assurance from the ground and from planes operating outside controlled airspace.

There was low cloud and reduced visibility at the time but no reason was given for the pilots breaching the safe distance.

But investigators said the crew were "probably not adequately equipped to manage the approach in other than auto pilot managed mode."

Investigators cited a "minor safety issue" concerning the airline's training of its flight crews.

In response to the incidents, the AirAsia X has changed its flight crew procedures when conducting instrument approaches as well as modifying the simulator training programme.