Tiger flight flew low without clearance

The pilots of a Tiger Airways flight flew at an unsafe low altitude without permission as they came in to land at Avalon Airport last month.

The incident on June 30 was the final straw for the Civil Aviation Safety Authority (CASA) which grounded the entire Tiger domestic fleet the following day after previously putting the airline on notice over pilot proficiency and aircraft maintenance issues.

After originally being grounded for a week, Tiger's domestic flights are now out of action until at least August 1.

A preliminary investigation report by the Australian Transport Safety Bureau (ATSB) released today found that, after missing its first approach, the crew was directed to climb to 3000 feet and reposition to land on a different runway.

"During that repositioning, the flight crew left the assigned altitude without clearance and descended to 1600 feet, which was below the minimum safe altitude for that area of 2000 feet," the report found.

The investigation is continuing and will analyse recorded flight and air traffic control data and examine the pilots' procedures.

An earlier investigation into a Tiger landing at Melbourne Airport on June 7 found the flight approached at 2000 feet, instead of the minimum 2500 feet, because of an incorrect lowest descent altitude in the commercial navigational database.

The same pilot was in control of the two Tiger flights that led to the grounding of the entire airline.

Australian Federation of Air Pilots industrial relations manager Lawrie Cox said earlier this week the experienced pilot was the captain of both flights.