Tiger plane flew too low at Avalon
An interim report confirms that a Tiger Airways plane flew too low without clearance at Avalon Airport last month.
THE descent by a Tiger Airways flight at low altitude into Avalon airport, near Geelong - the incident that triggered the grounding of the airline - did not represent a serious threat to the aircraft or passengers, the head of the Australian Transport Safety Bureau has told the Herald.
''There's a substantial safety buffer built into the minimum safe altitude arrangements, which means there was no serious threat to the safety of the aircraft,'' said the ATSB chief commissioner Martin Dolan.
In the release of its preliminary report into the June 30 Avalon incident, the ATSB reveals controllers twice queried - but accepted without challenge or instruction to the contrary - the pilots' low altitude.
Trouble started for the pilots of Tiger flight 6207 after an aborted landing due to a higher-than-expected tailwind, where pilots powered back into the sky.
The ground controller advised the pilots to climb to 3000 feet, which they did, and then the pilots advised controllers they would perform a tear-drop shaped U-turn for the second landing approach, which the controller approved.
''The aircraft left its assigned altitude of 3000 feet without an airways clearance,'' the investigators found.
It then descended to 1600 feet, ''which was below the minimum safe altitude for that area of 2000 feet,'' the investigators found.
At both moments, the plane was 400 feet too low - first at 2600 feet and, then, at 1600 feet.
But the bureau's edited transcript of the radio interchange between the pilots and air traffic controllers reveals the controllers twice queried, but didn't quibble with, the pilots' low altitude.
The plane descended further and levelled off at 1600 feet (400 feet below the official minimum), which is queried by the controller: ''Are you happy with the terrain there, you are showing one thousand six hundred [feet]?'', to which the pilots responded ''Yeh, … affirm, we are visual [meaning the pilots can see the runway and navigation marks].''
The controller responded: ''OK thanks.''
When the Herald asked Mr Dolan whether the controllers could have been clearer in whether they were - or weren't - granting clearance for the rate of descent, he said: ''You can take the information we have out there and form that view if you wish.''
The action of air traffic control is as much a focus of the investigation as the pilots, he said.