AVALON, Australia, March 26 (Reuters) - Australia's

military will rely more on autonomous systems to overcome the

disadvantage of having to protecting vast geography, said

defence officials who predicted "friction in the system" as the

balance tipped towards uncrewed systems.

Australia's air force is working with Boeing ( BA ) to develop an

autonomous combat aircraft called Ghost Bat.

Speaking at the Australian International Air Show on

Wednesday, Chief of Air Force Stephen Chappell said the Ghost

Bat will this year demonstrate its capability and test payloads

"with the exception of it being armed", before making

recommendations to government.

"For us, autonomous platforms allow us to scale, so this is

not about replacing crewed platforms, it is about providing

greater scale and sustainability, and also increasing lethality

and effects, and increasing survivability, particularly for

crewed platforms or our defence personnel," he added.

Ninh Dong, chief of air and maritime at Australia's Defence

Science and Technology Group, said Australia had a vast

coastline and 2 million to 3 million square kilometres (772,000

to 1.2 million square miles) of northern ocean that need to be

defended, and was looking for innovations that "overcome this

asymmetric disadvantage of distance".

Autonomy and AI that are changing warfare globally will be

important, and Australia has made hypersonic missiles a

priority, Dong said.

"By holding adversaries at risk further away from Australian

shores, they give us more time to respond to threats," he said

of such missiles.

Allan Hagstrom, director of combat futures at Air Force

Headquarters, said expensive aircraft will need to integrate

with cheaper technology, and autonomous projects are already

causing "friction in the system" as defence forces reorganise.

"We are on that cusp where we are probably going to see in

the next few years, the weight of crewed platforms and uncrewed

platforms and the ratio shifting, and outnumbered by uncrewed

platforms enabled by autonomy," he said.

The challenges included how to work collaboratively with

other countries, as each nation makes decisions on the role of

humans in the "optimal solution".

"We are not talking about taking the human out of the

technological solution, but how do we leverage the human and the

machine to provide the optimal solution," he added.