The first of Australia's next-generation fighter jets have touched down at their new home base at Williamtown, north of Newcastle in New South Wales.

Key points: A total of 72 of the US-built aircraft have been ordered

A total of 72 of the US-built aircraft have been ordered Defence Minister Christopher Pyne said each plane cost $124 million

Defence Minister Christopher Pyne said each plane cost $124 million Pyne said Australia ranked 12th in world for amount spent on defence

The two F-35A Joint Strike Fighters conducted a flyover along the coastline of the Hunter region accompanied by four F/A-18A/B Hornets, the ageing aircraft they will be replacing.

A total of 72 of the US-built aircraft have been ordered and will continue to be delivered to Australia over the coming years.

It is expected 56 will ultimately be based at Williamtown RAAF base and 16 at Tindal in the Northern Territory.

Defence Minister Christopher Pyne said each plane cost $124 million and represented good value for money.

"This is the largest acquisition of the Air Force's history, $17 billion, and arguably the most lethal acquisition in the Air Force's history, certainly of its time," Mr Pyne said.

"The cost [of the Joint Strike Fighters] has dropped by 3 to 4 per cent every year for the last 11 years.

"The next batch will be below $100 million and continuing to fall — we regard that as value for money because we place a very high value on the capability of Australians to win in theatres [of war] and also for our servicemen and women to return home alive."

Mr Pyne said Australia was ranked 12th in the world for the amount of money it spent on defence, which he said was important to maintain Australia's standing as a "first-world military nation".

"It matters to the national interest that Australia has the most capable air force in the region, that we have the regional superior air force capability and the F-35A gives us that capability," he said.

"The F-35A … changes the way we conceive of a battlefield. It connects all of the different platforms on the battlefield whether they are at sea, on land or in the air to determine the best way, the most efficient and effective means to taking out an opponent — that makes it the most lethal platform in the air, but it also increases the lethality of all the other platforms."

Each of the F-35A Joint Strike Fighters cost $124 million. ( ABC Newcastle: Ben Millington )

The chief of the Air Force, Air Marshal Leo Davies, said the new fighter jets would radically change the way Australia engaged an enemy.

"The F-35 has an ability to see the battle space and translate that into a way that gives other folk a picture of what the battle space is," he said.

"So we can choose to put the right effect in the right space at the right time.

"It is very much now … the conductor of an orchestra, not just a single instrument."

He said the Air Force would take delivery of two new F-35As "every few months" to achieve a total of eight planes by the end of 2019 and 30 or 31 by the end of 2020.