In contrast to Senator Reynolds, Heather Wilson, the secretary of the US Air Force in February 2019 recognised that ALIS was a costly failure. She said, "I can guarantee that no Air Force maintainer will ever name their daughter Alice". In January this year, the Pentagon announced it would scrap ALIS because it was causing operational delays of 45,000 hours a year.

Apart from maintenance and logistics, the system is used for mission planning and numerous other purposes. Although billions had been spent on developing ALIS, a US Government Accountability Office report to Congress in July said that its information was so unreliable, or missing, that crews couldn't know if a plane was safe to fly. Astonishingly, an earlier GAO report said the system's data could not be backed up.

A replacement system called ODIN (Operational Data Integrated Network) is now being developed by the F-35's manufacturer Lockheed Martin which was responsible for designing ALIS in the first place. The GAO said Pentagon officials had trouble contributing to ODIN's development because Lockheed Martin refused to share key information such as computer source code which it guards as its own intellectual property.

The new system is also likely to suffer costly faults. A report by the Congressional Research Service in May quoted a former F-35 program manager General Christopher Bodgan as saying, "Complexity of the software worries us the most ... Software development is always really, really tricky".

The F-35's cost effectiveness also suffers from a poor record in meeting targets for how often the planes are "fully mission capable". GAO figures for the US fiscal year ending in September 2019 show the overall F-35 fleet was only fully mission capable for 31.6 percent of the time. The minimum war fighting target is 60-65 per cent.

Whether the figures improve for Australia's standard F-35A model in future years will depend on difficulties in integrating ODIN before ALIS is fully replaced. When the F-35 was conceived in the 1990s, it was promoted as a "cheap truck" for delivering bombs. A trucking firm would not tolerate having two thirds of its fleet unavailable.

Although Defence had not finished assessing the contending planes, the then prime minister John Howard chose the F-35 in 2001 when it was only a paper plane. With an inflation adjusted cost of $US400 billion for a planned US order of 2400 planes, the F-35 is the most expensive weapons program ever.

Although the unit production costs are coming down, the ongoing sustainment costs of maintenance and support are the killer. The Pentagon's Cost Assessment Office now estimates that its life cycle operating and sustainment costs will be $US1.2 trillion - a figure it described as "unaffordable".

Defence gives an average price of less than $126 million for Australia's 72 F-35s when fully delivered. But the Australian Strategy Policy Institute estimates the sustainment costs to be triple those of the F-18 fighters it replaces.

The sustainment problems are so bad that there's a serious prospect the US will keep cutting the total number of planes purchased, adding to unit costs. The US Air Force recently ordered some F-15EX fighters which have much lower maintenance costs. It can also go faster, higher, further and carry bigger weapons payloads than the F-35.

These features would have significant advantages for Australia. However, the F-35 has some more advanced attractions, in particular, its stealth capability. But the plane can be detected by over-the-horizon radars and others that operate on different frequencies to those that suit stealth. Unfortunately, stealth disappears if the F-35 carries weapons or fuel tanks on wing pylons rather than inside the plane.