RAAF signed off on $16bn F-35 fighter program despite ?deficiencies? with aircraft, audit reveals

Australia's air force chief ticked off on a $16bn Joint Strike Fighter program clearing a major milestone despite acknowledging "deficiencies" with the aircraft and support systems.

The defence department has also revealed that a much-trumpeted upgrade to the Jindalee Operational Radar Network is running "several years" behind schedule, a year after the Morrison government announced plans to expand surveillance of Australia's eastern approaches.

The disclosures follow moves by the defence minister, Peter Dutton, to dump the trouble-plagued MH90 Taipan helicopters early and replace them with Black Hawks from the US in coming years.

A detailed new report on Australian's defence acquisitions outlines problems with other major projects, including the Joint Strike Fighter program.

Australia is acquiring 72 F-35A JSF aircraft to replace the F/A-18A/B Hornet. Forty have already arrived with the final ones expected to be delivered by late 2023.

The then defence minister, Linda Reynolds, announced last December that the F-35A fleet had "accomplished all the required testing and materiel delivery" to declare an "important milestone" known as Initial Operational Capability (IOC).

When she announced the "remarkable" achievement on 28 December, Reynolds described them as "the most advanced, multi-role stealth fighter in the world".