A report obtained by the ABC has recommended the use of full-time dehumidification units to offset the corrosion risk to the F-35 Joint Strike Fighters stationed at RAAF Williamtown.
The KPMG report focused on the risk of intergranular corrosion posed by salt and ‘other climatic conditions’ to an aluminium alloy (AA 7085) used to build the aircraft.
"AA 7085 is reported to have increased susceptibility to intergranular corrosion," the report said. “This can degrade the material properties causing stress cracking and cause tensile stress which can impact adjacent components."
Cost estimates of the infrastructure required to offset the problem were redacted in the version of the report seen by the national broadcaster. The report did not find the jets stationed at RAAF Tindal or at Luke Air Force Base, Arizona to be at risk.
Whilst the climatic conditions other than salt spray contributing to the corrosion risk are not clear, the Hunter region has had a high number of air quality alerts issued in recent years, including 72 in September 2017.
A sharp rise in coal production may be to blame as it accounts for 90 per cent of regional industrial-sourced coarse particle air pollution. Additional pollution is generated by coal-fired power stations at Bayswater and Liddell.
A study found that rates of course particulate matter of 10 microns (PM 10) in the Hunter were ‘significantly higher’ than metropolitan Sydney even after controlling for weather conditions.