Defence said the Landing Helicopter Dock (LHD) vessels are due to complete their maintenance period this week after rectification of emergent issues with their propulsion systems.
HMAS Adelaide is due to leave the dry dock at Navy’s Fleet Base East today and, once undocked, will undergo sea trials and return to its operational capability program over the next few months.
HMAS Canberra completed initial propulsion sea trials in May, with trials indicating the vessel will be able to return to sea on 29 June to participate in Exercise Talisman Sabre 2017.
As previously reported, Adelaide moved into the dry dock at Navy’s Fleet Base East in May and underwent a range of tests, including a detailed inspection of the propulsion pods, defect rectification and maintenance.
The LHDs, which cost about $1 billion each, were designed and built by Spanish company Navantia with help from German company Siemens and British firm BAE Systems.
As previously reported on Defence Connect, Vice Admiral Tim Barrett confirmed at Senate Estimates in May that there had been a migration of oils across seals in the azimuth propulsion pod systems and that investigations were continuing to confirm whether this was a design problem or related to damage from excessive use.
At the estimates, the Chief of Navy delved into the issues with the aircraft used on the LHDs, along with the aircraft's capabilities and limits.
"There have been a number of incidents with aircraft MRH in our ships at sea, the aircraft itself does not have a rotor brake which means the blades slow by themselves when the engine's engaged and during that period there is always a chance that wind will affect the disc as the rotor slows," said VADM Barrett.
"We have had incidents ... where those blades have exceeded what we would normally consider to be relevant engineering limits."
Defence has now confirmed the docking and inspection of Adelaide identified wear in some bearings in the port pod, which is assessed to be the likely cause of the oil contamination.
The propulsion system of Canberra has been recertified for seagoing operations with minor restrictions in place until Canberra’s planned docking in the third quarter of 2017.
Both ships are expected to return to service before the end of 2017 following these periods of defect rectification, maintenance and trials.