Australia has taken delivery of its fourth and final Boeing C-17 strategic transport, with the contract completed on time and within budget, according to the nation's air force.

The aircraft was accepted at Boeing's Long Beach, California facility in January, and has since been fitted with self-protection equipment in the USA.

The Royal Australian Air Force's 36 Sqn declared initial operational capability with the C-17 last September, and expects full operational capability to be achieved in late 2011, after training systems and permanent facilities have been completed at RAAF Amberley, Queensland.

The C-17 has had a "positive impact" supporting Australian Defence Force operations in Iraq, Papua New Guinea and Timor-Leste since the RAAF's first example entered service in December 2006, says chief of air force Air Marshal Geoff Shepherd.

Australia's Department of Defence says 36 Sqn is currently working towards more complex roles for the type, such as the airdrop of personnel and cargo, and high dependency aero-medical evacuation.