Australia is advancing with its planned acquisition of up to five Gulfstream G550s adapted for intelligence, surveillance and reconnaissance and electronic warfare duties, with the approximately $1.3 billion deal having secured approval from the US State Department.

L3 Technologies will be prime contractor for the Foreign Military Sales deal, details of which were outlined by the US Defense Security Cooperation Agency on 26 June.

Up to five of the long-range business jets will be acquired, with airframe modifications required to accommodate mission systems and secure communications equipment. The work will be conducted at L3's Greenville site in Texas, but further details of the proposed mission system package have not been disclosed.

A self-protection suite will also be installed, with other programme elements to include ground-based data processing systems, plus spare parts and crew training services.

The DSCA says the proposed deal "supports and complements the ongoing efforts of Australia to modernise its electronic warfare capability, and increases interoperability between the US Air Force and Royal Australian Air Force".

Australia's acquisition is believed to include a lead pair of G550s which have already been ordered for conversion by L3 in an electronic and signals intelligence-gathering configuration.

Canberra's plans for an eventually five-strong surveillance fleet were detailed in a defence White Paper published in February 2016, which stated that the new capability should be fielded "in the early 2020s".