U.S. clears $404M MC-55A upgrade package for Australia

The U.S. State Department has approved a potential $404 million Foreign Military Sale to Australia for the MC-55A Baseline 2 Upgrade program, aimed at enhancing the Royal Australian Air Force’s fleet of modified Gulfstream G550 business jets known as the MC-55A Peregrine.

According to the Defense Security Cooperation Agency (DSCA), the request includes major and minor aircraft modifications, spare parts, consumables, repair services, U.S. government and contractor engineering, technical assistance, logistics support, and other related program elements.

The DSCA said in its notification to Congress that the sale supports the foreign policy and national security objectives of the United States, describing Australia as “one of our most important allies in the Western Pacific.” The agency added that Canberra’s strategic location plays a key role in ensuring peace and stability in the region, and that helping Australia sustain a capable self-defense force serves U.S. national interests.

The upgrades are expected to strengthen Australia’s ability to maintain its MC-55A fleet, a critical asset for intelligence, surveillance and reconnaissance (ISR) missions. The aircraft also support U.S. and allied operations in the Indo-Pacific.

“Australia will have no difficulty absorbing these articles and services into its armed forces,” the DSCA noted.

The principal contractor will be L3Harris Technologies, headquartered in Greenville, Texas. The DSCA also confirmed that no additional U.S. government or contractor personnel will need to be assigned to Australia for the program’s implementation.

The MC-55A Peregrine represents a specialized conversion of the Gulfstream G550 airframe, integrating a custom sensor suite housed in a canoe-shaped ventral fairing beneath the fuselage. This configuration required major changes to the jet’s outer mold line and a new airworthiness certification process.

Speaking to FlightGlobal at the Avalon Air Show earlier this year, Jason Lambert, president of ISR programs at L3Harris, described the Peregrine as a “first of its kind aircraft.” He said that from an ISR perspective, “there’s nothing else in the world that matches MC-55.” Canberra plans to operate four of the aircraft.

The certification and integration work extended the program’s timeline, delaying first delivery from 2023 to 2025. Lambert explained that first-time development programs often face unforeseen challenges, in this case stemming from changes to the G550’s flight parameters caused by the addition of the large ventral sensor housing. L3Harris received the required supplemental type certification for the redesigned airframe from U.S. regulators in late 2024.

Lambert also disclosed that L3Harris is preparing a similar G550-based ISR aircraft for another Foreign Military Sales customer, though he declined to name the buyer or provide specifics. That platform will share the same outer mold line as Australia’s MC-55A and carry a comparable mission package.

Beyond the Peregrine, L3Harris is active in multiple business jet conversion programs, including the U.S. Air Force’s G550-based EA-37B electronic warfare aircraft and a surveillance aircraft family for the U.S. Army built on the Bombardier Global 6500.