Sydneysiders were treated to a "rare" sight in the sky as six military planes roared over the harbour and the city's outskirts to mark the 75th anniversary of the Royal Australian Air Force's No.37 squadron.
The C-130J Hercules transport aircraft flew over the harbour about 1pm on Friday, before they headed west over RAAF bases in Glenbrook and Richmond.
Commanding Officer of No. 37 Squadron Matt Cooper said the fly-over was partly to say 'thank you' to Sydney for its continued support of personnel and their families over the years.
"It's a rare occasion that we're able to have six aircraft together to fly this formation," Wing Commander Cooper said in a statement.
The squadron played a "critical" role in how defence personnel were delivered to the frontline and returned home safely as well as supporting humanitarian assistance and disaster relief operations, he added.
No. 37 squadron was formed in 1943, during World War II, and flew around Australia and into South East Asia.
It was stood down in 1948 but re-established 18 years later, and has almost exclusively flown variants of the C-130 Hercules since then.
The squadron has a fleet of 12 planes, including two on deployment in the Middle East. Crews have been involved in disaster relief missions including Cyclone Tracy, the Bali Bombings and the Boxing Day Tsunami.