Airservices Australia says that "Luscombe Army Airfield Holsworthy is a heliport. Fixed wing operators are warned the runway does not necessarily comply in all respects with applicable regulations". It's only 670m long, too. STOL or VTOL operations only!
Holsworthy Airfield was probably built around the same time as other dispersal strips such as Hoxton Park or Mt Druitt but has retained its military identity after the war. Army aviation services at Holsworthy are the principal responsibility of 161 Reconaissance Squadron. It was renamed Luscombe Airfield after Lieutenant Brian Taylor Luscombe, killed in action in Korea, June 1952. (More to read at Western Sydney Libraries)
The Australian Army says that "Headquarters 6th Aviation Regiment is located at Luscombe Army Airfield, Holsworthy and commands 171st Aviation Squadron (171 Avn Sqn), 173rd Aviation Squadron (173 Avn Sqn) and a Support Squadron (Spt Sqn)."
The Regiment currently operates Blackhawk and Kiowa Helicopters.
There's a C-130 Hercules fuselage ( C-130A Hercules A97-205) somewhere on the base, used for parachute training. This fuselage (below) doesn't look like a Hercules (more like a cross between several airliners) but is certainly visible (all images via Google Maps).
More on Sydney's airstrips and airfields.