SASless; re your post #223.
Where were these gunships based that they could only operate from 1000-1500? Gunships did not operate in the dark? What of this thing about B Model gunships being no good?
Some of the US Army gunship elements that supported 1ATF pre-April 1969 were based in the IV Corps area embracing the Mekong Delta. The problem was an inefficient tasking system which we were told aimed to give a balance of experience to US Army aircrew. On one occasion while I was doing a short exchange with 135th AHC based at Blackhorse near Nui Dat (Phuoc Tuy Province), we were tasked for operations around Tay Ninh up near the Cambodian border.
I did not say US Army gunships did not operate in the dark; on 2 night tasks where I led missions, they provided excellent support. But on one occasion where a LFT left us late in the day to transit home somewhere down the delta (callsigns escape me now), we were told both aircraft were found about 2 weeks later but no awareness of what happened to the crews.
The XM-16 weapon system as fitted to old Bravo models, and trialled by 9SQN, had 4 x traversible M60s beset with a lot of reliability problems. It was being replaced by the XM-23 system fitted to Charlie models incorporating 2 x traversible miniguns and that model aircraft also had an enhanced rotor system. US Army units naturally had precedence for hardware and spares support in their own supply system, so we had to barter XM-23 components for experimental adaptation of that system to Hotel models. After we had proven the Bushranger concept, the Australian government then authorised the princely sum of $94,000 for acquisition of 4 sets of hardware. The US Army gave us some crap gear which we ultimately replaced with newer stuff through conniving their supply system and also having high level representations made in Saigon. As we began receiving Hotel models early in 1968, the Bravo models were progressively returned to Australia and were utilised mainly for helicopter aircrew training and for search and rescue detachments at multiple Air Force bases.
You infer in your later post #223 that the successful development of the Hotel model Bushranger gunship was inappropriate and the Air Force should have perhaps re-organised along US Army lines. I am sure you would have trouble convincing many contributors here that would have been beneficial considering the achievements of 9SQN thoughout the whole campaign. What has always irritated the senior echelons of the Australian Army was that they wanted supporting elements under command (sort of like helicopters tied up outside tents like horses) whereas operational control was adequate and conformed with the joint doctrine existing at the time.
On a separate tack, the 9SQN effort in the Battle of Long Tan was laudable, but that was an early days microcosym of involvement in other significant actions. Hovering ammunition resupplies and coincident casevacs during enemy engagements were also not uncommon throughout the remainder of the campaign. Recorded history does not get those aspects adequately in perspective.