I suspect there are no absolutes when it comes to AVMED, as is the same when it comes to Aviation. Concepts are important. If the pressure decreases with altitude (WE KNOW THIS TO BE TRUE) then staying as low as safely possible is beneficial when it comes to having holes in your body that leak bodily fluids out board. Many car accidents result in lacerations cuts and holes etc so % wise there are large numbers of folks with holes in them when they are being transported by air. Transport by air rather than road is generally organised for the speed factor. Having to climb up/down to LSALT and let down at the other end adds t++++ (timings plus) to your mission and hence the speed factor is not as speedy as it could/should be.
As far as the DA being lower at night than day, this only makes the machine perform better (more bernoulis) not the patient. The patient is still subject to Press varies proportionally with height. As far as agencies challenging what altitude is acceptable to be flown at, they won't as the Aviatior is supposed to be the subject matter expert and hence advise what is a good compramise for flight safety vs patient transfer. Hence most non aviator folks will be happy with what is offered.
If NVG allow you as the PIC to fly below LSALT at night and hence lower than when you are unaided, then you are presenting the patient at the other end (Hospital facility) in potentially a more stable position so the dudes in the white suits can perform their duties. Enough Said.
The black hole night approach, manoeuvring and departing an unlit area is easier/safer to fly with the addition of NVG and that alone may be enough to tip the scales away from night unaided ops.
At present other EMS operations over seas have and use NVG with all the rules and regs in place, so why not OZ?
Max
