AAC pilots are flying soldiers, with basic infantry training at minimum, and operating in a dedicated aerial role in close proximity to ground troops, so usually fly in kit similar to the ground troops- i.e. DPM, combat boots, side arm, webbing and gat. They would be expected to join the fight on the ground if necessary (as happened in Gan). RAF SH pilots are usually insertion/evacuation, so fly in grow bags usually just with a side-arm for last resort, relying on door/tailgunners and ground support for defence. RN/RM jungly SH pilots fall somewhere between - I've seen them carrying SA80s in the cockpit.
I don't know about FJ pilots. We always suspected they just were sipping their gin and tonics.
It's all a bit role specific, so no definite answer.