MILITARY CHOPPER OVER SWAN RIVER, PERTH, WA

Lads, about 90 minutes ago I was down at the river sitting on a bench after cycling and a camo military chopper appeared from the direction of the Perth Intl. Airport, banked near the Raffles, circled over Canning Hwy exit, circled near some construction twice and then headed in the direction of Fremantle or (I assume) Campbell Barracks and now I can see RAC rescue heading in the same direction, anyone know what's up? I took some shitty phone footage but it's nothing special. I'll cross-link to the main general too.