Christmas Island, Rwy 18, had one of those. It happens if you get 4 reds and are still getting lower on profile.
Can't find any reference for the YPXM installation - it may have changed.
Must have been something the local electrician / aerodrome operator thought was a good idea. Being non MoS compliant, I'd say CASA told them to get rid of it pronto. By nature of their design I don't see how you could have a transition from steady 4 red lights to flashing by descending further below the 2 deg 30' angle.
Back onto VASIs though, I flew into Leigh Creek in a lightie one night about an hour and half after last light. From memory I was aware there was a T-VASIS but when you are used to flying only into PAPIs there can be a tendency to drop down a little. The first light below woke me up to the error of my ways
What really annoys me though is PALs with no confirmation of activation.
