The scourge of PAPI replacing T-VASIS
First of all I want to state the fact that I am not colour blind!
I was approaching Melbourne Runway 34 for the first time since the runway works had been completed and have to say that I found the new PAPI system next to useless!
We were flying in from Tasmania via HOBAY so we had the PAPI system in view for an extended period of time.
Where the old T-VASIS gave you an unambiguous indication of where you were on the visual approach path, I found the PAPI approach path information to be profoundly nebulous and quite unacceptable.
Everyone who flies in to Melbourne knows that the runway slope is quite significant on that runway. From 330 ft AMSL at the 34 threshold to 434 ft at the aerodrome reference point (which is located just 1500 metres along and 450 metres to the east of the centreline). This slope gives the illusion that you are high when on the 3 degree slope and if it wasn't for the visual slope guidance, many aircraft would approach the runway much lower than desired.
Anyway the old T-VASIS had essentially 7 separate rows of lights to indicate glide path angle (three for high and three for low). The lights were either in-view or not -in-view (which is literally as easy to interpret as black or white).
Now we have a PAPI system with just four lights in a single row which change between white and red in a progressive fashion from four red no white lights to one, two, three, and four white no red lights. The pilot is now required to perceive this difference in colour from the single light source, and also perceive a change in colour as the aircraft moves above or below the ideal glide path to the lights.
This sounds fine in theory however the reality is not quite there. Two points need to be made.
1. The white light is not white at all but rather a light shade of pink.
2. When a light is transitioning from white to red or vice versa, it does it gradually, so that the change can go unnoticed!
The other day I transitioned from 1-red 3-white, to almost 4-red 0-white without it ever really grabbing my attention. By that I mean the PAPI didn't shout out to me the changes that were happening. T-VASIS would have! It was more the fact that I realised that the picture looked normal which wasn't normal for this runway! It should have looked as though I was high. That was when I realised that the PAPI was no longer indicating 3 pink but rather 3 red lights.
Never mind the fact that the T-VASIS allows you to nominate multiple aiming points where the PAPI only allows you to nominate one. And that one point is always set up for a B747 often with an eye crossing height over the threshold of around 70 feet.
Anyway the purpose of this post is to gauge the feelings of other pilots about the apparent inevitable demise of the far-superior AUSTRALIAN T-VASIS system and wonder if there is anyway to halt and even reverse the installation of PAPI at major airports around the country.
Does anyone have information about the cost associated with installing and maintaining the two systems?
I wonder if pilots can exert any pressure on the people responsible.