Safetypee speak with strait tongue - I council him be made Chief!
Can't comment on vintage VASIS, but PAPIs is my thang
When a runway is equipped with an ILS Glide Path, the PAPIs should be aligned so that their points of origin are the same. If you look at the drawings in CAP168, you'll notice that the angle change depends upon ILS or not.
If you fly an aircraft equal to the design aircraft then 2W 2R is set for you. If your a/c is much smaller than the design a/c, the 2W 2R will see you pass over the threshold at more than a safe height. Have a look at the AIP entry and focus on the published MEHT.
If, by any chance, you are in an a/c bigger than the design a/c the 2W 2R could result in a sudden scraping sound just before anticipated touchdown.
In other words, pilots cannot apply a broad brush criteria to the number of lights seen on approach to optimise the point of touchdown - one has to know what design a/c was used to set the PAPI angle.
Also, when were they last flight checked? How does the airport deal with new obstacles sticking up into the 4 red zone?
For answers to these and other safety questions e-mail............
er? Your guess is as Goudot as mine
Sir George Cayley