Manila runway 24 ILS was a place where the glide path was dodgy on occasions. One day we were radar vectored high on 7 mile final and expected to see full scale fly down on ILS. Instead the needle showed just a fraction of a needle width high with rate of descent and DME versus height indicating a false glide slope indication in the region of five degrees.
A few months earlier a B707 had crashed just short of the same runway due to a high rate of descent all the way from 20 miles out. The pilot swore that he was on glide slope. He probably was - but on a false glide slope which was later confirmed by a calibration aircraft to be five degrees.