Philip Mew,
When approaching at DYMHL you should be near 'abeam' where 4L and 4R intersect 31L/R,
now, the procedure states explicity
" When VISUAL reference established FLY VISUAL to airport VIA LEAD-IN LIGHTS to rwy 31L or 31R. close adherence to flight track required for noise abatement...
so I would say yes for 31R need two sets for 31 L need visual contact with three LDLN, loss of adequate and proper visual contact requires a missed or a GA.
it's a screwed up visual pattern
rhov
