On Aug 12, 1:35*am, john89 wrote:
Hello everybody,

Having recently visited an International Airport, I have got one more
question ;-)
Probably you can help me clarify something regarding the CAT II/III
marking strips. When there are unfavourable weather conditions like
fog, leading to a Category III landing approach, I guess those strips
are rendered nearly invisible!?
Is the respective CAT - marking strip possibly illuminated?
Are those markings just an indicator showing that nobody is allowed to
cross the respective strip on the taxiway while the landing manoeuvre
is being carried out?

To put it in a nutshell: What exactly do those strips indicate and how
do you know which one is currently active?


I'm not sure what strips you're referring to. AFAIK, an ILS has two
systems, both of which are radio-based - the localizer which gives you
a lateral directional reference and the glideslope which is an aid for
vertical descent.

Normally the decision-making height and runway edge visibility for CAT
II are 30 and 300 meters respectively. At CAT III airfields like LHR,
the visibility could be zilch and still land but I've heard that some
operators have their own additional safeguards written into their SOPs
like, say, 15 and 75 m even for CAT III.

Ramapriya