On Sat, 12 Jun 2010 13:28:34 +0100, "Recliner"
wrote:
"Bruce" wrote

That's why I mentioned approach lights and VASIs, but not ILS.

My experience was some years ago -- do you know if it's any better now?


It hasn't changed, except that the VASIs (visual approach slope
indicators) on both runways have been upgraded to PAPIs (precision
approach path indicators). Both are purely visual aids working on
similar optical principles using polarised light, and are sensitive to
cloud conditions. VASIs give an up/down indication of whether the
aircraft is on the correct glide path. PAPIs give up/down and also
left/right indications. But if you cannot see them because of thick
cloud, they are useless.

From Wikipedia:
"The main runway operates with a Category III Instrument Landing
System. The northern runway does not have an Instrument Landing System
and, when it is in use, arriving aircraft use a combination of
Distance Measuring Equipment and assistance from the approach
controller using surveillance radar, or where equipped and subject to
operator approval, an RNAV (GNSS) Approach, which is also available
for the main runway. On all runways, considerable use is made of
continuous descent approach to minimise environmental effects of
incoming aircraft, particularly at night."

RNAV (GNSS) is a navigation system, usually GPS based, that aims to
get the aircraft to a point where VASIs or PAPIs can be used for the
landing. It is very inferior to ILS which can put the plane on the
runway with a high degree of safety.

The last sentence refers to a higher altitude approach which means
pilots have to lose height rapidly to regain the traditional glide
path on final approach. The intention is to keep noise pollution to a
minimum in towns under the flight path. It is like the noise
abatement principle used for take-offs, but in reverse. It is used
routinely, and not just at night.