CAT 2 rvr

[blueskiesup]

Hi Guys, I've done a search for this but with no answers. When on a cat 2 approach, and given multiple RVR's, is it right that the mid-point reading can be 50% of the touch-down point reading?.

Plus, as an aside, anyone know where i can get a picture/or written details of the runway lights. By that, i mean when they start changing colour from touch-down to end zone?.

Cheers.

[ImbracableCrunk]

From the US's AIM:


2-1-4. Runway Edge Light Systems
a. Runway edge lights are used to outline the edges of runways during periods of darkness or restricted visibility conditions. These light systems are classified according to the intensity or brightness they are capable of producing: they are the High Intensity Runway Lights (HIRL), Medium Intensity Runway Lights (MIRL), and the Low Intensity Runway Lights (LIRL). The HIRL and MIRL systems have variable intensity controls, whereas the LIRLs normally have one intensity setting.
b. The runway edge lights are white, except on instrument runways yellow replaces white on the last 2,000 feet or half the runway length, whichever is less, to form a caution zone for landings.
c. The lights marking the ends of the runway emit red light toward the runway to indicate the end of runway to a departing aircraft and emit green outward from the runway end to indicate the threshold to landing aircraft.

[lion-g]

Hi,

For CAT 2 approach, strictly speaking we need 300m vis at the touch down zone ONLY, that's as per the policy.

We need to see at least 3 consecutive lights of centreline approach lights, touchdown zone lights or runway edge lights.

Each RW edge light are usually spaced out by 60m, touchdown zone lights 30m, and R/W centreline lights 15m.

As for the lights, the runway centreline lights is white/yellow, when reaches 3000ft to go, turns white and red and 1000ft to go all red.

Runway edge lights are white in color, taxiway edge lights are blue.

Taxiway centreline lights are green, with stop bar RED.

Lead in lines out of runway starts with alternate yellow and green till it becomes fully green when you are out of the runway.

Just some info off my head.

Cheers

[CHAPARRAL]

blueskiesup
RVR: If you are looking for EUOPS 1, see OPS 1.405 (f)

Lights: ICAO Annex 14. 5.3.13

Cheers, C.

[Sir George Cayley]

As an additional learning resource have a look at the CAA website for a publication coded CAP437 Visual Aids Handbook. There's some graphics in there that will help I'm sure.

Sir George Cayley

[zonnair]

When on a cat 2 approach, and given multiple RVR's, is it right that the mid-point reading can be 50% of the touch-down point reading?

technically TDZ is only needed, but if MID is given, it must be 125m in case of manual roll out, or 75m in case of auto roll out.