CATIII vs. visiblilty/RVR, CATIII approach plates

[Cecco]

1.) I fly a CAT I aircraft (C525) and today on approach to EDDG, the ATIS
said "ILS 25, CATIII, NSC, visibility 700m, RVR TDZ 600m..". I considered doing the approach because the CAT I requirements were fullfilled with RVR being above 550m in the TDZ, which, in my opinion, overrides the CATIII condition announced in the ATIS.

What do you think? Furthermore, if met conditions in the ATIS would have remained, would you have radioed "Negative CATIII aircraft but eligible to ILS approach due to RVR being above CAT I limit" or something similar?

By the way, the visibility improved rapidly so CATIII progressed to CAT II, CAT I and we ended up landing in CAVOK.

2.) I´ve seen CATI/CATII approach plates on Jeppesen charts but no CATIII approach plates. Why is that? Are they specially "tailored" for the eligible operators?

Cecco

[Spitoon]

I can't give any definitive answer for EDDG but it is possible that the ATIS was simply advising that the ILS and other facilities are able to support Cat III operations - i.e. no failures and LVPs in place. If the wx is such that you are permitted to start an an approach then go for it!

As I understand it Cat III operations are always subject to approval by the CAA (or whatever) with procedures, including minima, specified in the Ops Manual.

[MarkerInbound]

1. That's interesting because all I see on the 11-2A page for EDDG are CAT II mins but the 10-9X page has CAT III mins on it. That's above my pay grade. Would have been worth asking why you couldn't do a CAT I before you divert.

2. Look at EDFH or EDDF, both have CAT II/III pages. Sometimes Jepp has separate pages for the CAT I and CAT II/III and sometimes they are on one page. I don't know why.

[grounded27]

Probably has more to do with the runway being protected for catIII rollout ops.

[Nubboy]

I'm with grounded 27 on this.

I take it to mean that all protections needed for Cat III ops are in place. If the weather is legal for your Cat I then go for it. Just remember runway exits and taxiways will be set up for LVP's, so for example, you can only come off the runway at specific (lit!) exits (normally yellows and greens).

In low vis, if Cat III ops are supported, we normally carry out a Cat III approach and landing, even if the currentr minima allow Cat II as the RVR's can go up and down like a yoyo.

[Cecco]

I found the CATIII minima at various airports.

If you look up the CATIII minima at EDDM, you will find 50ft RA, RVR200m
for CATIIIA, however, for CATIIIB, it simply says APPROVED. How come there are no minima.

Cecco

[Denti]

CAT IIIb minima depend on aircraft type and approved minima, some if not most approved types have no DH at all and need 75m RVR, however some larger types have a DH below 50ft and may require a higher RVR. The required RVR is needed for taxying or manual continuation in case of an auto-rollout failure. Even the mentioned 50ft/200m for CAT IIIa is only the minimum value, some types need different minima regardless.

The LIDO plates we use simply say "COMPANY" instead of a minimum for CAT III runways, so you have to consult your company documentation about the applicable minimum.