CAT IIIB no DH
 

Hi all

Can someone confirm for me that during a CAT 3B approach NO DH, after passing the OM (or equivalent.....) if the RVR drops below 75m, a Go-Around must immediatly be initiated?
In the Eu-Ops approach BAN I couldn't find it. :ugh:

OPS 1.405
Commencement and continuation of approach
(a)
(b).....
(c) If, after passing the outer marker or equivalent position in accordance with (a) above, the reported RVR/visibility falls
below the applicable minimum, the approach may be continued to DA/H or MDA/H.
(d)...
(e)...
(f) ...

Thanks

you can continue and land if the RVR falls below the minimum and you have already passed the outer marker. Since there is No DH there is no Go around "decision" to be made (ie there is no requirement for visual reference for landing). RVR for Taxi is another story.

If you consider the above scenario for a cat 2 or cat3a or cat 3b with DA(H) there is no requirement for an immediate Go around if the RVR dropped below the minimum after the OM. you are allowed to simply fly to the minima, see if you have the required visual reference and if you do you can land (even though the RVR stays lower than the requirement all the way from OM to touchdown). same applies to a CAT3B with no DH. Fly to the DH (zero).

You may continue to your MDA/DH if you have one. In the case of a no DH CAT IIIb approach you have no DH so you cannot continue your approach to it.

Background is that with a DH you can continue to the DH and very well meet the required visual segment and therefore decide to land. With no decision height no decision can be taken, no visual segment is possible and therefore the approach has to be discontinued once the RVR falls below 75m.

In my outfit we operate a mix of CAt IIIa and CAT IIIb capable aircraft of the same type and the regulator therefore demanded that we change the sentence in our OM A as follows:

Denti,

It's not definative and varies with organisation and jurisdiction.

in our ops manual it says this

the background being just as I stated in the previous post. There is no decision to be made. the there no requirement for visual reference, and RVR is not controlling after 1'000 AAL.

In the absence of any specific prohibition on continuing the approach and landing, I would continue and land. think about it. why are we allowed to go to 100 for cat2 and 50 for cat3a but we must immediately carry out an missed approach for a cat 3b with no DH. it makes no sense

As I understand it 75 metres was considered the minimum required for taxiing.

Topper80, as per EU OPS one may continue and land regardless of RVR beyond the approach ban. :ok:

Cat IIIB , already past the OM, we are allowed to continue and land,even if the RVR goes bellow 75m. BUT ,you are not allowed to taxi after landing , so you will block the rwy after landing.

Same with us, last RVRs passed before 1000' are controlling, RVRs passed below 1000' are not...and no RVR limit for taxiing off the runway:E

A CATIII approach without a DA/H instead has an Alert Height. There are still decisions to be made, that are different prior to AH and after it. The decisions just are not the classic decision required at DA/H.

Topper80,

CatIIIB no DH ,the gate will be Alert Height before, if something happen you Go-Around , after you 'll go around only in case of RED Autoland light.
Concept of minima change in aircraft cabability to land (frozen below A.Height). So A point is Cpt discretion (regarding aicraft sistems) , B is controlling for roll-out (75) C is controlling if you 'll enter that part of rwy.
75 is to allow commander to monitor the automatic roll-out phase.

Topper80: In the `60s BEA trialed Cat3C (true zero/zero) with their Tridents. What became rapidly apparent was that in conditions of very poor visibility there were problems with whether the airport fire services could in fact operate well enough to find any aircraft which might need them. This raises the issue of whether one is then operating without fire coverage. I think this plus the taxying issue may be why true Cat3C never seems to be found now.

All the other postings about whether the landing would be legal are covered by others. It would be most interesting to hear what the relevant fire services say on the matter - what with " health and safety" being so important now!
In fact the legality of the operation may hinge on the level of fire coverage in place.

After two days of silence I am surprised that none of the legal eagles on these boards have been able to come up with an answer regarding low vis fire cover.

BOAC - where are you?

What has Alert Height got to do with RVR?? Alert height is concerned with Autoland capability and is there with or without a DH. Yes if a Degradation happens before the alert height you will be alerted and will then need to consider safest course of action - either continue to the new pre-briefed Minima or in most cases go around and setup for another approach. However this doesn't relate to the original question.

Ciao Topper,

in jaa ops you had to go around if RVR dropped below minima...
euops changes things....

Hi Michelda,

so, in a 3B after the OM, if yuo get "last RVR 50" would you continue to landing?

Hi Topper,

without any problem. This is what is written in euops......unless something different is reported on your Om/a.

Michelda

What would you do if inside approach ban (CAT 3B NO DH manual rollout)
RVR rep below 125?

Hi MD83,

Are you sure that it is possible to fly CAT3B No DH with manual rollout?
I don't know with HUD, but without it is impossible.

Hi michelda if the rollout RVR is 125 i should be able to fly a
cat3b manual rollout 75 125 125
eg. contaminated rwy