Cat III Question for Airbus drivers

[C77MD80]

This question goes out to anyone but especially the A320 drivers.

You are doing a Cat III dual, fail operational approach. Everything is working, you're all legal, trained, a/c is good, ground equipment is good and RVR is good outside the FAF. You get inside the FAF and you're controller now gives you an updated RVR and it is below your authorized minimums. I am under the assumption (because I can't find aything else on it), that once inside the FAF you can continue just like 91.175 says. Since this is a NO DH approach you could technically land zero, zero and not see a thing. My interpretation correct or is it different with Cat III No DH approaches?

 

[Clutch_Cargo]

C77,

Not a A320 driver but our op specs required a miss no later AH if the wx went below mins.

 

[JAFI]

C77, Your Airbus is most likely CATIII (b) or maybe (c). To go zero - zero landing you are looking at CATIII (d) - I do not have my AC handy. I do not think in the US we have CATIII (d) yet. I'm told some countries have that ability, but I do not think the US is there yet.

JAFI

 

[comander]

the only thing I can say is I pray to god to someday be a airbus320 driver .

 

[C77MD80]

C77, Your Airbus is most likely CATIII (b) or maybe (c). To go zero - zero landing you are looking at CATIII (d) - I do not have my AC handy. I do not think in the US we have CATIII (d) yet. I'm told some countries have that ability, but I do not think the US is there yet.

JAFI

Jafi, we are not yet Cat III certified as we are a new Airbi operator. I have no doubt that no one yet is "certified" for Cat III (d), however, I'll pose three scenarios that may clarify what I am asking

1) Landing in foggy SFO, you are outside the FAF the controller gives you the latest rvr and it is below your ops specs minimums. Obviously the answer is that you cannot accept the approach.

2) Next scenario: Latest RVR is 2400. You fly the approach the fog bank rolls in and thickens while you are about to land and it is now 200 RVR. Controllers don't have time to tell you since it just happened. You are at Alert Height, everything checks out and you are landing. Are you legal? My answer is yes, this is a NO DH approach, there is no requirement to see the runway but you met the requirements to begin the approach.

3) Scenario three is the same as above except that the controller updates you with the RVR and you are just inside the FAF. Unlike a CAT I, CAT II or fail passive CAT III, you don't have a DH and therefore don't have a requirement to see the runway; ie, "inflight visibility". How does your ops spec address it? Can you land?

This is not written in our ops spec yet, therefore I am curious to how other Airbus operators handle the above, thanks...

 

[JAFI]

3) Scenario three ... and therefore don't have a requirement to see the runway; ie, "inflight visibility". How does your ops spec address it? Can you land?

This is not written in our ops spec yet, therefore I am curious to how other Airbus operators handle the above, thanks...

First I do not know the equipment you have on your aircraft. And as a "new" airbus operator you may not get the lowest min's right away. I am not sure why you think you do not have to see the runway to land.

Part of this has to do with the equipment (part of the CATIII a, b, or c certification) on board and your maint. program to keep the equipment certified as CATIII equipment. The CATIII certification can get "involved".

That being said, I understand on the larger aircraft like the 747-400, the cockpit could still be in the clouds while the wheels are on the runway. I am not sure what your aircraft will be allowed to do. The operations that I have seen all have to see the runway prior to the missed approach point or they must do the missed.

JAFI

edit, let me throw some info out there just to show you I cannot answer your question with out a large amount of time with your program.

For CAT certification there are aircraft with auto land and with out, with auto brakes and with out, the auto flight system tolerances are varied from aircraft type and installed equipment, then do not even bring up the MEL issues at this point for degrading the system. You have fail, fail passive, fail active, some other fail systems, then some aircraft that were first certified fail passive "can" be considered fail active but not all the time depending on a list of conditions. Then you have to bring in the maintenance program. How long have you had it with what success in QC. And on and on...

And I have just scratched the process. Give me a couple months, two large bottles of aspirin and antacids and I may come close to your answer.

In short the certification of your CATIII a, b, or c depends on your program which will determine how low you can go before you go missed.

The poster below this post did answer the "inside/outside the FAF" question. I tried to answer the how close to zero-zero question.

 

[mynameisjim]

For the 320, NWAs ops specs allow for the RVR to drop below mins past the FAF. prior to the FAF all three RVRs are required and controlling. after the FAF they are advisory only.

 

[atldc9]

We have Cat III (b) on the 717, 600 RVR and a 50' DH. For us, if the RVR drops below 600 at any point after the FAF, you can continue to DH, but must go around if the reported vis does not come up to at least 600 - 600 - 600. We are a fail passive system though. The requirement for the go around is in our op's spec's.

 

[Singlecoil]

We have Cat III (b) on the 717, 600 RVR and a 50' DH. For us, if the RVR drops below 600 at any point after the FAF, you can continue to DH, but must go around if the reported vis does not come up to at least 600 - 600 - 600. We are a fail passive system though. The requirement for the go around is in our op's spec's.

I think you meant to say, 600-600-0. The roll-out is just required to be operating, it can read 0 and you can still do the Cat III.

 

[Snoopy58]

atldc9,

Interesting... am I understading you right here?

If you're flying a Cat I approach, and RVR goes below your Cat I mins (say, below 2400) inside the FAF, you can continue & if you see what you need to at DH, you can land, yes?

But if you're flying a Cat III approach & RVR goes below your Cat III mins (less than your 6-6-6) inside the FAF, you continue to your 50' DH, but then even if you see the lights, if the REPORT is still below mins, you're going around FROM FIFTY FEET??? Seems unnecessarily sporty, setting yourself up for a go-around where you know you have a fair chance of touching down part-way through it!

Also seems a little backwards, but my job doesn't have IIIb stuff or any autoland, so I'm not familiar with how the rules go with that sort of thing. For us, with Cat IIIa on a HUD, the looksee rules don't change: inside the FAF, if RVR goes below mins, you still continue to DH, and if you see what you need to, you land. (If an RVR goes inop, however, you go around immediately.) No difference between Cat I vs Cat IIIa.

Thanks for your comments.