Visual reference cat 3b
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Visual reference cat 3b
Hi guys,
I have some doubts about visual reference for cat3b no DH.
Do you confirm that in easa euops 1.430 new is not allowed to continue the approach during a cat 3b with no DH if you don't have at least one light?
May I continue the approach (cat 3b) after OM, or equivalent position, if rvr falls below minima?
I have some doubts about visual reference for cat3b no DH.
Do you confirm that in easa euops 1.430 new is not allowed to continue the approach during a cat 3b with no DH if you don't have at least one light?
May I continue the approach (cat 3b) after OM, or equivalent position, if rvr falls below minima?
Don't confuse no DH with no RVR, you still require 75m for a CATIII b no DH. So if you are outside the OM or above 1000' (if no OM exists) and you get a RVR report below 75m (very unlikely) then you can't continue the approach. If you are within the OM or below 1000' and the report is below 75m you can continue and have a look.
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Hi Ollie Onion,
thanks for for replay.
There are some differences between old and new appendix of euops 1.430.
Just interpretations! I have my idea but I'm not sure that is the correct one
thanks for for replay.
There are some differences between old and new appendix of euops 1.430.
Just interpretations! I have my idea but I'm not sure that is the correct one
Cat 3B no DH means no visual ref required. Cat 3B with a DH requires 1 centreline light. You must have the min RVR reported before 1000', any reported RVR after that can be ignored.
This hoary old issue keeps coming around................
Consider this: RVR issued of less than 75m - very unlikely, HOWEVER why has a value of 75m been derived? It is to allow the aircraft to vacate the runway VISUALLY
plus, more importantly, to give the fire services sufficient visibility to find their way to any airfield incident. Now, if the fire srevices cannot guarantee a response due to low vis. then it is highly questionable whether one is now operating with legal fire cover!
I have tried in the past to extablish this minimum visibility for fire services but no one seems to have a definitive answer. This the reason why CATIIIC pioneered by BEA on the Trident never caught on. (CATIIIC = true 0/0 ops.)
Consider this: RVR issued of less than 75m - very unlikely, HOWEVER why has a value of 75m been derived? It is to allow the aircraft to vacate the runway VISUALLY
plus, more importantly, to give the fire services sufficient visibility to find their way to any airfield incident. Now, if the fire srevices cannot guarantee a response due to low vis. then it is highly questionable whether one is now operating with legal fire cover!
I have tried in the past to extablish this minimum visibility for fire services but no one seems to have a definitive answer. This the reason why CATIIIC pioneered by BEA on the Trident never caught on. (CATIIIC = true 0/0 ops.)
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If you are within the OM or below 1000' and the report is below 75m you can continue and have a look.
Once you're passed the OM/1000' point, the decision is made.
There is no requirement to be visual with the runway at any stage of a CATIIIB approach and landing with no DH. If you are using a "mini DH" which is normally 25ft (Leeds Bradford, anywhere in France) you need to be able to see one centre line light.
Spot on, assuming no relevant failures you are going to land off a CAT3b with no DH. Once you have passed that point with a legal RVR you have satisfied the regulations and you can continue the approach to a landing regardless of the what the RVR drops to.
Quite logical if you think about it. RVR is not uniform across even quite small areas and can fluctuate rapidly. If you are given 75m at all 3 points it is quite possible that the RVR at the runway turn-off could be 50m or 90m. The threshold RVR can often be very different from the reported viz. which is why lots of CAT1 approaches to 550m/200ft end in go-arounds, you can't see the runway at DH despite the fact that the reported viz is at or above minimums.
The regulations recognise their own limitations and that of the measuring system which is why they allow you to continue to DH if you have one, or to land if you don't, once you are past the OM.
Once you're passed the OM/1000' point, the decision is made.
Quite logical if you think about it. RVR is not uniform across even quite small areas and can fluctuate rapidly. If you are given 75m at all 3 points it is quite possible that the RVR at the runway turn-off could be 50m or 90m. The threshold RVR can often be very different from the reported viz. which is why lots of CAT1 approaches to 550m/200ft end in go-arounds, you can't see the runway at DH despite the fact that the reported viz is at or above minimums.
The regulations recognise their own limitations and that of the measuring system which is why they allow you to continue to DH if you have one, or to land if you don't, once you are past the OM.
