LVO and 90m visual from cockpit A320 question.

[Mooneyboy]

Hello all.

I’ve heard differing answers to these so wondering if I can get any clarity here.

In in the sim and performing LVTO with HIRL and 15m centreline light spacing minima RVR125m. On take-off rvr given by atc is 1st segment not working then 125/125 for mid and stop end. Our manual says ‘RVR value representative of initial part of take off run can be replaced by pilot assessment’. How many centre line lights do I need to see in from of me? Is it 6 lights ( I.e 90m visual segment from cockpit which my aircraft complied to) or 8.3 lights to give me the 125m?

Lastly before approach ban point you are doing a Cat 3a approach with minima 200/125/75. Then twr give you TDZ RVR is NA/125/75. For cat 3a you need 2 RVR readings avail. Is it legal to complete the approach? The mid and stop are reported and controlling and at or above minima. Or do I need the TDZ RVR minima for the mid i.e NA/200/75.

Also what is meant by controlling RVR?

Thanks,

Mooneyboy

[Johnny F@rt Pants]

1 - As far as I am aware, you can’t do a take off at 125m without the RVR working, so the lowest vis is 150m for take off, therefore you need to see 10 lights at 15m spacing.

2 - one RVR can be missing, therefore you can make the approach, if you can see what you need to see, land, if you can’t see what you need to,go around.

[casablanca]

My interpretation is the 90 meters is an aircraft design issue, and with correct seat position you can see at least 90 meters

[ManaAdaSystem]

One one hand CATII/III requires a RVR of not less than 300/200 m on the first segment of the runway.
On the other, on runways equipped with two or more RVR assessment units, one may be inoperative.
Tricky one, but since the table with inoperative equipment does not specify which RVR may be inoperative, you can do the approach as I see it.

For take off you can replace the RVR for the initial part of the take off run with pilot assessment.
I see that as 6 lights = 90 meters and off you go. This is simulator stuff.
If you happen to do this in real life and somebody ask you how many lights you saw? Say 10. Impossible to check.

[casablanca]

You need 200 tdz, 75,75?
if tdz is inop I would think mid could substitute but would need to be at least 200 rvr at least before the approach ban/ FAF
(at least my guess?)

[ManaAdaSystem]

You need 200 tdz, 75,75?
if tdz is inop I would think mid could substitute but would need to be at least 200 rvr at least before the approach ban/ FAF
(at least my guess?)

Yes, or if we are in simulator thinking mode, what if the runway is 3600 m long and you use max manual braking and stop on the first third of the runway?

[Mooneyboy]

Hi and thanks for the replies.

Lets say your in A320 avg pax/payload 2hr flt on 2000m RWY ( you need all 3 segments).

The example I gave was approach minima without Rollout but as correctly pointed out with rollout a cat3a minima is 200/75/75. It seems to be the consensus that the mid point RVR minima has to equal the TDZ RVR so you would need at least NA/200/75 and not NA/125/75 to make an approach ( no rollout) from above approach ban?

How does the 90m visual segment relate to RVR. Is it basically saying that if you can see 90m in front then this would equate to 125m RVR?

Thanks

Mooneyboy

[EGPFlyer]

The visual segment requirements of 90m has nothing to do with replacing the RVR for the initial part of the take off run and everything to do with being able to takeoff with an RVR of 125m. i.e. IF you have LVPs in force, you are suitably trained, the runway is certified for takeoffs at 125m (15m HIRCL 60m HIREL and multiple RVR information-must be working for all relevant sections of the runway) AND 90m visual segment is available from the cockpit at the start of the take-off run, then you can go.

The ability to replace the initial RVR is for cases where the RVR is reported to be below whatever the limit is for your takeoff, whether it’s 500m for a runway with no lights or 125m. In those cases you can line up and make an assessment. It could be that you can see, for instance, an intersection down the runway that is more than 500m away in the 1st case, or it could be that you count 8 lights if need 125m.

[EGPFlyer]

ItHi and thanks for the replies.

Lets say your in A320 avg pax/payload 2hr flt on 2000m RWY ( you need all 3 segments).

The example I gave was approach minima without Rollout but as correctly pointed out with rollout a cat3a minima is 200/75/75. It seems to be the consensus that the mid point RVR minima has to equal the TDZ RVR so you would need at least NA/200/75 and not NA/125/75 to make an approach ( no rollout) from above approach ban?

How does the 90m visual segment relate to RVR. Is it basically saying that if you can see 90m in front then this would equate to 125m RVR?

Thanks

Mooneyboy

You don’t replace the TD with midpoint anymore if the TD RVR is missing (in EASA land anyway). You used to do that but it was removed years ago. For CAT3B (no DH) you just one reading on the aerodrome, it could be on another runway a mile away....

[Dct_Mopas]

EGPFlyer,

with regards to the loss of an RVR reading, for CAT 2 and CAT 3A Ops EASA just says that if the runway has 2 or more assessment units then 1 can be INOP. So by that the TD RVR could be INOP, honestly can’t find a reference to whether the midpoint can/can’t be used instead (as long as it’s above the original TD minimum RVR).

[EGPFlyer]

EGPFlyer,

with regards to the loss of an RVR reading, for CAT 2 and CAT 3A Ops EASA just says that if the runway has 2 or more assessment units then 1 can be INOP. So by that the TD RVR could be INOP, honestly can’t find a reference to whether the midpoint can/can’t be used instead (as long as it’s above the original TD minimum RVR).



I agree, there’s nothing in the EASA regs that say what to do with your remaining RVR value. Dare I say that common sense might come into play?

[Dct_Mopas]

Ay-up, common sense and EASA in the same sentence!?

You’re quite right though, just asking in case I’ve missed another angle to this scenario. EASA Ops says 1 can be INOP, and a the same time TD RVR is always controlling. However, it can’t be controlling if INOP (common sense again).

[Mooneyboy]

Yes I’m in EASA land ( well until 29th Mar but that’s a different topic).

Ive heard of the situation of cat3b let’s say AMS 18R you could use 1 RVR on 27 as it’s same Aerodrome.

Thanks I think I now understand the 90m segment.

My ops manual says ‘The touchdown RVR is always controlling for all instrument approaches’. However and this maybe the change that came in a couple years ago it then says ‘If reported and relevant, the mid point and and stop end are also controlling’.

Does this imply if the TDZ rvr is not working then the mid point is now relevant and controlling? So if not using rollout you would need the 125m mid point as this is now controlling. Is this the right logic?

[Capt Scribble]

Its relevant if you are planning to use it. You may only need 2000m of a 3000m runway. A suitable selection of autobrake might resolve a below limit stop-end rvr.

[FlightDetent]

I fail to see the funny side of the jokes here. Good riddance, google Getting to Grips with LVO you lot. It is written for pilots, should be easier to comprehend than the regulations that’s been turned to marmalade here.

[Dct_Mopas]

I fail to see the funny side of the jokes here. Good riddance, google Getting to Grips with LVO you lot. It is written for pilots, should be easier to comprehend than the regulations that’s been turned to marmalade here.
How does a document, written in 2001, referring to JAA regulations help with EASA LVO regs?

It’s a great document, however it is out of date so caution is needed.

[FlightDetent]

It helps once you read it. It has all the information needed for the scope of this thread.

Except for a re-definition of the approach-ban point, nothing has changed with regards to LVP.

@Mooneyboy: The 90 m visual segment is not something you should assess by yourself for take-off. It is a design geometry issue, to be sorted out during your LVTO approval with local CAA.

[FlightDetent]

(f) The touchdown zone RVR shall always be controlling. If reported and relevant, the midpoint and stopend RVR shall also be controlling. The minimum RVR value for the midpoint shall be 125 m or the RVR required for the touchdown zone if less, and 75 m for the stopend. For aircraft equipped with a rollout guidance or control system, the minimum RVR value for the midpoint shall be 75 m.



‘Relevant’ in this context means that part of the runway used during the high-speed phase of the landing down to a speed of approximately 60 kt.



For a low visibility take-off (LVTO) with an aeroplane the following provisions should apply:
(a) for an LVTO with a runway visual range (RVR) below 400 m the criteria specified in Table 1.A;
(b) for an LVTO with an RVR below 150 m but not less than 125 m:

(1) high intensity runway centre line lights spaced 15 m or less apart and high intensity edge lights spaced 60 m or less apart that are in operation;
(2) a 90 m visual segment that is available from the flight crew compartment at the start of the take-off run; and
(3) the required RVR value is achieved for all of the relevant RVR reporting points;
Note well:
- the provision to "replace" the foremost RVR readout only exists as a note to table 1A, which does not come in play for LVTO 149-125 m. The idea it might apply to landing is grave lunacy.
- the requirement of 90 m visual segment stands for LVTO 149-125 m, where substitution of the measured RVR value is not allowed.

[Mooneyboy]

Thanks flight detent. I found the document getting to grips with LVO. It’s a shame it’s not more updated like the cold weather one. It’s a good document to have. Especially like the diagram explaining the 90m segment. As you say most major difference to now is the approach ban point.

Thanks for the info.

Mooneyboy

[FlightDetent]

Pleasure, be assured my aggravation was not pointed at you. When I read the Co. manual for the first time, I couldn't make any sense of it. Reviewing it after an explanation was somewhat more successful.

The first part's RVR may only be replaced by an assessment for LVTO 400-150 m. The 90 m segment is a required characteristic for 150-125 m, and no replacing or substitution is allowed. Such has been the case for long decades, irrespective of the fact that many very large airlines have been teaching their pilots the nonsense of counting lights for ages.

[Stanley Eevil]

Pleasure, be assured my aggravation was not pointed at you. When I read the Co. manual for the first time, I couldn't make any sense of it. Reviewing it after an explanation was somewhat more successful.

The first part's RVR may only be replaced by an assessment for LVTO 400-150 m. The 90 m segment is a required characteristic for 150-125 m, and no replacing or substitution is allowed. Such has been the case for long decades, irrespective of the fact that many very large airlines have been teaching their pilots the nonsense of counting lights for ages.

I have been following this thread with great interest and one of my own areas of doubt was with TDZ RVR <150m and how to apply Table 1-A.
The single `*` at the head of the table in the RVR column (The reported RVR value representative of the initial part of the take-off run can be replaced by pilot assessment) could be interpreted as applying to all the cases given, including the 125m scenario?

Can you confirm then that it is not permitted (in a scenario where the RVR is, for example, 100/125/125) to line up and establish whether you can see, say, 8 or 9 RW centreline lights ahead of you thereby confirming that in `real terms` the RVR at the TDZ is indeed 125 m?
I am happy that you can`t line up and say: well I can see a 90m visual segment (6 lights) ahead so let`s go for it!

[Airmann]

Off the top of my head I was under the impression that all RVRs had to be above 125m AND the pilots could see a visual segment of at least 6 lights. (and of course we always can!)

[Goldenrivett]

The single `*` at the head of the table in the RVR column (The reported RVR value representative of the initial part of the take-off run can be replaced by pilot assessment) could be interpreted as applying to all the cases given, including the 125m scenario?

Yes.
The argument I prefer goes as follows: The logic is the RVR measuring device is not located on the runway, it is probably 50m to the side over the grass. Thus there could be a discrepancy between what is being measured / reported, and what the pilot can actually see from the flight deck. Therefore before we start the take off, we are allowed to asses the initial part of the take off run ourselves (by counting the lights) and may replace the touch down reported value.

There was a typo several years ago which seemed to exclude RVR 125m - but that has now been corrected.
https://www.easa.europa.eu/sites/default/files/dfu/Consolidated%20unofficial%20AMC%26GM_Annex%20V%20Part-SPA.pdf

[FlightDetent]

Oh what a mess, let's see:

EU-OPS Appendix 1 (New) to OPS 1.430 - the regulation preceding the current EASA IR.

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/846x709/euops1430_bb92b7579eabe9003c52a2cbea5185d604c7c4f5.png


These are the basic rules for TKOF down to 150 m, and the table does not show any lower values. On the next page, the specific case for less than 150 m is discussed:
https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/685x382/euops1430ii_2e5c4cd192e4c75e063e13f91048956b4e64583c.png
The Exceptions to sub-paragraph (3)(a)(i) - the first picture - are clearly not derogations but rather additional restrictions imposed on top of the original, down-to-150-m, requirements. Thus where (3)(a)(i) explicitly says the first RVR if not achieved can be replaced, Paragraph 4(E) removes that possibility.

Was it a typo, or the actual intention of the law-maker instead?
The required RVR value must be achieved for all of the relevant RVR reporting points with the exception given in Note 3 above.
vs.
(when) The required RVR value has been achieved for all of the relevant RVR reporting points.

[FlightDetent]

I tried to search a bit deeper.

Find 1: The text above is identical since JAA OPS, 1999ish.
Find 2: The ICAO Doc 9365 Manual of All Weather Operations shows Table 6-2, which is inconclusive to this discussion. The order of possible priority between notes 1 and 4 cannot be determined. I still like to note that while ICAO has a single table with values all the way down to 75 m, the ECAC/JAA people chose to split it and define the (overlapping) notes more precisely, when publishing the EU regulation.
Find 3: I couldn't find the FAA version of this.
Find 4: The Australian CAAP LVO-1 https://www.casa.gov.au/sites/g/files/net351/f/_assets/main/download/caaps/ops/lvo-1.pdf clearly prohibits the self-replacement of RVR below 350 metres.

Since there WAS a re-design of the relevant paragraph, the key question is: did EASA have a change of heart? Was there a NPA process to allow 75/125/125 departures based on "seeing lights"...?

[ManaAdaSystem]

I tried to search a bit deeper.

Find 1: The text above is identical since JAA OPS, 1999ish.
Find 2: The ICAO Doc 9365 Manual of All Weather Operations shows Table 6-2, which is inconclusive to this discussion. The order of possible priority between notes 1 and 4 cannot be determined. I still like to note that while ICAO has a single table with values all the way down to 75 m, the ECAC/JAA people chose to split it and define the (overlapping) notes more precisely, when publishing the EU regulation.
Find 3: I couldn't find the FAA version of this.
Find 4: The Australian CAAP LVO-1 https://www.casa.gov.au/sites/g/files/net351/f/_assets/main/download/caaps/ops/lvo-1.pdf clearly prohibits the self-replacement of RVR below 350 metres.

Since there WAS a re-design of the relevant paragraph, the key question is: did EASA have a change of heart? Was there a NPA process to allow 75/125/125 (tel:75/125/125) departures based on "seeing lights"...?

Ahh, Aussie rules flying! Love it! Whats next? We all have to fly three legs in the pattern when we fly visual approaches?
But EU Ops rules are clear. As pointed out several times in this discussion.
6 lights and off I go.

[FlightDetent]

Clear they are, in EU-OPS which no longer is the applicable regulation. Somewhat more cloudy in EASA-IR, for those who insist on what favours them. Clear enough if you dare to think before taking conclusions.

There is one thing laid out in the ICAO doc, and believe it or mot the rules worldwide are quite harninized. The Oz rulebook is a demonstration how the same thing could be written in a different format.

Nothing has changed for decades. Why would there be the requirement to have any TDZ RVR if it can be always replaced?

[FlightDetent]

But EU Ops rules are clear. As pointed out several times in this discussion 6 lights and off I go. Try that in FRA and off you stay.

[Goldenrivett]

Nothing has changed for decades.

Correct. From a copy of my company documentation dated 1999,
"Take -off Ban .... Note: Pilot assessment of TDZ RVR when practical always overrides the reported RVR or met visibility. Pilot assessment may not be practical where runways are humped or the RVR limit is high"

Why would there be the requirement to have any TDZ RVR if it can be always replaced?
The reported RVRs are for both Landing and Take Off considerations. When landing - you can't assess the RVR yourself because you aren't physically there yet.

[Toruk Macto]

simple really .

[Capt Scribble]

If you can see 6 lights there will be 2 lights that you can not see ‘under’ the aircraft, giving 120m.

[16024]

6 lights and off I go.
I hope you are kidding.

[Mooneyboy]

Reading my company manuals with a fine tooth comb as flight detent suggested a note for 150m and below says RVR required for all relevant RVR’s. I can see how this supersedes and overrules the other note about using pilot assessment.

In over 10years only once have a ever seen a TDZ RVR below 125m and that was in MXP. It was a 100m and there certainly wasn’t any hint or requests from any departing aircraft to trot off down to the numbers and count the lights on the centre line in order to depart below the reported RVR.

Always a a little cautious regarding RVR’s as I do know someone ( although a slightly different situation to this) who got fined a couple of grand for landing below RVR minima. So not just a telling off from the company but a potential hit in the wallet!

My early sims remember a lot of counting of centreline lights but have to admit doesn’t seem to occur as much recently. Although saying that I recently listened to a well regarded podcast on Airbus 320 lvo and they were talking about counting 6lights

All the best

mooneyboy

[casablanca]

For last 20 years every checkride I have had I have heard different ideas and views from various instructors .... And this forum really drives home the fact that these regulations are so poorly written that nobody understands or can agree on something that should be very clear!

[Goldenrivett]

these regulations are so poorly written that nobody understands or can agree on something that should be very clear!
I agree that a typo with a split table over 2 pages caused lots of confusion - especially when it took 2 years to correct. However, the updated version now reflects what had been agreed for over 30 years. See page 605 of Jeppesen Air Traffic Control https://ww1.jeppesen.com/company/publications/documents/ATC_EASA_AIR_OPS.pdf

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1729x1432/rvrs_0e4a70e94cf55dc4794b72223f37f1d5383296a7.png

Does anybody have a more recent document than May 16?

[petrichor]

Yes I’m in EASA land ( well until 29th Mar but that’s a different topic).

Ive heard of the situation of cat3b let’s say AMS 18R you could use 1 RVR on 27 as it’s same Aerodrome.

Thanks I think I now understand the 90m segment.

My ops manual says ‘The touchdown RVR is always controlling for all instrument approaches’. However and this maybe the change that came in a couple years ago it then says ‘If reported and relevant, the mid point and and stop end are also controlling’.

Does this imply if the TDZ rvr is not working then the mid point is now relevant and controlling? So if not using rollout you would need the 125m mid point as this is now controlling. Is this the right logic?

Mooney - If reported, the Mid and End are also controlling - this is IN ADDITION TO the TDZ. TDZ is the primary factor, if you have others available then they too need to be legal if stated (rolling or END are not always so). Think about representing yourself in court when something went wrong during the landing - if you used an RVR other than the point you wanted the aircraft to touchdown would that be sensible or stand the scrutiny of a team of barristers?
Good questions, this is what the forums should be about

[Mooneyboy]

Recently asked one of my companies examiners and he also reiterated not using pilot assessment below 150m RVR.

Yes as you mention above imagining a court scenario and you having to defend your position can help you come to a sensible decision.

Thanks everyone for help, tips and advice.

Mooneyboy

Mooneyboy