LVTO: RVR reduction to 125m
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I'm wondering what your companies requirements are and what your opinion is about the above .
The reported RVR/Visibility value representative of the initial part of the takeoff run can be replaced by pilot assessment except during operations with reported RVR below 150 meters (Cat C)/200 meters (Cat D).
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Let's consider a practical example, it's always best way to find out. Let's say LVO is in force in you're in EHAM. Takeoff minima are predicated on EU OPS compliant AOC holder. The question is: what's the applicable T/O minimum for a cat C aircraft provided the operator has been approved below 150 m? 
P.S. Do I need a visual segment of 90 M for 75 M RVR approved minimum?
P.S. Do I need a visual segment of 90 M for 75 M RVR approved minimum?
Last edited by 9.G; 12th Apr 2011 at 16:36.
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Torque2 - I think you have missed the point of this thread - most of us are NOT discussing 'personal interpretations' but the way it is interpreted (or not) by companies and regulatory authorities. Obviously if the OM says "an IRVR (or a 'reported RVR') 'of >125m is required" that is an end to it. No-one is suggesting ignoring the OM and making up your mind on personal preferences. If the OM just says '"RVR>125m" and does not distinguish between pilot interpretation or other there can be confusion, as evidenced.
From FD post#9:
"many TREs differ in opinion, and some CAAs as well (evidenced by approved OM-As)"
The OP asked
"I'm wondering what your companies requirements are and what your opinion is about the above ."
We now know yours and Noaks. It is others we are seeking.
From FD post#9:
"many TREs differ in opinion, and some CAAs as well (evidenced by approved OM-As)"
The OP asked
"I'm wondering what your companies requirements are and what your opinion is about the above ."
We now know yours and Noaks. It is others we are seeking.
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BOAC no I haven't missed the point of the thread. I have stated my company's position and said no further personal interpretations required. That refers to my position. I think that exactly answers the OP's question?
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Originally Posted by 9.g
Do I need a visual segment of 90 M for 75 M RVR approved minimum?
-----
(a) Take-off minima
1. General
(iii) When the reported meteorological visibility is below that required for take-off and RVR is not reported, a take-off may only be commenced if the commander can determine that the RVR/visibility along the take-off runway is equal to or better than the required minimum.
(iv) When no reported meteorological visibility or RVR is available, a take-off may only be commenced if the commander can determine that the RVR/visibility along the take-off runway is equal to or better than the
required minimum.
(iv) When no reported meteorological visibility or RVR is available, a take-off may only be commenced if the commander can determine that the RVR/visibility along the take-off runway is equal to or better than the
required minimum.
As far as pilot assesment goes, I believe we can rule out these two paragraphs right away because no matter the conditions around threshold, under LVC one simply cannot determine that the RVR/visibility along the take-off runway is equal to or better than the required minimum.
Hence we're left with (a)(3)(i):
Note 3: The reported RVR/visibility value representative of the initial part of the take-off run can be replaced by pilot assessment.
Note 4: The required RVR value must be achieved for all of the relevant RVR reporting points with the exception given in Note 3 above.
and for 125m exception from (a)(3)(i):
(E) the required RVR value has been achieved for all of the relevant RVR reporting points
It really is the same as Torque2 says: The pilot asssement waiver is not allowed under 125m ops.
To simplify company standards, we do not allow replacement of reported RVR at all.
Yours,
FD (the un-real)
Only half a speed-brake
zonnair: I just read your question again, here's my view based on opinions and quoted regulations above.
a) There is no such thing as RVR pilot replacement for 125 m ops.
b) You need to have 90 m segment at TOR start, this is achieved by:
i) airframe geometry (A32S will give you 112,5 under 125m RVR) and
ii) counting 6 lights spaced 15 m apart.
In a hypotetical situation, where measured RVR is not reported and you would want to determine it from the cockpit, to get 125m 8 lights are needed on 320. Still the excercise is futile because this does not satisfy the general "along the runway" requirement.
Yours,
FD (the un-real)
a) There is no such thing as RVR pilot replacement for 125 m ops.
b) You need to have 90 m segment at TOR start, this is achieved by:
i) airframe geometry (A32S will give you 112,5 under 125m RVR) and
ii) counting 6 lights spaced 15 m apart.
In a hypotetical situation, where measured RVR is not reported and you would want to determine it from the cockpit, to get 125m 8 lights are needed on 320. Still the excercise is futile because this does not satisfy the general "along the runway" requirement.
Yours,
FD (the un-real)
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The whole thing is complicated by the wording of the 'law' - there is nothing in anything quoted above that specifically FORBIDS pilot assessment of TD RVR. All that 'RVR' means is Runway Visual Range' - normally 'reported' or 'IRVR' but not necessarily. Most operators distinguish between 'RVR' and 'Reported RVR' - I cannot see that EUOPS do,
If individual companies choose to implement such a bar for <150m, that is fine and fits with my feelings, but what Zonnair is asking for is the RULE. There appears to be no clear rule - hence no doubt the multiple opinions from regulatory authorities and TREs. The addition of the words "For operations below an RVR of 150m, a reported RVR is required at all relevant points" perhaps? Also the question revolves around TD RVR ONLY, not mid and stop, which as I stated above OBVIOUSLY have to be provided and there needs to be no discussion of that. Pilots are, of course, still at liberty to decide that the ACTUAL TD RVR is insufficient despite an IRVR/Reported RVR 'OK' reading.
FD - from where did you derive '8 lights'?
If individual companies choose to implement such a bar for <150m, that is fine and fits with my feelings, but what Zonnair is asking for is the RULE. There appears to be no clear rule - hence no doubt the multiple opinions from regulatory authorities and TREs. The addition of the words "For operations below an RVR of 150m, a reported RVR is required at all relevant points" perhaps? Also the question revolves around TD RVR ONLY, not mid and stop, which as I stated above OBVIOUSLY have to be provided and there needs to be no discussion of that. Pilots are, of course, still at liberty to decide that the ACTUAL TD RVR is insufficient despite an IRVR/Reported RVR 'OK' reading.
FD - from where did you derive '8 lights'?
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Nobody is objecting specific manual statements of a particular operator but since it was brought up, well my part A EU OPS compliant, says RVR 125 can be replaced by pilot's assessment. There we go again. However that's not the point, we're trying to assess the not so clear statements in the body of law by looking at it from different points of view and practical relevance. In my opinion the best way to do so is to look at a practical example. So here I am, sitting in the cockpit of a modern jetliner in EHAM with LVO being in force and RVR reported 125/125/125 facing the problem of ambiguous interpretation about pilot's assessment of the initial RVR. What does a mortal commander do in this case apart from nominating T/O alternate? Well, the very first thing would be to find out what's the airdrome minimum coz I know what's the crew's and the A/C's minimum. Where do I look, no brainer there, 10-9a takeoff minimas. What does it say? Again, no brainer there, 125M. Note it's EU OPS minima as the Title says "Standard". Hmm, there comes T2 as a friendly copilot drawing my attention during the briefing that NO assessment is allowed for the initial part, so far so good. I do have my doubts though thus I wanna dig a bit deeper and as no clear statement can be obtained from part A I refer to the other approved and official source of information seeking clarification namely Jeppesen. Where do I look, no rainer here either, chart description for Legend for EU OPS-1 AOM :
TAKE-OFF MINIMUMS
The application of these minimums may be limited by the obstacle environment in the take-off and departure area. The RVR/VIS minimums are determined to ensure the visual guidance of the take-off run phase. The subsequent clearance of obstacles is the responsibility of the operator. Low visibility take-off with RVR/VIS below 400m requires the verification that Low Visibility Procedures (LVP) have been established and are in force. RVR/VIS for the initial part of take-off run can be replaced by pilot assessment. The multiple RVR requirement means, that the required RVR value must be achieved for all of the relevant RVR reporting points, except for the initial part, which can be determined by pilot assessment. Approved operators may reduce their take-off minimums to 125m (aircraft categories A, B, C), 150m (category D) or to 75m (all categories) with an approved lateral guidance system.
The sample depict exactly the same takeoff minima as 10-9a for EHAM.
It doesn't seem to satisfy the doubtful minds, well let's go a step farther then. Let's read the EU OPS itself, no problem it's still in the very same Jeppesen under ATC management EU OPS AOM, takeoff RVR/VIS table 2 and it's all in one table down to 75 m. Finally if was taking off with RVR 75 M how many RVR reading do I need? Theoretically none but to make me visible to the emergency services and being able to taxi off te runway 2. coz my ops specs say
Well the final conclusion is do whatever the OM A says in the absence of a clear cut statement exercise sound judgment in set your priorities straight. Good luck.
P.S. let's imagine the same situation in Denver Int. with LVO and RVR 300 ft. equal to approximately 91 m. There's no doubt only 2 are required and NO 90 meters visual segment will be visible from the flight deck, I'm afraid. Happily will I take off without TDZ RVR available and land 10 hours later in EU OPS land.
I do have my doubts though thus I wanna dig a bit deeper and as no clear statement can be obtained from part A I refer to the other approved and official source of information seeking clarification namely Jeppesen. Where do I look, no rainer here either, chart description for Legend for EU OPS-1 AOM :TAKE-OFF MINIMUMS
The application of these minimums may be limited by the obstacle environment in the take-off and departure area. The RVR/VIS minimums are determined to ensure the visual guidance of the take-off run phase. The subsequent clearance of obstacles is the responsibility of the operator. Low visibility take-off with RVR/VIS below 400m requires the verification that Low Visibility Procedures (LVP) have been established and are in force. RVR/VIS for the initial part of take-off run can be replaced by pilot assessment. The multiple RVR requirement means, that the required RVR value must be achieved for all of the relevant RVR reporting points, except for the initial part, which can be determined by pilot assessment. Approved operators may reduce their take-off minimums to 125m (aircraft categories A, B, C), 150m (category D) or to 75m (all categories) with an approved lateral guidance system.
The sample depict exactly the same takeoff minima as 10-9a for EHAM.
It doesn't seem to satisfy the doubtful minds, well let's go a step farther then. Let's read the EU OPS itself, no problem it's still in the very same Jeppesen under ATC management EU OPS AOM, takeoff RVR/VIS table 2 and it's all in one table down to 75 m. Finally if was taking off with RVR 75 M how many RVR reading do I need? Theoretically none but to make me visible to the emergency services and being able to taxi off te runway 2. coz my ops specs say
If three RVR sensor are installed, TDZ, MID and Rollout are controlling. If any one RVR is inoperative, the other two are required and controlling.
P.S. let's imagine the same situation in Denver Int. with LVO and RVR 300 ft. equal to approximately 91 m. There's no doubt only 2 are required and NO 90 meters visual segment will be visible from the flight deck, I'm afraid. Happily will I take off without TDZ RVR available and land 10 hours later in EU OPS land.
Last edited by 9.G; 13th Apr 2011 at 10:30.
Very interesting discussion. I began reading this a few days ago and started in the "can't do pilot assessment" camp but having done some reading of the relevant documents and re-read the thread my opinion has changed.
Totally agree with this statement.
The section (paragraph 3) that deals with take-off RVR says in Note 4 that the reported RVR can be replaced by pilot assessment. The next paragraph lists EXCEPTIONS to paragraph 3 and those exceptions do not include a statement prohibiting pilot assessment simply a list of additional requirements for take-off below 150m. As stated above you would need to see 8 lights (type dependent) with 15m spacing to achieve 125m RVR.
We know that thick fog can be variable over quite small distances which is why the 90m segment requirement exists. You must have >125m AND a 90m segment before take-off, if you are given say 135,135,150 but you cannot see 6 lights you can't depart. Similarly, in my opinion, if you were given 100,125,125 but could see 10 lights out of the flightdeck you could depart quite legally. The rules simply state that the required RVR be achieved for all relevant points.
Of course individual airline managers may have interpreted this differently or perhaps don't wish their crews to assess the RVR in those circumstances and put a statement in forbidding the practice. Once that manual is approved it becomes the law for that operator but as far as I can see there is nothing in the raw regulations to stop you doing it.
there is nothing in anything quoted above that specifically FORBIDS pilot assessment
The section (paragraph 3) that deals with take-off RVR says in Note 4 that the reported RVR can be replaced by pilot assessment. The next paragraph lists EXCEPTIONS to paragraph 3 and those exceptions do not include a statement prohibiting pilot assessment simply a list of additional requirements for take-off below 150m. As stated above you would need to see 8 lights (type dependent) with 15m spacing to achieve 125m RVR.
We know that thick fog can be variable over quite small distances which is why the 90m segment requirement exists. You must have >125m AND a 90m segment before take-off, if you are given say 135,135,150 but you cannot see 6 lights you can't depart. Similarly, in my opinion, if you were given 100,125,125 but could see 10 lights out of the flightdeck you could depart quite legally. The rules simply state that the required RVR be achieved for all relevant points.
Of course individual airline managers may have interpreted this differently or perhaps don't wish their crews to assess the RVR in those circumstances and put a statement in forbidding the practice. Once that manual is approved it becomes the law for that operator but as far as I can see there is nothing in the raw regulations to stop you doing it.
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well, perhaps a better understanding of RVR concept might bring some clarity into the pilots assessment. Let's start with definitions:
ICAO definition:
FAA definition:
So far so good, what does it mean in practical terms? Well, nothing else but RVR can be assessed by a observer in the EU OPS land at least. The logical question is if a human observer can assess RVR why can't a pilot do so? 
Well, please don't tell me coz we're superlative beings.
ICAO definition:
Runway Visual Range (RVR) — The range over which the pilot of an aircraft on the centerline of a runway can see the runway surface markings or the lights delineating the runway or identifying its centerline.
Runway Visual Range (RVR) — An instrumentally derived value, based on standard calibrations, that represents the horizontal distance a pilot will see down the runway from the approach end; it is based on the sighting of either high intensity runway lights or on the visual contrast of other targets whichever yields the greater visual range. RVR, in contrast to prevailing or runway visibility, is based on what a pilot in a moving aircraft should see looking down the runway. RVR is horizontal visual range, not slant visual range. It is based on the measurement of a transmissometer made near the touchdown point of the instrument runway and is reported in hundreds of feet. RVR is used in lieu of RVV and/or prevailing visibility in determining minimums for a particular runway.
1.
Touchdown RVR — The RVR visibility readout values obtained from RVR equipment serving the runway touchdown zone.
2.
Mid-RVR — The RVR readout values obtained from RVR equipment located midfield of the runway.
3.
Rollout RVR — The RVR readout values obtained from RVR equipment located nearest the rollout end of the runway.
1.
Touchdown RVR — The RVR visibility readout values obtained from RVR equipment serving the runway touchdown zone.
2.
Mid-RVR — The RVR readout values obtained from RVR equipment located midfield of the runway.
3.
Rollout RVR — The RVR readout values obtained from RVR equipment located nearest the rollout end of the runway.
Well, please don't tell me coz we're superlative beings.
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Originally Posted by 9.G
So far so good
Still puzzled by this reference to '8 lights' I keep 'seeing'.
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BOAC, I didn't suggest otherwise. I said only 2 are required and it's clearly depicted on the chart therefor no need to assess anything.
It's 6 CL in my opinion.
P.S. it must be noted as well among the conditions which must be met, one is related to the aircraft type. A visual segment of 90m is required from the cockpit during the takeoff run with the minimum RVR. All airbus models comply with this requirement with RVR of 125 m. In other words if I see a visual segment of 90 m from the flight deck I have 125 RVR assessed by the PIC. Same same if you ask me.
It's 6 CL in my opinion.
P.S. it must be noted as well among the conditions which must be met, one is related to the aircraft type. A visual segment of 90m is required from the cockpit during the takeoff run with the minimum RVR. All airbus models comply with this requirement with RVR of 125 m. In other words if I see a visual segment of 90 m from the flight deck I have 125 RVR assessed by the PIC. Same same if you ask me.
Last edited by 9.G; 13th Apr 2011 at 12:49.
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Max Angle, the exceptions are paras 4 (i) and 4 (ii) which allow you in 4(i) to operate down to 125m and 4(ii) down to 75m.
In order to achieve those exceptions you must comply with the terms included within those references as it says . It does not give you any exemption other than operating to a lower RVR.
In order to achieve those exceptions you must comply with the terms included within those references as it says . It does not give you any exemption other than operating to a lower RVR.
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With such a typically poorly worded document we will get absolutely nowhere chewing the cud on this one. It is my firm belief that the intent is to have TD RVR mandated as 'Reported' for 125/75m, but as with many things aviation it has been left unclear due to 'RVR' being undefined in the context. It appears to be left to Ops inspectors/regulatory authorities/companies/day of the week/size of in tray/state of domestic harmony etc etc to accept or reject manuals or make a ruling
Anyone needing a hard and fast ruling needs to get it in writing from their company - good luck.
Anyone needing a hard and fast ruling needs to get it in writing from their company - good luck.
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As this post was asking about company interpretations, my company happens to agree with the opinions of Torque 2 and Noak. That is, no pilot assessment below 150m. Just the requirement for a 90m visual segment. My personal opinion also happens to agree with that (however no one was asking me 
)
Max Angle, I see where you are coming from re "nothing disallowing" it but I am tending to go with the "nothing allowing it" reasoning. This is because to operate below 150m we have to train specifically for Low Vis procedures and it all becomes a lot more regulated.
I have to agree it is an interesting and tricky interpretation.
)Max Angle, I see where you are coming from re "nothing disallowing" it but I am tending to go with the "nothing allowing it" reasoning. This is because to operate below 150m we have to train specifically for Low Vis procedures and it all becomes a lot more regulated.
I have to agree it is an interesting and tricky interpretation.
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here's my question: LVO in force and TDZ RVR reported being inoperative.
scenario 1- following reports X/150/150
scenario 2- following reports X/125/125
in which of the cases is it legitimate to depart and if so under which conditions? To be more specific if X in scenario 1 is to be replaced by pilot's assessment which value are we looking for?
scenario 1- following reports X/150/150
scenario 2- following reports X/125/125
in which of the cases is it legitimate to depart and if so under which conditions? To be more specific if X in scenario 1 is to be replaced by pilot's assessment which value are we looking for?
Only half a speed-brake
Key point we all missed so far!
Debate revolves around "pilot assesment" but "replacement" should have been the issue.
Under your scenario, there is no replacement of reported RVR, no RVR is reported.
xxx/125/125 - count 8 lights and fly (if certified for 125 m ops)
> required RVR is obtained in all parts as required by EU OPS
xxx/150/150 - count 8 lights and fly (if certified for 125 m ops)
> required RVR is obtained in all parts as required by EU OPS
xxx/150/150 - count 10 lights and fly (certified for 150 m ops only)
> required RVR is obtained in all parts as required by EU OPS
more from top of my head:
125/150/150 - count 10 lights and fly (certified for 150 m ops only)
> first REPORTED value is REPLACED by pilot assesment, for 150m and more this is allowed
100/125/125 - no go (if certified for 125 m ops)
> under specific additional rules for 125 m ops, RVR must be achieved but pilot replacement of reported RVR is no longer an option
patchy fog, 200/800/2000, pilot can see down the runway - fly (no LVTO approval)
> first REPORTED value is REPLACED by pilot assesment, for 150m and more this is allowed
patchy fog, 150/125/125, pilot can see 4 lights only - no go (if certified for 125 m ops)
> condition of visual 90 m segment not met.
Opinions pls?
FD (the un-real)
Debate revolves around "pilot assesment" but "replacement" should have been the issue.
Under your scenario, there is no replacement of reported RVR, no RVR is reported.
xxx/125/125 - count 8 lights and fly (if certified for 125 m ops)
> required RVR is obtained in all parts as required by EU OPS
xxx/150/150 - count 8 lights and fly (if certified for 125 m ops)
> required RVR is obtained in all parts as required by EU OPS
xxx/150/150 - count 10 lights and fly (certified for 150 m ops only)
> required RVR is obtained in all parts as required by EU OPS
more from top of my head:
125/150/150 - count 10 lights and fly (certified for 150 m ops only)
> first REPORTED value is REPLACED by pilot assesment, for 150m and more this is allowed
100/125/125 - no go (if certified for 125 m ops)
> under specific additional rules for 125 m ops, RVR must be achieved but pilot replacement of reported RVR is no longer an option
patchy fog, 200/800/2000, pilot can see down the runway - fly (no LVTO approval)
> first REPORTED value is REPLACED by pilot assesment, for 150m and more this is allowed
patchy fog, 150/125/125, pilot can see 4 lights only - no go (if certified for 125 m ops)
> condition of visual 90 m segment not met.
Opinions pls?
FD (the un-real)
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Gets interesting, doesn't it? All through lax wording.
FD - I am uncertain about 3) "(no LVTO approval)" - I would suggest the min RVR of 400m would apply and if RVR is actually 'reported' at 200 that is a no go?
FD - I am uncertain about 3) "(no LVTO approval)" - I would suggest the min RVR of 400m would apply and if RVR is actually 'reported' at 200 that is a no go?