EGGD this morning

[Bearcat]

Foggy there this morn...usual suspects landed first!

[Squealing Pig]

IOM foggy too, The point of the thread being......?

[Aranmore]

Nice morning in Toronto. A bit cold though! Who are the usual suspects, and why?

[Rwy in Sight]

Comment removed after carefull consideration of what BOAC wrote!


Rwy in Sight

EDIT: Unsupported allegations against any airline are totally unacceptable. If you have the pertinent RVR's for these 'alleged' breaches' please advise the CAA of Flight number and RVR at the time the aircraft passed the relevant point - otherwise SHUT UP!

[CAP509castaway]

I agree with squealing pig . Just because an aircraft lands at Bristol or the IOM it doesn't mean they are making an illegal approach. Last week at the Isle of Man the weather was 1250m we landed then an hour later it was down to 400m. ATC will not allow you to make an approach unless the vis is above the minima.:ok:

[EISN]

CAP509...

Your comments is completely and utterly incorrect...

ATC WILL allow you to fly any approach you wish, whether or not the vis meets the required minima. It is the commanders responsibility to enforce the approach ban.

Bear in mind also that different operators can have different minima for a given approach. For instance, LO VIS apporved operators can accept a 75m rollout in some cases, others need 125m etc...

Check your facts!

[CAP509castaway]

EISN,
You are quite correct , ATC will alow you to make an approach but they are also aware of the system minima and aircraft minima and would be contacting the CAA if you landed with the vis below your minima.

[Capt Pit Bull]

Here is a comment:

The fact that Danny has set up these forums, combined with the fact that freedom of speech is generally considered to be a good idea, gives people to ability to spread their opinions over a wide audience.

However, the fact that you CAN do something does not mean its a good idea.

I am afraid that for me, this is the straw that breaks the camels back. I have sat with my lips buttoned through countless threads over the last few years where people have attacked my profession with scant or more usually non existant evidence. Well, this is one step too far. I'm sick of it, and it needs to be stopped.

Here we have, not very thinly veiled, the implication made that certain airlines are acting improperly in regards to AWOPS.

Bearcat, lets spell it out. Please advise us of the RVRs reported at the time the aircraft in question passed the 1,000' point, and the AWOPS capability of the aircraft type in question.

If you don't know these numbers, I'd like to invite you to engage brain before putting fingers to keyboard and making disparaging comments about my profession.

Rwy in Sight. I sincerely hope the airlines you have just maligned sue you, and that pprune doesn't get caught in the cross fire. When I get a moment later today I'll be contacting them myself.

CPB

[CAP509castaway]

Hear ,hear Capt Pitbull.
Lets have facts not hidden inuendo:mad:

[flower]

As someone working in the area this morning I can assure you that IRVRs were up and down like a Yoyo before people start casting aspersions.

[No_Speed_Restriction]

especially last evening at cwl.

[almost professional]

if its CAT1 then you give the A/C in question the absolute minima for the apc, tell the pilot that he is in breach of legislation, there is no traffic reason to prevent his landing and reach for the 1261's-CAT2/3 then no requirement to monitor the minima-you assume that the A/C+crew are capable of the apc being used(at least that is how I understand the rules on absolute minima!)

[Ranger 1]

I have known aircraft land off a visual approach, when IRVRs have been given as 300m. Simple reason due to Shallow fog over the IRVR points, & the ATC tower was also in a bank of fog, but the runway was clear of Fog
(Aircraft was visual at 25 miles).
Problem was when it had taxied into the bank of fog, "Old muggins" here had to find it, & provide it with a Follow Me to the stand. :E

[BOAC]

Ranger - I've had that twice in my life, once in EDI when drizzle/spray on the IRVR machine gave 100m when it was CAVOK and in ABZ when blowing snow reduced the RVR to 150 m but we could see the runway from 30 miles - and 8 feet!

Can someone from ATC confirm please - I have been told that the only way I can land in those BROADCAST RVRs is if ATC declare the IRVR 'u/s' and pass met vis?

[benedictus]

From an ATC point of view:

If the commander of an aircraft elects to make an approach when the visibility is below the minima for that approach, we cannot stop them, we will however tell them that if they continue then the facts will be reported, if they elect to continue then they will be told of any known traffic to affect the approach, if there is no known traffic to affect the approach or landing then they will be told and the facts reported.

If they haven't got a darned good reason for electing to make an approach and land below the minima for such an approach then they will be hauled over the coals.

Many pilots elect to make approaches below minima in the hope of an improvement to above minima during the approach (irvr readings change so quickly it is possible that this can happen), all the professionals I have met and worked with have gone around when they have to if needs be, any pilot that elects to land below minima would be hauled over the coals unless they had a darned good reason for doing so.

[BOAC]

benedictus - if that reply was for me, can I reiterate that the question was

"when the visibility is REPORTED below the minima" - but there is an OBVIOUS fault in the measuring system and the visibility is OBVIOUSLY well above the minima?

What is the procedure to get a report that makes us 'legal'?

[benedictus]

BOAC,
My reply was not for anyone in particular.

Who determines if here is a fault?

Where I work, we often get rvr reading below minima because shallow fog is sitting on the transmissometers north of the runway, the runway itself is clear, however we in ATC are legally bound to report these readings even if the runway is clear and you have unlimited vis apart from the shallow fog over the daleks( affectionate name for the transmissometers).

We would still be in LVP's like it or not, and legally you would have to rely on those reports.

[Ranger 1]

We still have human observers in the form of Firefighters

:hmm: who can be called upon in case a possible IRVR fault, on the odd occaision the readings have been better:ok:

[BOAC]

Thanks Ranger - so, when it is blindingly obvious that the IRVR is wrong, is it up to me to ask for a fireman:D or will ATC recognise the problem and 'check' the reading? What problems (in a 'disciplinary' sense) would this give the controller?

In both the cases I quoted ATC seemed unable to do so. In the first, I was overflying a CAVOK EDI but the RVR stayed at 100m (until someone took a Kleenex to the lenses:D ), in the second I THINK ATC offered 'land at my discretion' and I landed at ABZ but the 'reported' RVR stayed at 150m althought the aerodrome was completely clear EXCEPT for the trannies. I was not sure whether I would be put in the 'Tower of London' and executed. I also diverted several years ago in a CAT I a/c to Manston from 08R at LGW when there was (300m) fog between the trannies but the whole of the approach and runway were clear.

For the benefit of 'Runway in sight' (what an appropriate name :D ) I am NOT suggesting we should bust any 'real' minima.

[fly bhoy]

As far as I can gather, absolute minima only apply to Cat I and localiser only approaches, and also SRA's.

So;

a) If the ILS is only radiating on Cat I and,
b) The RVR is showing below the absolute minima for the aerodrome but,
c) You can see the whole of the runway,

when the approach controller asks you to report your intentions and you reply you're visual with the runway and will continue visually, technically you're not breaking the rules.

I would however advise against this unless you are 100% visual and can see the whole of the runway for the whole of the approach, and not to use it just for the sake of getting round the laws!!;) Not that I'm saying anyone would think of doing that now!!;) :D

FB:ok:

[PPRuNe Radar]

I think this topic has moved on a bit since the initial 'spotter' type of post so have moved it here.

Keep the answers flowing !!!

[jayteeto]

I have just read the latest CAA incident bulletins and there are 2 airfields now reporting a number of airlines/operators for approaches in low visibility. will not name here in case I get told off, but the names are there for all to read and the visibilities for each incident are stated.

[salvation]

The whole issue of 'instant' IRVR can be a real pain in the ass.

The classic airfield for this is Birmingham, I believe their IRVR detectors are located in possibly the worst place on the airfield. I have lost count of the times we have seen the airfield from 20 miles out, they have, in the past, given the most ridiculous met of 10km, LVP's, IRVR 250,125,300 and we have maintained visual contact all the way down approach and rollout.

So, last night we were doubly inconvenienced as they have removed the centreline lights as part of the work in progress - hence, no CAT III, or CAT II below 550m :(

We did get in, legally, we had sufficient RVR up to the 4 mile point, we never lost sight of the runway even on short final where the alledged RVR dropped to unspeakable amounts.

So......................

Why can't the airport builders/maintainers and ATC people communicate and discuss such matters with 'the customers'. They would then appreciate that if you are going to use IRVR, it shouldn't be located in a boggy hollow that is the first place to fog out.

[BOAC]

jayteeto - could you oblige with a link to the CAA bulletins please? It will save a lot of searching:(

[Spitoon]

I don't think the incident bulletins are available on line but there's a CAA document (http://www.caa.co.uk/docs/33/ATS019.pdf) that describes the absolute minimum.

A couple of other things, few airports with IRVR still have the ability to offer human observer RVR.

As I understand it, and I speak as a simple controller, unless the IRVR equipment is reported as faulty by the engineers or is giving an error from its own diagnostics (and ATC report to a/c that it is u/s), the pilot cannot use and factor the met vis.

The visual approach business is interesting. Never been faced with a pilot electing to do a visual approach and I thought it was not permitted because of accidents 20 or 30 years ago where the poor slant visibility caught some pilots out. I'm sure there used to be something in the controllers' documents about absolute minima for visual approaches but I can't find it now. In the UK though, the ANO (articles 38 and 39) say that the aircraft can't go through 1000ft if the wx is below the minimum for the approach. Presumably there are minima for visual approaches and whether the pilot can see the runway or not, if the wx is below the minimum, the approach cannot be continued - or am I way off the mark here?

[almost professional]

salavation
the difficulty is that the transmitometers need to be alongside the runway-one in each third, yet clear of the strip-for obstacle clearance, putting them over grass-leading to problems with overreading-human observer method of course reads over the runway itself looking at the runway lights, much more likely to be accurate if the fireman is awake!-do not see any way round this problem, we suffer from both spiders in the lenses and moisture-but have to give the readings unless tels take it out of service

[fireflybob]

>Presumably there are minima for visual approaches and whether the pilot can see the runway or not, if the wx is below the minimum, the approach cannot be continued - or am I way off the mark here?>

Spitoon - you are quite right. Most company Ops Manuals specify that the touchdown RVR for the landing runway most be at least the (CAT I) RVR required for the instrument approach onto that runway if there is one. Also there are requirements for In Flight Vis whilst conducting the visual circuit depending on a/c Cat (eg C is, I believe, IFV 3,700 metres). Only the pilot can assess this latter aspect!

[salvation]

Why do we always work to 4 miles in our recurrent sims when this document refers to 1,000' - is this an old document ?

[TheOddOne]

The point about SRA is also interesting. The approach to LGW's Northern runway (08L/26R) is via an SRA initially, which is to 2 miles. Now, when conditions are marginal, it appears some companies aren't allowed to start an approach if reported conditions are below their minima, others are allowed to fly down to these and continue if they can see the approach lights. Thus, we lose some traffic but not all.

We do try to base our decision upon whether or not to cancel a night's maintenance and keep the main runway open on whether or not we're going to lose traffic, but obviosly we can't cater for just one operator when everyone else can make it in. It's interesting how these things can vary between operators, even of the same a/c type. However, in all cases, ATC will offer the SRA to whowever wants to make an approach.

BTW, when things are marginal, we study the short & long TAFs, have long conversations with the Aerodrome forecaster at Exeter (very helpful & knowledgable) but in the end it quite often comes down to our local knowledge and experience - cloud ceiling 700' or 900'? vis 2,500m or 3,000m? You're damned if you do, damned if you don't! It's great when you guess right, Yellow Pages down the trousers the following morning if you don't!!!

Cheers,
TheOddOne

[spekesoftly]

I'm sure there used to be something in the controllers' documents about absolute minima for visual approaches but I can't find it now. In the UK though, the ANO (articles 38 and 39) say that the aircraft can't go through 1000ft if the wx is below the minimum for the approach. Presumably there are minima for visual approaches and whether the pilot can see the runway or not, if the wx is below the minimum, the approach cannot be continued - or am I way off the mark here?

Spitoon,

If you scroll down to the last page of the CAA Document (http://www.caa.co.uk/docs/33/ATS019.pdf) link that you posted earlier, para 6 reads:-

"A value of 800 metres RVR is to be used at all airports as the Absolute Minimum for visual approaches"

[BOAC]

I'm not really sorry I dragged this away from where it started. (Tks Rwy in sight, BTW).

May I summarise my enquiry? It appears that no-one can over-rule an errant pair of 'daleks' UNLESS the Tels people can be persuaded to withdraw them, and they would, presumably, only do this if they were 'broken'? So we appear stuck with it.

[Spitoon]

Thanks speke - I guess I should have read it to the end!