LVPs

[MaxReheat]

Given that LVPs can be in force even though CAT1 conditions still exist, is it permissible for crews not LVP qualified to operate into and out of the airport? Any pointers to 'official' references appreciated.

[BOAC]

My feeling is that you are confusing 'LVP' with 'AWOPS'?

If the wx is Cat I or above my understanding is that the imposition of LVP is just a means of controlling the slower landing rates, and being 'ready' if the vis goes below CAT I? All you need to do as a 'non-AWOPS' qualified pilot would be to conform to any 'LVP' published for the airfiled.

Over to the experts.

[HEATHROW DIRECTOR]

<<that the imposition of LVP is just a means of controlling the slower landing rates>>

Hey hold on BOAC; that's a bit misleading!

I'm nowhere near being an "expert" but LVPs are simply procedures followed by aerodrome operators and ATC to provide enhanced protection of landing aids during bad weather ops. LVPs are introduced as RVR or cloud base reduce to prepare for aircraft operations in very low visibility. They are not per se a means of, or a method for controlling landing rates. The reduction in landing rate at some airfields results from the necessity to provide greater protection of the ILS. On the ground LVPs involve the implementation of Ground Safeguarding Procedures to ensure the integrity of the ILS, ensuring that adequate lighting is displayed and the system for IRVR measurement is operational, etc.

LVPs have nothing to with which crews may operate; this is down to the operating companies based on the met conditions prevailing.

[standbyils]

The initial question posted here is a good one.

There are 'grey' areas surrounding this. The 'answers' I feel are not that helpful or accurate (BOAC). If you want a straight answer then I believe that you can operate as a non-qualified crew if the actual conditions are CAT1 or better.

For an approach all you need is the relevant VIS. For a take-off JAR suggests that you need to be qualified with a VIS of less than 400m. This is slightly misleading as I believe a CAT1 crew can take-off in VIS of 150m. The airfield is required to implement safe guards when the VIS drops below 400m in order to allow movements. A low-vis qualified crew can take-off in 125m with state approval. After the initial training (ground/simulator) has been completed you can usually make an approach in VIS below CAT1 after one practice 'on-line' (depending on the sim used for initial training), otherwise after 3. For take-off you are immediately qualified.

[MaxReheat]

standbyils

Thanks for the reply. It is the 'greyness' which prompted the question particularly with reference to the departure phase. LVP training in the sim includes the ground elements eg taxiing in low viz, conduct of checks, verification of centreline orientation and rejected take-off. A non-low viz trained crew will not have had the requisite training and therefore I pose the question again - can a crew that has received no low viz training operate at an airport that has officially sanctioned LVPs. Many airport LVP write-ups state that crews must be 'suitably qualified'. What, for example, would the repurcussions be if aforementioned crew rolled off a taxiway in 125m viz or had a runway incursion?

[mad_jock]

I thought that LVP's were very specific to individual airports.

Ie with these new mega high towers the airport can be in to LVP's and no RVR's being reported because the cloud is broken at 100ft and the tower can't see the runway. LVP's as such are purely a operating condition of the airport and as such have no bearing on the crew. Even if the mins are below the CAT 1 mins there is nothing stoping a crew taxing the aircraft to the hanger in 75m viz.

By holding a IR for the particular type you are deemed suitably qualified to operate that aircraft down to the minimums specified by the rating other wise they would set the minimums for that rating higher.

And there are alot of companys out there who are operating cat 1 machines and crew that SOP's allow them to do a min RVR CAT 1 departure.

MJ

[HEATHROW DIRECTOR]

More confusion....

<<The airfield is required to implement safe guards when the VIS drops below 400m in order to allow movements.>>

No, it's 600m. ATC decides when to implement LVPs and the criteria for commencing LVPs are as follows:

The IRVR (or meteorological visibility if the IRVR system is unserviceable) is less than 600 metres; the IRVR to be used to determine the commencement of these procedures is the TOUCHDOWN reading. If this position is unserviceable the MID-POINT reading is to be used instead;

OR

The cloud ceiling is 200ft or less;

irrespective of the serviceability state of the ILS, lighting, standby power etc.

Mad_jock said: "with these new mega high towers the airport can be in to LVP's and no RVR's being reported because the cloud is broken at 100ft and the tower can't see the runway."

Don't understand you Jock... The height of the control tower is irrelevant to LVPs as RVRs are measured at the runway and cloud is measured from the ground. At many airports RVR is measured automatically and the only ATC involvement is in reading the measurements to pilots.

[mad_jock]

I have maybe got my head round the wrong way with LVP's but some airports will put them in outside that critiria.

For example tower is on the otherside of the runway and the viz drops below a value that they can't see the apron area / taxi ways on the far side. They don't have ground radar so they don't know whats going on either the apron or the taxi ways.

I presumed the LVP critira was a part 2 thing with local equipment / georgraphy being taken into account.

BUt if not you learn something new.

[HEATHROW DIRECTOR]

<<For example tower is on the otherside of the runway and the viz drops below a value that they can't see the apron area / taxi ways on the far side. They don't have ground radar so they don't know whats going on either the apron or the taxi ways.

I presumed the LVP critira was a part 2 thing with local equipment / georgraphy being taken into account.>>

I am not aware of any UK airfield where such procedures exist but would be glad to hear.. LVPs are a designated procedure concerned with protecting the ILS for landings in very low visibility. There are a number of airfields where parts of the manouevring area cannot be seen in broad daylight, let alone in poor vis and Heathrow is one of them.

[fly bhoy]

HD

The height of the control tower is irrelevant to LVPs

Not entirely correct. As you quite rightly say, the implementation of LVPs is either at an RVR value OR a cloud ceiling, the key word being "or". Its very possible to have RVR readings in excess of 1500m, but cloud at about 150ft, hence LVPs based on Cloud and not RVR would be initiated.

I think the problems Mad Jock refers to arise if the tower is above 200ft tall, because by the book, you don't have to be in LVPs until the cloud ceiling drops to 200ft. If, however, your tower is, say, 250ft tall, you could be in the cloud, but LVPs wouldn't have to be initiated...by the book. I think that the MATS pt2 would be rewritten to increase the cloud ceiling values for LVP initiation prior to moving into a taller tower though, or it could be quite embarrassing!!!!:{

FB:ok:

[Turn It Off]

LVPS are determined by individual airfield requirements.

In cap 168 it defines three stages of visibilities. They do not apply to all airfields, some stages can be skipped.

The basis of these levels depends on the equipment at the airfield, Cat 1, 2, or 3 ILS, the correct lighting to supplement all of these categories.

I cannot rememeber word for word but simply put the stages are

1 - The visibility condition when the controller cannot see the aircraft. Useage of SMR etc is allowed

2 - The visibility condition where pilots have limited visibility and visibility decreases the ability for a pilot to seperate themselves from other on the ground.

3 - Really bad vis but I Cant rememeber the criteria!!!

As an example, at Cardiff, we do not have any means other than mark 1 eye ball for seperating aircraft on the ground. Therefore, it is deemed that visibility condition 1 exists when you cannot see both ends of the runway (1500M) so that is when we commence LVPS. (Safeguarding commences before this time).

Heathrow, and many other uk airports have SMR to assist them in seperation on the ground, therefore, they have reduced the minimium criteria before it is deemed that Visibility 1 exists.

Hope that helps, although it is a little vague. Im off to read about snow now!!!

TIO

[HEATHROW DIRECTOR]

Turn it off.... Very many thanks for all that. I downloaded CAP168 and read up on LVPs. I'd never heard all that before; s'pose I was too mollycoddled at Heathrow!

[NudgingSteel]

ATC Low Vis Procedures are designed to protect the ILS signal so that aircraft can make approaches down to CAT2 or 3 minima (depending upon the airport ILS, lighting etc etc). They exist so that crews can be secure in the certain knowledge that when they are flying a (probably autoland) approach down to absolute CAT2 or 3 minima, the signal can be utterly relied upon. From the flight deck perspective, it doesn't really matter whether the tower is in the cloud or not. Regardless of whether the vis is 150m, or 5km underneath a 100' overcast, we still have to apply the same protection to the ILS signal.
HD is spot on; the flight crews will know what their minima are, dependant upon aircraft equipment levels, crew certification etc etc, so it's entirely a company matter if they can operate into an airport or not given any prevailing met conditions. LVPs may be instigated by ATC at various trigger points (but must be in place at certain vis or cloud levels) , so I doubt that 'LVPs in force' is concrete enough for comapnies to base operating decisions on.

[mad_jock]

h'mm nudge in that case you wouldn't have LVP's at cat 1 airports. LVP's are purely to stop us banging into each other and blaming ATC on the ground in a basic sense and to add protection to fancy stuff in the added value issues.

But having a look at the books it turns out that you only need a special endorsment / equipment for the arrival. It doesn't matter what you have done in the matter of training to cat II or cat 3 level your departure limits are the same for all crews with an IR( unless of course you are single crew but i take it we can forget that one seeing as i think we are talking about multi crew ops)

There is no min taxi limits for the crew, commanders "**** that card" unless ATc refuse to give a taxi clearance.

LVP's to me at a CAT 1 airport with no ground radar are only a proc method of seperating aircraft on the ground. Ie one aircraft in an area with a clearance limit to the next area. Because the controller has no other method of seprating them.

LVP's i still think have nothing to do with flight crew only how the airport manages the aircraft. Its a controlers problem to meet there limits for seperation not the flight crews. If the limits for the plates are 125m's and all the equipment is available ie center line lighting etc. You can go.

BTW I know that Cat 2 and 3 trained guys are taught to use the localiser for runway alignment on departure. I hadn't heard of this until a pub conversation. But there is no requirement for the localsiser to be functioning for a min RVR departure. There might be in your SOP's but there is nothing on paper in either JAR ops or ANO. So there might be the situation that pilots with no CATII/III training are allowed to depart in 150m viz and the Cat 2 and 3 pilots have to stay because the localiser is tits up all due to the SOP's.

And yes I haven't ever done any special low vis ops procedural training as per say apart from the standard type rating and yes I have departed a few times at near on RVR limits for departure which were well below CAT 1 landing mins.

MJ

[slink]

When we know that the weather is deteriorating, we'll initially go to safeguards, which don't alter the aircraft operations, but do alter our operations. At the airport we have a number of vehicles which can drive around without talking to ATC. As these vehicles could be inside areas deemed to infringe the LSA (Localiser Sensitive Area - a square box from the localiser antenna all the way down the runway, at 137M either side of the centreline), Safeguards cancel their freeranging privileges and mean they need to ask permission from ATC to enter the airfield. It also suspends any non essential work etc, so ATC know exactly who, what and where is on the airfield. I believe Scottish are also informed at this point, as it's possible that flow control will need to be applied if the weather deteriorates further.

If the weather does then continue to deteriorate, to a touchdown IRVR of 600M or less, or a cloud ceiling of 200 feet or less, then we go into LVPs. At this point, we use the CAT III holding points (positioned outside the LSA mentioned area), and ensure there are no vehicles at any point on the airfield that may infringe the LSA. We also are not allowed to use intermediate runway entry/exit points, so everything goes on at the end, and vacates at the end. This changes our procedures to need 10 mile spacing between inbounds (I bet that sends a shiver down HD's spine!), as any arrival needs longer to vacate (all the way to the end), and any departure has to be past the localiser antenna before we can issue a landing clearance, which needs to be issued at 2 miles (or at the absolute latest 1 mile with a late landing clearance). If the weather deteriorates to 100M or less, we can only allow one aircraft to taxi at a time!

In any of this, there was no change when we moved to the new tower, and we do have SMR covering the airfield, and as far as pilot qualifications are concerned, we neither know nor care. We give the visiblity and RVR information, it is up to the crew to know whether they exceed their minima or not.

At times, when we know we have patchy fog etc., it is possible for us to be in LVPs, but be above the LVP minima (if we suspect it to get worse again - there is nothing worse than continuously going in and out of LVPs), so at that point, I guess a pilot who has a minima requirement above that for LVPs could use the airport, as the current conditions would exceed his requirements, but that bit I am not totally sure about...

[terrain safe]

When people are saying that LVPs are used when the 250 foot tower is in the clouds and can't see the ground, they actually mean a 'weather standby'. this is when the fire station crews are not allowed to leave the building so that if there is an incident they can be rolling to the scene quickly. Also used in strong x- winds. The only reason an a/c needs to know whether LVPs are in force is to confirm that the runway is safeguarded.

[Miles Magister]

The JAROPS 1 definition of a LVP take off is when the RVR drops below 400m.

Each airfield may impose their own criteria which will will be detailed in their own MATS part 1. This should also be reproduced in the national AIP. These are normally straight out of CAP 168 but this is only a recomendation based on ICAO annex 6 which is in itself a recomendation, not legislation.

When operating to foreign airfields crews should check the relevant national AIP as there are national variations. For instance the Italians specify that when the airfield declares Cat II/III operations both aircraft and crews must be suitably qualified even if actual conditions are inside Cat I limits. This is stipulated in their AIP and I only discovered it after landing at an airfield which had declared Cat II in Cat I conditions. I was lucky enough to receive a free quality check of both personal, company and aircraft documents!!

The JAR-OPS rules are included in JAROPS 1.440 to 1.460 and their appendices, including the traiing requirements. They are too large to paste here but can be viewed online from the JAA web site.

For private Ops the airfield/national rules apply.

What ever you do, do it carefully!!

MM

[yakkity yak]

I will second that last statement, what ever you do do it safely

[standbyils]

Heathrow Director,

If you didn't manage to implement LVPs in time (600m) and the RVR dropped to 450m could you allow take-offs to happen?
i.e. Visibilty of 400m or greater does not represent a LVTO under JAR-OPS

[HEATHROW DIRECTOR]

standbyils.. ATC cannot refuse a departure and I recall that operations could continue provided the pilot was advised. An example would be an unserviceability of the IRVR system. In that case the Met visibility is passed - and that can be quite different to the IRVR.

Hopefully someone current can provide you with a definitive answer..

[standbyils]

Heathrow Director,

Then my next question would be what if the RVR dropped below 400m with no LVPs in force? Can crew depart? Can the airfield process departing traffic?

You corrected my earlier post (and I'm all for being corrected!), but I was answering the original question posted from a legal stance (JAR-OPS/FCL). I believe your correction to my answer to be based on local procedures and protocols for dealing with the likelyhood of LVPs being required as RVR drops (departing and arriving traffic).

In short, to answer the original question, a non-qualified (CAT1) crew can take-off down to 150m (LVPs being in force). Right or wrong? It was my impression that without LVPs the lowest RVR for take-off is 400m (regardless of crew qualification- Cat1/2/3 etc).

[ATCbabe]

Standbyils

Then my next question would be what if the RVR dropped below 400m with no LVPs in force? Can crew depart? Can the airfield process departing traffic?


Just to clarify a few things,

1) If the rvr drops to 400m then we are in LVPs no matter what.

2) The crucial thing here is whether or not the runway is safeguarded. If not then all pilots will be told that "ATC LVP's are in force but the runway is not safeguarded" It is then up to a pilot wether or not to land/depart depending on what his/her criteria is.

3) It is not a factor as to how high a tower is. It is just weird tho looking down from a tall tower to see clouds below!!

Babe

[standbyils]

In that case my original post was correct. By the way, pilots are not allowed to factor Met Vis for a Cat 2/3 approach (or LVTO, but I can't remember without looking whether that applies to LVTO below 400m or 150m).

[NudgingSteel]

ATCbabe, just have to pick you up on one thing....

"if the rvr drops to 400m then we are in LVPs no matter what"

Not necessarily! Yes, you certainly should be using LVPs by that point but the 'P' stands for 'Procedures'. If you've forgotten to get the safeguarding done in time, or you've inadvertently taxied someone to the Cat1 hold (or they were holding there as the RVR dropped right down )etc etc, then you're not protecting the LSA and therefore you're not carrying out Low Vis Procedures.
At which point you have to use that appalling phrase "RVR 400m, the ILS is not protected" !!!!!!

[ATCbabe]

Nudging,

As always you are correct. Sorry its the way I phrased it.
What I should of said was that we are in low vis and as such treat it as LVP conditions, as much as we can, even when not safeguarded.

[mad_jock]

I take it most of you work at airfields with all the wizz bang kit for telling you were things are when you can't see them.

What happens if your ground radar, wet bit of sea weed or what ever method you use to seperate the aircraft fails when you can't see the manovering area / active runway.

And I would say its all up to your SOP's standbyils. If the crews wern't allowed to do a 150m rvr departure the A1 would state that. And if the CAA decided that cat 1 crews wern't allowed to operate in RVR's down to 150m. The A1 wouldn't be approved until it stated that you couldn't. If the airport wasn't qualified for CAT 1 crews to depart from with the minimum RVR it would have an extra limitation in the departure minimums table. So if the SOP's say you can its Right.

I would imagine a very large percentage of turboprops/crew in the UK are CAT 1 only. Only difference is we are a bit more restricted with departure finding a departure alternate. Which with the UK's wx would be the more limiting factor than the local wx conditions.

MJ