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Diversion to a LVP alternate

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Diversion to a LVP alternate

Old 4th Dec 2021, 16:58
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Diversion to a LVP alternate

Hi guys,

chatting with some colleagues, we came up with a discussion about diverting to an alternate which is in LVP conditions above your minimums (It just started to be LVPs, from 5000mt down to 2000mt and then RVR around 500mt, CAT IIIA available, CAT IIIA aircraft, no MELs, Fuel extra 20 mins on top of FIN RES once at the alternate) considering that it's the best Commercial alternate for that destination, while the second option is not in LVPs, slightly further away, still with 10-15 mins holding on top of FIN RES at the alternate.
Different opinions arose so I'd like to know what do you think about this without conditioning the answers with what they said
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Old 4th Dec 2021, 17:19
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Hold at your destination until you haven't got enough fuel for your second alternate and go to the first alternate.
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Old 4th Dec 2021, 17:28
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What is LVP?
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Old 4th Dec 2021, 17:39
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This is a Professional Pilot forum we know what LVP means
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Old 4th Dec 2021, 18:16
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It's actually a regional thing, "Low Visibility Procedures" is not generally used in the US. We just say Cat II, III, etc. Sometimes "Lowered Landing Minimums." Only reason I know it is because of PPRUNE.
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Old 4th Dec 2021, 18:33
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IMHO, no. I would be headed for the alternate with better weather and screw the "better commercial alternate". All airports have a drastic drop in traffic flow when LVP's are declared. I would imagine with the queues building up(depending where you are), a low fuel arrival that has to jump the queue would not be a welcome addition to the ATC burden. Then we need to consider whether an Autoland is required. If this is required then it is not a good idea to commit to an airport where a single failure can remove your Autoland capability(on airbus a flaps locked will reduce you to Cat 1). Arguably you could pull off a manual landing with 500m but I certainly won't be trying it. Accidents are regularly a function of having incrementally having painted yourself into a corner for the company benefit, just go for the better weather.
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Old 4th Dec 2021, 19:52
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You donít of course have to divert to the filed alternate. I can remember Venice being below Cat 3A weather and ending up in Bologna. The filed alternates were Trieste which was enjoying the same coastal fog as Venice and Klagenfurt which required special sim training (which in my case had expired). I called ops from the briefing room in advance about this and was told to take as much fuel as I could and use my best judgement where to go, which after about 90 minutes holding at Chioggia is what I did. Not as radical as an Easy I was behind in Pristina who on going missed reported he was diverting back to Zurich where he had started. Ironically I actually saw the lights at MDA and got in. Topswiss did not reappear so presumably returned to base. These days with Acars you normally get pretty clear directions from Ops what they would like.

Last edited by lederhosen; 4th Dec 2021 at 20:09.
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Old 4th Dec 2021, 22:39
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There is a lot of useful information in the ICAO Flight Planning and Fuel Management Doc 9976 and there are also draft EASA docs on the net which attempt to mirror and expand on what ICAO are saying. Airline policies tend to be based on these documents but I don't think the training world has caught up with the 100+ pages of tech jargon. My basic understanding is that once airborne, the Commander's responsibility is to use all available information to manage fuel/energy to make a safe landing at a suitable aerodrome with Final Reserve Fuel remaining. The word safe seems to imply that there could be a less safe option and this would by default become applicable once the MAYDAY fuel call has been made or if committed to a particular airfield and stuck with having to land below minima. An unintended diversion to a military airfield is also classed as less than safe but it is in the controllers toolbox once it looks like Mayday fuels calls are a possibility. Why not consider Waddington for BHX or EMA say, if it is open and if there are problems and several Min fuel calls on freq?

There doesn't seem to be any reference to requiring a higher minima approach as per the planning rules so diverting to cat 2/3 is probably OK but perhaps not wise. Personally, I would go with the planning minima because as mentioned, many the other things that can go wrong which would preclude a certain approach are not likely to become apparent until on approach (flaps stuck?).

These documents do refer to the fact that it is far easier these days for pilots to gather information from other sources other than ATC so it should be possible to involve Ops with decision making but having looked at these docs, I can see how you got several different answers and why one ops controller might offer completely different advice than another.

In the scenario you mention, you have effectively committed and most ops manuals tend to describe the scenario of committing and lay down criteria, even if they don't actually call it that. I think most ops manuals require one lower level of minima (cat 1 for expected cat 2/3) for "committing" so I would probably use that in my justification.
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Old 5th Dec 2021, 00:24
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Go somewhere safe. Had to reject several planned (computer) alternates chosen by cold, impractical and technically legal rules by algorithms. Any tech failure worth talking about and you're Cat 1. You work for an organisation founded by company documents and filings and probably run by accountants. The 150-300 people behind you have lives to live and loved ones. Enough said.
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Old 5th Dec 2021, 06:41
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Legally you can do it. Is it the safest option? No. Probably not.
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Old 5th Dec 2021, 07:38
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Part of the problem in this sort of scenario is that airport ops managers (sitting in cosy offices) risk asses everything to death and are driven by the accountants. Making their airfield available for diversions depends on things like stands and handling availability or simply whether there is enough profit to be made for the extra hassle. At the other end of the line, a Commander through company policy and unexpected changing circumstances can end up only a few minutes away for having to adapt from following the rules to doing what is necessary to save life.

I had a classic example of this once when three jets arrived in the hold at ABZ when the weather had fallen below limits and it was not forecast. Simultaneously, the controller put out a broadcast announcing that neither EDI, GLA or INV were accepting diversions. We all had plenty fuel but ended up having a bizarre RT conversation about exactly what did they want us to do then and when would it be convenient for these airports for us to say the "M" word. The controller quickly picked up on the point we were making and strangely, the three airports suddenly started taking diversions. This does highlight the disconnect in safety management between airline minimum fuel policies and the way ATC and Airfield ops think. The Drone incident at LGW and the Multiple pan / Maydays a couple of years ago when there was smoke in the atmosphere quickly start to show how easily things can start to break down when things go wrong on a large scale.
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Old 5th Dec 2021, 09:27
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Thank you for your opinions and insights guys

What I experienced a couple of years ago was something similar (diversion was executed due to unexpected fog (nothing on the TAF at all) at destination with ILS U/S that day) to my example except that, after having chosen the best weather alternate, second or third commercial option, I don't remember exactly, during the 20 min trip to that the visibility and RVR dropped quickly there too.
The TAF was giving this conditions later (something about 2-3 hours later) and the reports we had at the beginning of the diversion was good (something like 5000 mt and BKN 020).
We ended up conducting an autoland due to fog, something like 600 mt RVR and BKN 002 but at that time we couldn't change our plan.

I know it's "one of those days" where you can't actually count on precise weather forecast and we needed an autoland anyway, but what it surprised me was that others were going straight to the best commercial alternate even if it was already close to LVP activation (Low visibility procedures) at the start of the diversion.

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Old 5th Dec 2021, 15:57
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An understandable question - Low Visibility Procedure, an IR-Ops term (although Breakthesilence does not identify if he is in an area governed by IR-Ops) that it appears is being referred to based on the context of the original post. Here in FAA land, since they are never shy about making things as complex and confusing as possible the term used is LVO/SMGCS - Low Visibility Operations / Surface Movement Guidance and Control Systems. All well above my pay grade in all the professions I practice so my simple understanding is that these are added safety practices that allow surface movement in poor visibility conditions, departures for those that can meet the departure requirements, and landings which are limited primarily to aircraft that can perform Cat III approaches but if things are marginal you might squeak in a Cat II capable aircraft.

Or, maybe what a dyslexic person would call an LPV (Localizer Performance with Vertical Guidance) approach - OK just kidding, but have to give a nod to my fellow dyslexics. Watch out for clearance to land rwy 31 (or is that ...)
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Old 5th Dec 2021, 19:07
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It's much simpler in the UK, we don't need LPV's anymore so only have to worry about LVP's. Except being able to do LPV's in LVP's might be quite useful.
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Old 10th Dec 2021, 13:08
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A lot will come down to local knowledge of the airports and the way they tend to fog out. If I was confident that the alternate was not likely to deteriorate further I would be happy to proceed there. If I didnít have sufficient knowledge I would have a rock solid alternate up my sleeve.

In my experience forecasters are not able to forecast with sufficient accuracy whether the vis is going to drop to 400m or 40m and it only takes very small changes in the atmosphere to get either of those readings. Once I start seeing low dew point splits and light winds at this time of year in NW Europe, I start to become very conservative in my fuel planning.
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Old 11th Dec 2021, 10:59
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If I were to choose to fly to a Commercial Alternate that was going to have Low Vis Procedures in place then I would be most concerned about the additional holding and delays that would inevitably build up there!
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