Instrument approaches below minima

[NorthSouth]

Watched a Cirrus SR22 on FR24 earlier today make an approach to Wick on a flight from Reykjavik. Latest Wick METAR (10 mins before his approach) was 2000 BR OVC001. The next one (20 mins later) was 0350 FG OVC001. Lowest OCH for any procedures to runway 31 (assuming LPV not available) is 326ft. He made the approach and landed - all the while squawking 7000!
I'd be interested to know how such an approach might be flown, in practical terms. With vis of 2000m the approach ban probably doesn't apply, but how is it possible to complete a (presumably RNP) approach from breaking out of cloud at 100ft?

[Chesty Morgan]

Cloud base doesn't prevent an approach the visibility does. If the visibility is above the minimum for the approach you can fill your boots all day if you like.

[NorthSouth]

Originally Posted by Chesty Morgan

Cloud base doesn't prevent an approach the visibility does. If the visibility is above the minimum for the approach you can fill your boots all day if you like.

Not my question. What I'm interested in is the practicality, not the legality.

[Sleeve Wing]

Sounds like a transAtlantic flight, NS.
Nothing to prevent his approach with 2000m., either commercially .....or even as a private flight.
The cloudbase at the commercial DH would probably still allow the approach lights to be seen as a shape if not singly so lining up would be no problem for an experienced ferry pilot. The visibilty below cloud would also allow for a clear landing picture and centreline maintenance.

Practicality ? Why not ? Probably needed a pee ! No fuel problem with a Cirrus so no ill-considered approach.

[FullWings]

OVC001 in real weather is often not like OVC001 in the sim, especially when you’ve got bits of weather coming in from the sea. You might get enough of a visual reference at 2-300’ with a good lighting system, depending on the opacity of the cloud. At that height, it’s unusual to get an unbroken sharp layer; also, that’s a met observation with the usual tolerances, and is only representative of what you might find, not what’s actually there...

[jmmoric]

There are a few things to consider when reading a METAR.

A METAR is updated in intervals, meaning the cloudbase has to hit certain "steps" before a SPECI is issued, and if the METAR is sent regularly..... you won´t even see a SPECI anymore. Updates to improvements rewuires the improvement to stay for a while before being reported, whereas deteriorations will be given straight away.

What you get from a METAR is based on the value overhead the airport itself, and with automation, that would be overhead the cielometer exactly....

[dont overfil]

Originally Posted by NorthSouth

Not my question. What I'm interested in is the practicality, not the legality.

synthetic vision?

[43Inches]

What you get from a METAR is based on the value overhead the airport itself, and with automation, that would be overhead the cielometer exactly....

Cielometers can be a bit iffy in low visibility as well, without an 'actual' report validation. If it was an automated ceiling reading I just take it as general advice, the pilot always makes the final judgement on what they can see at the minima and their actions, without a camera on board during the approach you'd have no chance proving they were legal or not wrt cloud base.

[S-Works]

Only the pilot knows what they saw out the window at DH…

[parkfell]

This sounds like one of those Q where there is a disconnect between what might be asked during initial groundschool and the practicalities of flying an approach with the external visual reference only being acquired at DA/H, as the cloud base on short final can “ebb and flow”.

The cloud measurement occurs at a specific time. It is not like the simulator where that precise cloud base can be achieved and remains constant.

Only when you have experienced these marginal conditions over time, does the osmosis start to occur and you appreciate the theory from practice.

[jmmoric]

Originally Posted by 43Inches

Cielometers can be a bit iffy in low visibility as well, without an 'actual' report validation. If it was an automated ceiling reading I just take it as general advice, the pilot always makes the final judgement on what they can see at the minima and their actions, without a camera on board during the approach you'd have no chance proving they were legal or not wrt cloud base.

Exactly, and the general rule now is that having automation doing the observations is good enough. You don't need anyone to verify anything once auto-observation equipment is installed.

[Genghis the Engineer]

Well I'd argue that he should have been squawking 2000, but other than that it's the cloudbase experienced by the pilot that matters, not what was most recently reported by the ATIS. If he saw two lights by the DH, and judged visibility remained adequate, he was totally within his legal and practical rights to land.

The practicalities are simple enough: he should have continued to DH, if he saw two lights he was within rights to land - with standard practice being to level for a short period in case things come together whilst over the runway. If he didn't at DH, he should have flown the missed approach procedure and either diverted or had another go. No different to better or worse conditions really.

G

[jmmoric]

Originally Posted by Genghis the Engineer

- with standard practice being to level for a short period in case things come together whilst over the runway.

We're still talking about the LNAV here. Then it's correct that you stay in the MDA(H) until the missed approach point. But if you mix DA(H) into it, you mess it up.