For example, there is no way to legally land at Bournemouth EGHH if the ATC-reported RVR is below the pilot or below the approach plate minimum.
The pilot minimum is about 550m or 850m according to whether HIAL (high intensity approach lighting) is or is not (respectively) provided.
But could you land at say Shoreham EGKA where there is no RVR measurement, and visibility reported in the ATIS is obtained by looking at distant landmarks? I was once told that there is no lower limit provided (obviously) you are visual with the runway environment at the MDA.
Those of us who are affected by the apprach ban fly according to their company operating manuals which should contain a conversion table between observed visibility and RVR (usually based upon some ICAO document like this one here So if there is a figure for visibility, there is also an RVR (and an approach ban).
As what next says. I can’t check the link right now so don’t know if its what I am thinking of but there is CMV (Converted Met Vis) which you can use as an RVR for landing but it’s prohibited to be used for takeoff or if the obtained RVR minima is <800m
What I was specifically getting at is whether a criminal prosecution is possible on that basis, on a private flight.
At an airport which reports official RVR, this is possible, and rumour (UK) is that it happens, because ATC are obliged to report every such case to the CAA. You are welcome to search here to see if that rumour is true; there was nothing there last time I looked but maybe I missed something.
But if there is no RVR reporting (from a measurement device next to the runway), how can this be argued, when the pilot can do the same thing he can do with the decision height i.e. nobody knows what he actually sees on the final approach?
Well if there is no RVR and only a visibility given, and you use the CMV table and work out an RVR which is below the limit, then I imagine there is as much chance of being prosecuted IF ATC report it. Maybe the chance of ATC reporting (or working out to see that it would need reported) a CMV approach ban bust is less likely, but if they report it you are still in the wrong.
I don’t really understand your point about not having an RVR being similar to noone knowing if you bust DA, because the reported vis(not RVR) is xxxxm then this will be converted to yyym cmv and this is not subject to what the pilot sees.
My understanding of this is that the approach ban applies to the calculated RVR (met vis multiplied usually by 1.5 or 2.0 depending on lighting and day/night) and that at airports without an RVR monitoring system, ATC are able to do the calculation and enforce the approach ban accordingly. I have heard ATC provide the calculated RVR to CAT in foggy conditions. In this sort of situation the met vis appears to be observed far more often than the normal 30 mins for the atis. I guess this may not apply everywhere for liability reasons etc.
Edit – just found the reference for you in Part NCO.OP.210, which contains the approach ban. It says RVR/VIS which backs up what I said below.
The tower controller has an instantaneous readout of RVR on a screen in front of them where transmissometers are installed and that is what is being read out to the aircraft.
If visibility reported is not sufficient for the Approach, you don’t do it. RVR is only measured up to 1500 or 2000m,and there are plenty of NPAs with visibility requirements above this. The approach ban wording actually states “RVR/visibility” (EU OPS 1.405) so it is still in place.
I have done some hairy approaches in minimum vis/RVR (one in Eastern Europe to a 60m runway with edge lights only in 550m RVR comes to mind). The limits are there for a reason. Even if the RVR is legal, continuing without visual reference is a good way to continue the conversation with a higher power One way or another.
Does the reg actually say that vis reported by the tower, without any way of measuring it, is equivalent legally to the measured RVR?
There is an added angle here that while in the UK, currently, for almost all practical scenarios, any IAP needs ATC sitting in the tower. That AFAIK implies a qualified weather observer has to be present. But what if this changes and you have an IAP to a runway which has a FISO or A/G or, god forbid the mere thought (let’s face it, the USA has not been doing this for decades ), nobody in the tower?
The regulation says “reported visibility”. For untowered approaches in the USA, I believe an AWOS is required. Should EASA get an attack of common sense, I would imagine a similar requirement would be in place.
Peter, have you found a loophole or a quirky regulation that makes you ask? reported vis is not equivalent to RVR, once you multiply it by a predetermined factor then it is.