Approaches to minima (and departure minima)

Peter wrote:

We did this a while ago regarding arrivals and the approach ban, where no RVR was reported, and that IIRC was different i.e. the ATC-reported vis was applicable.

Yep and there is a table and a formula explaining which is the correction coefficient applicable to convert the met vis into CMV in GM4 NCO.OP.110

Just saying that the min RVR is actually 800m unless you have a coupled Autopilot
Granted most have this, but I wonder what coupled means… for example in the C82T in my club, the A/P does not descend on the glideslope

A pilot assessment can replace reported met vis, but not reported RVR.

So with a departure in say 200m, at an airport where no RVR is reported, the pilot cannot be prosecuted (unless there is a witness in the cockpit, presumably).

Especially as with vis anywhere near 400m the tower may not see the runway at all.

That is very interesting!

We did this a while ago regarding arrivals and the approach ban, where no RVR was reported, and that IIRC was different i.e. the ATC-reported vis was applicable.

JasonC wrote:

Not sure allowed in Europe any more. Reported RVR is usually constraining.

Correct. A pilot assessment can replace reported met vis, but not reported RVR.

AMC1 NCO.OP.110 Aerodrome operating minima — aeroplanes and helicopters
TAKE-OFF OPERATIONS
(a) General:
(1) Take-off minima should be expressed as visibility (VIS) or runway visual range (RVR) limits, taking into account all relevant factors for each aerodrome planned to be used and aircraft characteristics. Where there is a specific need to see and avoid obstacles on departure and/or for a forced landing, additional conditions, e.g. ceiling, it should be specified.
(2) When the reported meteorological visibility is below that required for take-off and RVR is not reported, a take-off should only be commenced if the pilot-in- command can determine that the visibility along the take-off runway/area is equal to or better than the required minimum.
(3) When no reported meteorological visibility or RVR is available, a take-off should only be commenced if the pilot-in-command can determine that the RVR/VIS along the take-off runway/area is equal to or better than the required minimum.

At least for N-reg it is the FAA.

Aviathor wrote:

I suppose it would be the country of residence of the operator.

This is surprising – I would expect other options (CAA of country of departure airport or CAA of country of registry).

Flying single engine or multi-engine aircraft involves taking a certain risk for granted. Some are accepting and at ease with more risk than others.

I take off in low visibility and of course hope that the engine will not quit right at that moment. If it would happen, you all will be discussing the case here on this forum. It would be a disaster if the engine did right after rotation in a single engine aircraft, but probably also be a hard situation to manage in a twin-engine aircraft.

It is the same story with night flying single engine aircraft, flying over water, etc. We all accept in one way or the other that flying small piston aircraft comes with more risk than flying on board an airliner.

If others are on board, such as passengers, family members, the wife, then I explain as good as I can what I want to do (low visibility departure) and give them the option to stay and wait or go.

Peter wrote:

It is the time window during which an engine failure would end badly.

Which in a single means departing in fog equals no options should the engine quit.

I have done it but we do need to be realistic that in that scenario you are entirely relying on the engine not stopping.

how do you make the decision to go no go in an SEP?

It is the time window during which an engine failure would end badly.

There are plenty of them in flying though usually they are quite short.

I would not do it in a rented plane