I don't know IMC, how should I. I'm merely presenting ideas, eager to leran about the topic by ingesting the falsification of them by the people in the know.
Pls. give it a final try.:8

Hmm, groping around in bad weather when you start off vaguely knowing where you are is a LOT different to being in the soup and trying to get out of it. Helicopters have a minimum speed for the stabilising surfaces to kick in, which is mostly around 45 knots, near 70-odd in a Dauphin, so hovering IMC is out.

We used to do ILSs at Belfast down to about 100 feet in our Beavers and I can assure you it is not fun. I certainly wouldn't like to do that in a helicopter.

Phil

Got that. Was only an extreme exaggeration to outline how I depict helicopters being very different from planes.

Interesting. Them Beavers stall at 40kt-ish, you recommended 45kt as min. heli maneuvering speed.

So this is exactly what I'm very intersted in:
why - if I understood correctly - would you do that Belfast thing rather in an IFR-Beaver than an IFR-Heli? :suspect:

As anyone who has flown a Beaver will tell you, they are completely trustworthy :) and, as mentioned above, aeroplanes are inherently more stable, and this particular Beaver stalled at around 30 kts - in fact we often took off across the runway if the crosswind was bad enough. We also had a full IFR fit plus Decca, so we didn't get lost :)

Of course, it was in the military, so things were a little different - we had good reason to go off in bad weather. Certain pilots I know were doing radar approaches in Bell 47s with that basic instrument fit. I was happier doing that in the Scout.

I don't recommend a 45 kts stalling speed in any helicopter - they don't have one. The minimum IFR speed will be in the flight manual

Phil

Guys, I reely think you're being wound up. Surely?!

Must have been interesting times. :ok:

Misunderstanding, I didn't say you do.

'kay, noted.

Are you referring to CAT ? Private vfr flights on top are legal imho.

Swiss cloudbreaking license
 

Some more info on the swiss national license, also called HDF (helicopter departure in fog):

Required conditions: lower cloud ceiling not higher than 200m, max cloud layer thickness 300m, VFR on top. You can do this on controlled airports on the runway (e.g. zurich has published a procedure) or also outside controlled airspace and it's also not even required to start from an airport. There is a common frequency for starts outside controlled aispace.

Again, the main point of this is to get out of an inversion which you cannot underfly (hence the limit of 200m).

Thx. for the info, very interesting!

How does the pilot assert this condition when planning the flight (to the extent of plausible deniability of deliberate violation) ?

Hmm,:8 you mean "VFR over the top" VFR over-the-top - Wikipedia, the free encyclopedia

"VFR on top" is an (FAA defined) IFR term, granted by ATC, not relieving them from seaparation duties!
VFR-on-top - Wikipedia, the free encyclopedia

Just clarifying terms because there might be one or two 'murricans on the forum.

Smart. For pilot to pilot communication or for talking to the FIR admin?

Several ways:
1. Metar from Airport / ask incoming planes
2. Webcams (there are plenty around nowadays)

I meant "VFR on top" in the sense of VMC conditions above the cloud layer.
The common frequency is for blind transmissions (pilot-to-pilot), there is no ATC in uncontrolled airspace. If you start from or ascend into controlled airspace, then of course you talk to the appropriate ATC station.