I don’t think this is a linguistic issue. The issue is with the people who drafted SERA, who took the term “IMC”, commonly understood by most pilots to mean “conditions requiring reference to instruments” or even just “inside cloud”, and “stole” it and gave it a completely new definition.
There was no reason to do this, they could have just as easily used a new term such as “sub-VMC” or whatever or just not used any such terminology at all.
I don’t think the FAR has this issue because they just define VFR minima directly, rather than first defining IMC and then referencing this to define something else. Is that correct?
It is pretty poor that we don’t have a universal definition of IMC and SERA creating one contrary to common usage doesn’t make it so.
Cobalt wrote:
Both definitions are equally valid,
I agree with what you have said in this discussion except this. It is a bad idea to use the same term with different meaning in the same context. I say “in cloud”, “clear of cloud”, “ground in sight”, “fly visually”, “on instruments” etc. to distinguish conditions where you need to use instruments to control the aircraft and where you do not.
ortac wrote:
The issue is with the people who drafted SERA, who took the term “IMC”, commonly understood by most pilots to mean “conditions requiring reference to instruments” or even just “inside cloud”, and “stole” it and gave it a completely new definition.
The “IMC” and “VMC” concepts were not introduced with SERA!
They have been along with their present meaning (although the exact definition has changed over time) in both international and national regulations for a very long time. They were well established when I first learned to fly in 1983.
I don’t think the FAR has this issue because they just define VFR minima directly, rather than first defining IMC and then referencing this to define something else. Is that correct?
I don’t know about the FARs, but SERA does exactly what you ask for! It defines VFR minima (i.e. VMC) directly and then defines IMC to be conditions which are below these minima. I actually quoted the IMC definition from SERA some posts back. Here it is again:
“’instrument meteorological conditions (IMC)’ mean meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling, less than the minima specified for visual meteorological conditions”
ortac wrote:
The issue is with the people who drafted SERA, who took the term “IMC”, commonly understood by most pilots to mean “conditions requiring reference to instruments” or even just “inside cloud”, and “stole” it and gave it a completely new definition.
The current EASA definition of VMC/IMC is exactly the same that I learned during ground school pre-EASA, and pre-JAA. In other words at a time Norwegian regulations were still in effect.
Was the minimum 1500m in those days? That was quite a big reduction for the UK.
I am the last to know the rules on anything 
but under JAA the VFR min was 3000m, unless you had the IMCR in which case it was 1500m (and then you could fly down to 1500m VFR worldwide, where not locally limited otherwise). The funny bit was the 1800m min vis for the IMCR under IFR 
Around 2012 the 3000m came down to the ICAO min of 1500m.
Of course 1500m is instrument flight in all but name, unless you are following the M25 in a helicopter at 200ft But then night flight, on a real night, is instrument flying too.
These rules are nutty as a fruitcake, but that’s the price paid for the existence of VFR and the basic PPL as the most affordable item on the school price list. If you did the obvious thing and offered just IFR, plus an “aerobatic PPL”, you could cut all that crap out. But such a high barrier to entry would kill the GA industry, and nobody wants to do that.
