This debate has been round before.
The pilot in command has final responsibity for the safety of the flight. No one else. It is the pilot in command alone who decides what is safe and what is not and if they make an informed decision that avoiding a CB before being able to get clearance is the safe option then the law backs up that decision 100%.
Yes if one can ask or advise ATC about what is happening then that is the preferred option.
However, I am worried that ATC are saying no-no-no to the idea of (when necessary) avoid first and tell later simply to avoid having 2.5nm between two blips when there should be 3 and this pressure to do something unsafe could lead the less experienced into a lot of trouble.
Thinking of the LTMA situation, there is far too much pressure on people to maintain departure rates when lots of CB's about and that is what causes most of the fear.
If there was traffic avoiding weather all over the place and the avoiding traffic could not get a word in and they subsequently had to rely on TCAS to avoid a collision (not simply a loss of separation) then the biggest question would be why the departure was permitted?
The question always comes round about weatehr being displayed on ATC displays. Every time it is asked of NATS the answer "we have the weather filtered out" comes back..........which was a great answer in the 1970's when it was good not to have aircraft disappearing into the weather.
However, they seem to have not realised that today it is possible to have a colour real time feed from the local weather radar as a selectable overlay on the display when required. The information is fed as far as the ops room but that is all. and the reason why they won't do it - money.
So when I can't get a word in edgeways and use my display of the dangerous area of weather ahead to avoid it in the interests of safety don't complain because if money was not put before safety you could have the same (if not better) information when you need it.
As for the 7700 squawk all I can say is this suits the statisticians perfectly and the printouts will not have an airprox due to weather avoidance wearing two standard (orcam) squwaks.
Next we will have -
ABC123 turning right to avoid.
ATC - Negative continue heading 360 maintain 2000ft
ABC123 is now heading 090 at 3000ft
ATC - You turned and climbed without clearance. I am going to send a report and your stupid captain ass is toast.
ABC123 - can you please include in your report the fact that we avoided opposite direction traffic at our level.
